Review of William Lane Craig’s In Quest of the Historical Adam
Part 1: Introduction
William Lane Craig is a well-respected Christian philosopher who has made important contributions to the case for cosmic design from fine-tuning and from the need for a first cause to explain the origin of the universe. His important books in both scholarly and popular venues include The Kalam Cosmological Argument; Theism, Atheism, and Big Bang Cosmology, co-written with Quentin Smith and published by Oxford University Press; Time and the Metaphysics of Relativity, published by Kluwer Academic; and The Blackwell Companion to Natural Theology from Wiley-Blackwell, co-edited with J. P. Moreland. His work has had a profound and positive impact on many people.
In recent years Dr. Craig has explored new intellectual territory: the origin of humans. His study has culminated in a new book, In Quest of the Historical Adam, which I will be reviewing here in a multipart series. Craig convincingly argues that mainstream science can be reconciled with a traditional view of Adam and Eve — a historical couple who were specially created as the sole progenitors of humanity. I applaud his careful scholarship which plausibly argues that Adam and Eve were real people who could have been members of Homo heidelbergensis (criticisms of this taxon aside). His specific thesis doesn’t necessarily have to be true, but it could be true, and this shows that it’s not scientifically problematic to take a truly “traditional” view of Adam and Eve. This effectively answers many other evangelicals who have argued that Adam and Eve are scientifically impossible.
But More Needs to Be Said
Many readers will also be interested in Craig’s analysis of Genesis, which represents the first 200 pages — over 50 percent of the book’s body! These sections are devoted to exploring the nature of “myths” and identifying the literary genre of Genesis 1-11, which he concludes is “mytho-history.” Although Craig is careful to emphasize that “myth” does not necessarily mean “false,” his arguments entail the conclusion that Genesis 1-11 contains myth-like “fantastical elements” that are “palpably false.” Many readers will feel that his perspective fails to adequately engage with major models that are advanced by people of faith to reconcile Genesis with science, including both young and old earth creationist models. As an old earther myself, I was concerned that Craig did not adequately engage with old earth interpretations. Though I am not a young earther, from my understanding of what they propose, I believe that young earth creationists will feel that Craig badly misrepresents the scientific claims of their models. I will explore this in Part 2.
Craig’s book provides highly informed discussions of the paleoanthropological, archaeological, neurological, and genetic evidence regarding human origins, but his arguments often incorporate evolutionary assumptions which are doubtful. For example, Craig is too credulous towards evolutionary explanations of the origin of the human mind which amount to miracle mutations, as well as common evolutionary notions that pseudogenes are “junk DNA” that support common ancestry. He misses a key deficiency in evolutionary explanations: a conspicuous gap between the genus Homo and our supposed ape-like australopithecine ancestors in the hominid fossil record. Although Craig does not recognize it, key neurogenetic evidence raised in his book actually suggests a potent mathematical challenge to the Darwinian evolution of humans. I also believe he sells Homo erectus short as a potential candidate for Adam and Eve. These issues will be the focus of Parts 3 and 4.
A Lesson for Evangelical Intellectuals
Most importantly, there is a valuable lesson to be learned from the backstory surrounding Craig’s book: Evangelical intellectuals often assume that challenging evolution is what brings disrepute upon the church. Even some evangelical leaders push this view, hoping to bully evangelicals into staying silent about doubts about Darwin. But recent debates over Adam and Eve have turned this stereotype on its head. Over the past decade it has been evangelical scientists who embraced mainstream evolutionary ideas and told the church that they must reject 2,000-year-old doctrines on Adam and Eve, that got the science wrong. This led to nearly a decade of leading theistic evolutionists wrongly pushing the idea that Adam and Eve as historical individuals are false. Only after Darwin-doubting scientists in the intelligent design camp were willing to challenge the status quo did the truth become clear that science has not refuted Adam and Eve.
Evangelical Christians who continue to embrace evolutionary ideas in the absence of confirming evidence continue to bet on the wrong horse, and threaten to repeat these mistakes. This is the moral of the story over recent debates over Adam and Eve — and it isn’t emphasized by Craig because he still thinks it is unwise to challenge biological evolution. Indeed, Craig continues to rely upon BioLogos arguments that pseudogenes are “broken” and non-functional junk DNA that we share with apes, thereby demonstrating our common ancestry. Those arguments are increasingly contradicted by evidence presented in highly authoritative scientific papers which find that pseudogenes are commonly functional, and they ought not be assumed to be genetic “junk.” In relying upon dubious evolutionary arguments that are increasingly refuted by the technical literature, Craig may be repeating the very mistake that led previous evangelicals to think Adam and Eve did not exist. This story will be told in Parts 5 and 6 of this review.
Part 2: Is Genesis “Mytho-History”? As a Guide to Scripture, William Lane Craig’s Book Falls Short
The first 200 pages of William Laine Craig’s new book, In Quest of the Historical Adam, are largely devoted to a detailed discussion of the nature of myths, mythic literature of the Ancient Near East, and how we can determine whether Genesis contains myth-like elements. This is far outside my areas of expertise, and it also represents topics that we don’t cover much here at Evolution News. But since Craig’s discussion of myth accounts for 50 percent of the entire body of his book, it should be addressed in any review. So I will devote this one part of my six-part review to the topic, even though it is far afield from the science of intelligent design.
Craig’s treatment of “myth” is nuanced and he is careful to correct the common stereotype that calling something a “myth” necessarily entails its being false. He convincingly argues that some elements of Genesis, such as the genealogies, are intended to be historical. I also appreciated his rejection of Tremper Longman and John Walton’s view that Genesis 1-11 contains “hyperbole” (pp. 127-128). More than anything else in this section of his book, I applaud Craig’s conclusion that Genesis teaches that Adam and Eve were real, historical people — a conclusion he strengthens in his section looking at the New Testament. Craig summarizes his findings by arguing that Christians should “affirm the historicity of Adam and Eve” as “the fount of all humanity, the genealogical ancestors of every human being who has ever lived.” (p. 363) Craig should be commended for carefully supporting this important conclusion.
But oddly, in a book devoted to Adam and Eve, Craig goes much further in his analysis of Genesis than merely assessing what it says about the parents of humanity. He spends nearly 200 pages (again, some 50 percent of the book) investigating the literary genre of Genesis and ultimately concludes that Genesis 1-11 includes many myth-like elements, and that these chapters represent “mytho-history.” His arguments may fail to satisfy certain Biblical scholars who may feel that he redefines the meaning of “mytho-history.” John Oswalt, a prominent biblical scholar, has raised significant questions about Craig’s use of the term. As Oswalt put it in an interview, “‘mytho-history’ is an oxymoron. Myths are a-historical by nature.”
“Fantastical Elements” that Are “Palpably False”?
You’ll never find a specific sentence in Craig’s book that says, “Genesis 1-11 makes statements that are factually and historically wrong,” but a careful reading shows this is what he believes and intends to argue. Craig argues that Genesis 1-11 contains, in his words, various “inconsistencies” and “fantastical elements” that “if taken literally, are so extraordinary as to be palpably false” (pp. 104, 203). This is certainly a major part of his conclusion that parts of Genesis are “myth.”
Because God can perform miracles, Craig is careful to justify excluding miracles from those elements that he considers mythological, “fantastical,” or “false.” But he doesn’t seem to apply this rule consistently, and many of Craig’s judgments here seem subjective. That is, they appear to be based upon his personal feelings about what a reasonable God would do, much like Stephen Jay Gould’s dubious arguments from incredulity about how a “sensible God” would never create certain features of biology. (The Panda’s Thumb, p. 20.) For example, Craig believes that God walking in the Garden in Genesis 3, the lack of an explanation for the origin of Cain’s wife in Genesis 4, or Satan speaking through the serpent, represent “inconsistencies” or “fantastical elements.” But many Christians would not see these elements as problematic in any way. It’s also difficult to see how Craig’s form of subjective analysis could prevent many other stories throughout the rest of the Bible from suffering a similar “mytho-historical” fate — for example Egyptian magicians performing miraculous signs in Exodus, or even Satan possessing certain figures in the Gospels. In an article at First Things Craig elaborates on this form of argument:
Other aspects of the narratives would be fantastic, even to the Pentateuchal author himself, if taken literally. The idea of an arboretum containing trees bearing fruit that, if eaten, would confer immortality or yield sudden knowledge of good and evil must have seemed fantastic to the author. We are not dealing, after all, with miraculous fruit, as if God would on the occasion of eating supernaturally bestow upon the eater immortality or knowledge of good and evil against his divine will.
There you have it: In Craig’s subjective judgment the fruit of knowledge is a “fantastical element,” therefore Genesis is mytho-history. God is apparently disallowed from creating a fruit that would have this effect upon human beings. Craig rightly rejects naturalism when it is imposed upon God to prevent Him from doing miracles (p. 105). But God is not the only supernatural being or element described in the Bible, and Craig seems to wrongly concede naturalism when applied to to other supernatural events or elements, perhaps caused by other supernatural beings. For many Christians who believe that Genesis represents history, not myth (and also not “mytho-history”), Craig’s arguments will likely be unconvincing, create confusion, and be frustrating.
Myth in the Genesis Creation Accounts?
Many of Craig’s other arguments for “fantastical elements” are less subjective but depend on a surprisingly inadequate analysis. For example, he concludes that a young earth interpretation is the only possible hermeneutical reading of Genesis 1-11. Since science does not support a young earth, he concludes, the young age of the earth implied by Genesis is a “fantastical element” that is “palpably false.” That’s his argument in a nutshell, but it requires him to reject common methods developed by both young and old earthers to reconcile various interpretations of Genesis 1-11 with various scientific models.
Getting Old Earth Creationist Thinking Wrong
As an old earther, I was dismayed by Craig’s failure to engage with common old earth interpretations of Genesis. Completely absent is any mention of a standard argument that the Hebrew word “yom,” which is commonly translated as “day” in English translations of Genesis 1, can also indicate an indefinite period of time. Nor does Craig recognize the general chronological consistency between the ordering of events in Genesis 1 and the findings of mainstream science, including (in this order): the origin of the universe, the emergence of light, the formation of land on Earth, the origin of plants, the appearance of the sun through Earth’s atmosphere, the origin of fish, origin of birds, origin of mammals, and origin of humans. Old earthers have developed detailed models for reconciling Genesis with the mainstream cosmological timescale and Craig interfaces with almost none of these arguments.
Craig also seems to inaccurately portray certain common old earth creationist claims about the flood. He fails to recognize that many old earth creationists do not believe that other hominids (such as Neanderthals) who may have survived a local flood were descendants of Adam. To get into specifics, the Genesis flood account is traditionally said to have wiped out all humanity — i.e., all descendants of Adam and Eve (except for Noah and his family). But Craig maintains that a model of a local flood confined to the Mesopotamian region could not have wiped out all humans because hominids were already widespread around the earth at whatever time such a Mesopotamian-specific flood might have occurred. As he puts it, the idea that “antediluvian mankind inhabited only the Persian Gulf region” is “fantastic” in light of modern paleoanthropology (p. 124).
What Craig apparently fails to appreciate is that many old earth creationists hold that not all members of Homo are related through common ancestry. They would maintain that at some point God created Adam and Eve in the Middle East — but Adam and Eve were created separately from all hominids extant at that time, thereby excluding Neanderthals, Denisovans, and others from Adam’s line. (Please note: I am not necessarily committed to the view that Adam and Eve were unrelated to Neanderthals or Denisovans, I’m just describing a common old earth creationist position that Craig seems not to appreciate.) Under this view, Adam and Eve’s progeny spread throughout the Mesopotamian region, and were wiped out in the (local) flood. But other members of Homo that existed at that time (whether Neanderthals, Denisovans, or archaic Homo sapiens), who were not necessarily made in the image of God and were unrelated to Adam’s line, did not necessarily die out in the flood. Under this model, if these other hominids — who lived far from Mesopotamia — survived the local flood then there is no violation of the biblical account’s claim that humanity was wiped out in the flood. That is because “humanity” — i.e., the descendants of Adam and Eve — were not related to these other hominids. Craig seems not to appreciate this common method of resolving the existence of globally widespread hominids who survived a local biblical flood.
Getting Young Earth Creationist Thinking Wrong
Additionally, I know enough about young earth creationist thinking to say that many young earthers would feel that Craig severely mischaracterizes their models. That’s true in particular of his claims that young earth creationists believe that all dinosaur diversity must evolve, and all plate tectonic movements must occur, in a 300 year period after the flood. Craig claims that young earthers hold that after the flood Noah released dinosaurs from the ark after which “they spread throughout the earth and evolved into all the known species of dinosaur,” meaning that “the entire history of dinosaur evolution and extinction must be compressed into the space of less than three hundred years” (p. 130). This does not seem to be what young earthers claim. (Again, this is not my view—I’m just articulating what young earthers say.) Most young earth creationists I’m aware of would say that the full panoply of dinosaur species that we know of perished during the flood (hence the extinction and hence the fossil record). Yes, they would hold that Noah took certain representative dinosaurs on the Ark, but they would surely not argue that after the flood dinosaurs necessarily evolved into “all the known species of dinosaur” that existed prior to the flood. Rather, they hold that a great many of those species perished during the flood, and did not re-evolve after it.
Likewise, Craig requires young earth creationists to propose that plate tectonics “separated the primordial supercontinent into the world’s continents … within about three hundred years following the end of the flood” (p. 131). This, however, is not what young earth creationists say. Instead, most major young earth groups today propose that most plate tectonic movements took place during the flood, not after it. Craig’s descriptions of young earth creationist thinking are simply not in line with what they believe.
Failing to Satisfy
I want to reiterate that many of the views discussed above do not represent my own views, nor do they have anything to do with intelligent design. My point is this: Craig’s conclusion that Genesis 1-11 is “mytho-history” will likely satisfy neither young nor old earth creationists. Many young earthers will likely feel that he is not engaging with their science. Meanwhile, many old earthers will likely feel that he is not engaging with their theology or hermeneutics, nor with important anthropological aspects of their model.
Craig’s detailed investigation into the nature of myth is commendable. Ultimately, though, he fails to adequately engage with models of reconciling Genesis with science and seemingly makes a bee line straight to the conclusion that Genesis 1-11 is incompatible with science and therefore is “mytho-history.” This is going to alienate a lot of people who have worked hard — harder than he gives them credit for — to reconcile Genesis 1-11 with science. As a guide to Scripture, in other words, this book falls short. What about as a guide to science? I’ll turn to that in the next section of my review.
Part 3: Missed Opportunity: Passing over Scientific Problems with Human Evolution
In his book In Quest of the Historical Adam, William Lane Craig’s rhetorical strategy is essentially to accept whatever mainstream evolutionary paleoanthropology says, and see if Adam and Eve can still stand. As he put it in an interview with Christianity Today, his “hope [is] that, by showing there is no incompatibility between contemporary evolutionary science and the affirmation of a single human pair at the headwaters of the human race, we can prevent that obstacle to faith.” Even a review of the book in the journal Science observes that Craig “takes evolution as a given.” In locating Adam and Eve within the species Homo heidelbergensis, Craig’s goal is to present a position of “reasonable faith,” and his tactical approach could indeed be useful for those who want to claim that the Bible is not in contradiction with mainstream evolutionary science. That’s fine as far as it goes. But this strategy means that sometimes Craig assents to evolutionary assumptions and arguments that are highly dubious, and he misses opportunities to point out severe weaknesses in evolutionary models.
Miracle Mutations and the Evolution of Human Intelligence
Craig focuses on various “crucial genetic mutation[s]” which occurred “in the human lineage since our last common ancestor with chimpanzees.” These could “explain the extraordinary expansion of the brain unique to human beings.” His primary examples involve a single base pair substitution in the gene ARHGAP11B and three human-specific NOTCh2NL genes (pp. 277, 278). He acknowledges that “we do not know” if these mutations had “any direct effect on language ability.” Yet he later cites human-specific features of two other genes that may be necessary for speech. These genes are AUTS2 (which Craig admits has an “unknown” function), and FOXP2 (which Craig argues “seems to be necessary for human speech”) (p. 325). In 2018 the FOXP2 story was discredited because the genetic signal that was thought to exist in the gene turned out to be a false statistical artifact,1 making it surprising that Craig continues to cite it.
Thus, aside from FOXP2 (which has been discredited), it’s not entirely clear what import these genetic traits have for human language and cognition. But let’s assume for the sake of argument that all of these “mutations” are necessary — though surely not sufficient — to explain humanity’s advanced cognitive and linguistic abilities. Craig never makes it exactly clear whether he views these mutations as arising and spreading via standard evolutionary mechanisms, or as having been guided by God’s intervention in the natural world. At one point he suggests the mutations could be “divinely caused” (p. 307), but his general framing lacks such qualifications, suggesting they are ordinary “mutations” that arose via standard evolutionary mechanisms. Writing in First Things, Craig proposes that “God selected two [hominids] and furnished them with intellects by renovating their brains and endowing them with rational souls” — which sounds like “divinely caused” mutations. In his book he is open to divine causation in the creation of Adam and Eve, but does not seem strongly committed to it:
The radical transition effected in the founding pair that lifted them to the human level plausibly involved both biological and spiritual renovation, perhaps divinely caused. (p. 376, emphasis added)
In First Things Craig then proposes that Adam and Eve were not as cognitively advanced as modern humans, and postulates that humanity experienced standard evolutionary changes after Adam and Eve including some that would “emerge slowly through environmental niche construction and gene-cultural coevolution” to evolve the more advanced brains we have today.2 What this suggests is that not only does Craig seem to propose or allow that many (if not all) of humanity’s intellectual abilities evolved via natural mechanisms, but he effectively believes we evolved upward after Adam and Eve — a model which contrasts sharply with the traditional Christian view that humanity has fallen from Adam and Eve’s initial state.
In his book it’s never quite clear if Craig thinks that the specific mutations he discusses occurred via standard evolutionary mechanisms, God’s direct intervention, or some kind of hybrid of the two. To give one of multiple examples, he says, “The most plausible scenario is that in a common ancestor of humans, Neanderthals, and Denisovans, the ancestral PDE4DIP-NOTCH2NL pseudogene was repaired by an ectopic gene conversion from NOTCH2. This event may have been crucial to human evolution…” (p. 279) To give another example, when discussing ARHGAP11B, he writes that Neanderthals, Denisovans, and humans,
share in this crucial genetic mutation that helps to explain the extraordinary expansion of the brain unique to human beings. Indeed, since the mutation occurred in the species ancestral to Neanderthals, Denisovans, and Homo sapiens, these findings are consistent with the humanity of someone belonging to a large-brained ancestral species like Homo heidelbergensis, in which the mutation occurred. (p. 278)
Perhaps these mutations were “divinely caused.” Yet in this retelling, whatever “divine causation” might mean (in Craig’s view), it appears indistinguishable from standard evolutionary explanations. Let’s set aside Craig’s ambiguity about what he means and just ask: What is the raw data here and does it demand assent to an evolutionary view?
At most, the data he cites simply shows that humans, Neanderthals, and Denisovans share certain similar genes and genetic traits which are involved in our brain development and linguistic abilities — genes and genetic traits not found in living apes. This is not at all surprising since Neanderthals and Denisovans were highly similar to us, are thought to have had advanced cognitive abilities, and may even belong within our own species Homo sapiens. The evidence he recounts is not evidence of evolution. Rather, it simply identifies human-specific genetic features that probably help endow us with our advanced cognitive abilities. Merely identifying important genetic traits does not necessarily tell us that they arose by blind evolutionary mechanisms. After all, these traits could have been intelligently designed or even specially created by God in the creation of Adam and Eve.
But Craig’s arguments typically seem to treat these mutations no differently from blind evolutionary events, which suddenly produced humanlike intelligence in some early hominid. Those of us who have been around the debate over evolution for a while have heard these kinds of miracle mutation stories before, and we have multiple reasons to be skeptical.
Reasons for Skepticism
First, miracle mutation accounts of the origin of human cognition imply a teleology and design to evolution that contradict an unguided evolutionary story. If our cognitive abilities suddenly evolved by just one or two single mutational events, that implies that our profound human intelligence was sitting on a precipice, just waiting for certain specific mutations to occur before modern human minds could arise. But how did our minds get to that evolutionary precipice, where just one or two mutations could produce everything from Lao Tzu to Beethoven to Einstein? The idea implies a teleological, directed, and designed course to the origin of our cognition. Craig seems open to this option, but he never says it is his preference.
Second, miracle mutation accounts of the origin of human cognition lack credibility and often go belly-up upon closer scrutiny. In The Language of God, Francis Collins asserted that a few specific changes in FOXP2 somehow created our major linguistic abilities.3 An article in Time Magazine that same year similarly asserted that two mutations in FOXP2 could have caused “the emergence of all aspects of human speech, from a baby’s first words to a Robin Williams monologue.”4 More recently Yuval Noah Harari argued in his book Sapiens that humans experienced some kind of a “Tree of Knowledge mutation” that occurred due to “pure chance” and caused a “cognitive revolution.”5
Such arguments that one or a few random mutations magically created humanity’s advanced intellectual abilities strain credulity. The origin of human cognition and speech would have required many changes that represent a suite of complex interdependent traits. Two leading evolutionists writing in a prominent text on primate origins explain that human language could not evolve in an abrupt manner, genetically speaking, because many genetic changes would be necessary:
Bickerton’s proposal of a single-gene mutation is, I think, too simplistic. Too many factors are involved in language learning — production, perception, comprehension, syntax, usage, symbols, cognition — for language to be the result of a single mutation event.6
Humans are quite different because they possess language, which underlies every major intellectual achievement of humanity. This discontinuity theory is implausible because evolution cannot proceed by inspired jumps, only by accretion of beneficial variants of what went before.7
These authors are correct to reject such “single mutation event” hypotheses — and would be justified in doing the same for two or three mutation events because human cognition is vastly too complex to arise in such a fashion.
Third, Darwinian evolution claims that these traits must arise and spread via random mutation acted upon by natural selection (and other standard evolutionary mechanisms such as genetic drift) — blind processes that operate without any intelligent oversight. Such a blind trial-and-error mechanism is highly inefficient at producing new features that require multiple mutations in order to provide an advantage. This is especially true when it comes to an advanced biological feature such as human intelligence, which probably requires numerous complex genetic traits. This suggests a potential challenge to the neo-Darwinian evolution of human intelligence.
Too Many Mutations, Too Little Time
To understand this challenge, let’s consider a seemingly simple example. In 2004 a study in Nature proposed that a single mutation that inactivated a protein could cause “marked size reductions in individual muscle fibres and entire masticatory muscles” leading to “loss of masticatory strength,”8 which could have loosened jaw muscles, allowing our brains to grow larger. A news story widely circulated, titled “Missing link found in gene mutation,” framed the finding this way: “an ancient genetic mutation for weaker jaws helped increase brain size, a twist that first separated the earliest humans from their apelike ancestors.”9 The story sounds plausible, but there’s more to it. Leading paleoanthropologist Bernard Wood noted that this mutation alone could never have provided a selectable advantage, and would have required additional changes:
The mutation would have reduced the Darwinian fitness of those individuals. … It only would’ve become fixed if it coincided with mutations that reduced tooth size, jaw size and increased brain size. What are the chances of that?
We thus have a situation where multiple coordinated mutations would be necessary to provide the advantage. Yet a 2008 population genetics study in Genetics found that to obtain only two specific mutations via Darwinian evolution, “for humans with a much smaller effective population size, this type of change would take > 100 million years.” The authors admitted this was “very unlikely to occur on a reasonable timescale.”10 In other words, when a trait requires multiple mutations before an advantage is gained, it would require more than 100 million years within a species such as ours.
Craig did not cite the above example in his book, but it is highly analogous to the examples he does raise. He cites at least three mutational events (some of which might themselves have required multiple point mutations) as necessary for the advent of human intelligence. Undoubtedly, numerous complex mutational events would be required to transition from the apelike australopithecine intellect of our supposed ancestors to modern human cognition. If the Genetics paper cited above is correct, then if among these events, just two point mutations were ever required to yield an advantage, they would be extremely unlikely to arise via blind evolution in a population of hominids on the timescale allowed by the fossil record (i.e., ~750,000 years since the appearance of Homo heidelbergensis, or ~2.5 million years since our genus Homo supposedly evolved from australopithecines).
This represents a potent challenge to the neo-Darwinian evolution of human cognition that flows directly out of the mathematics of population genetics. Unfortunately, because Craig never directly disputes mainstream evolutionary theory, his readers miss out on an opportunity to hear about this powerful challenge to neo-Darwinism.
Another Missed Opportunity to Challenge Human Evolution: Fossils
Craig doesn’t spend much time discussing the origin of the genus Homo, although he does cite anthropologist Ian Tattersall, arguing for “the futility of trying to divide what is now a very extensive hominid record between australopiths and Homo” (p. 256). In his quest to fit Adam and Eve within mainstream evolutionary science, he misses another major opportunity to point out a serious deficiency in the evidence for human evolution: the lack of fossil evidence documenting a transition from the ape-like australopithecines to the human-like Homo. This “gap” in the fossil record is well attested in the literature.
One Nature paper noted that early Homo erectus shows “such a radical departure from previous forms of Homo (such as H. habilis) in its height, reduced sexual dimorphism, long limbs and modern body proportions that it is hard at present to identify its immediate ancestry in east Africa”11 — or anywhere else for that matter. Another review similarly notes, “…it is this seemingly abrupt appearance of H. erectus that has led to suggestions of a possible origin outside Africa.”12 Likewise, a paper in the Journal of Molecular Biology and Evolution found that Homo and Australopithecus differ significantly in brain size, dental function, increased cranial buttressing, expanded body height, visual, and respiratory changes, stating:
We, like many others, interpret the anatomical evidence to show that early H. sapiens was significantly and dramatically different from… australopithecines in virtually every element of its skeleton and every remnant of its behavior.
Noting these many differences, the study called the origin of humans, “a real acceleration of evolutionary change from the more slowly changing pace of australopithecine evolution.” It stated that such a transformation would have required radical changes: “The anatomy of the earliest H. sapiens sample indicates significant modifications of the ancestral genome and is not simply an extension of evolutionary trends in an earlier australopithecine lineage throughout the Pliocene. In fact, its combination of features never appears earlier.” These rapid and unique changes are termed “a genetic revolution” where “no australopithecine species is obviously transitional.”13
For those unconstrained by an evolutionary paradigm, it’s not obvious that this transition took place at all. The stark lack of fossil evidence for this hypothesized transition is confirmed by three Harvard paleoanthropologists:
Of the various transitions that occurred during human evolution, the transition from Australopithecus to Homo was undoubtedly one of the most critical in its magnitude and consequences. As with many key evolutionary events, there is both good and bad news. First, the bad news is that many details of this transition are obscure because of the paucity of the fossil and archaeological records.
As for the “good news,” they admit: “[A]lthough we lack many details about exactly how, when, and where the transition occurred from Australopithecus to Homo, we have sufficient data from before and after the transition to make some inferences about the overall nature of key changes that did occur.”14 In other words, the fossil record shows ape-like australopithecines (“before”), and human-like Homo (“after”), but not fossils documenting a transition between them. In the absence of intermediates, we are left with inferences of a transition based strictly upon the assumption of evolution — that an undocumented transition must have occurred somehow, sometime, and someplace. Evolutionists assume this transition happened, even though we do not have fossils documenting it.
Similarly, the great evolutionary biologist Ernst Mayr recognized the abrupt appearance of our genus:
The earliest fossils of Homo, Homo rudolfensis and Homo erectus, are separated from Australopithecus by a large, unbridged gap. How can we explain this seeming saltation? Not having any fossils that can serve as missing links, we have to fall back on the time-honored method of historical science, the construction of a historical narrative.15
Another has commentator proposed that the evidence implies a “big bang theory” of the appearance of Homo.16
This large, unbridged gap between the apelike australopithecines and the abruptly appearing humanlike members of genus Homo challenges evolutionary accounts of human origins. Unfortunately Craig mentions none of this problematic evidence in his book. While he convincingly shows that Adam and Eve could be located within an evolutionary scenario, his readers are deprived of opportunities to learn why an evolutionary scenario might not be the right answer, after all.
Part 4: Traditional or Not? Assessing William Lane Craig’s Model on Adam and Eve
It is possible to reconcile a view of Adam and Eve as a historical couple who were ancestors of humanity with mainstream science. This is perhaps the major message of William Lane Craig’s 400+ page book, In Quest of the Historical Adam, and it is well argued.
To summarize his main conclusion: Craig identifies Adam and Eve as members of the species Homo heidelbergensis. His primary arguments for this proposal are (1) that Neanderthals, Denisovans, and Homo sapiens all show advanced cognitive ability, and therefore must all be descendants of Adam and Eve. If this is correct, Craig infers, then Adam and Eve must have belonged to a species ancestral to those various groups — and mainstream paleoanthropology has proposed that Homo heidelbergensis could have fit into that position in the human family tree. Moreover, he finds that (2) Homo heidelbergensis is also thought to have had a large brain and could have been highly intelligent, consistent with this species having been created in the image of God. Further, when Craig considers the genetic evidence, (3) multiple analyses have found that modern-day human genetic diversity could have arisen from an initial pair that lived at least ~500,000 years ago, and this includes the precise time range when Homo heidelbergensis is thought to have lived. This conclusion may not necessarily be true, but it’s plausible.
Is This a “Traditional” Adam and Eve?
But what kind of Adam and Eve is Craig defending? Is it the “traditional” Adam and Eve where they are miraculously created de novo by God and are our sole genetic progenitors? It’s not clear.
At times Craig claims to defend a “traditional” view of the “original human pair, miraculously created by God a few thousand years before Christ. They are the parents of the entire human race, so that every human being who has ever lived on the face of this planet is descended from them.” (p. xii) That description certainly incorporates some very important aspects of the “traditional” view. But as we saw in the previous installment, his model accepts many evolutionary assumptions, and as we will see in a subsequent post Craig at points defends human-ape common ancestry — making it difficult to see how his model fits with Adam and Eve having been “miraculously created de novo.”
Craig’s description of Adam and Eve would be closer to the traditional view if we added the word “sole” before the word “parents.” And indeed, at points Craig seems to affirm this possibility as well, acknowledging that the scientific evidence supports “a bottleneck of two” and an initial pair who were “our sole genetic progenitors” (p. 353). This is all good.
But does Craig require or even advocate that Adam and Eve are our “sole genetic progenitors”? It’s not clear. He mentions the work of Joshua Swamidass who has promoted the “interbreeding” or “admixture” hypothesis where Adam and Eve are not our sole genetic ancestors because their offspring interbred with other hominids that evolved from a common ancestor we shared with apes. This is called the “genealogical Adam and Eve” hypothesis where Adam and Eve are genealogical ancestors of everyone alive today — though they are not our sole genealogical or genetic ancestors. As Craig writes:
Some have appealed to interbreeding with other evolved hominin species in order to explain how Adam and Eve could have been de novo creations from inanimate material and yet their descendants bear such striking genetic similarity to chimpanzees, including broken pseudogenes that have ceased their original function. (p. 378)
At this point Craig seemingly turns away from this hypothesis because it implies humans mating with non-human hominids—tantamount to bestiality:
No such appeal to interbreeding is necessary if we envision Adam and Eve as emerging from a hominin population that shared common ancestry with chimpanzees and other great apes. Indeed, on the view proposed here, Adam and Eve could be our sole genetic progenitors, whose descendants never fell into bestial relations with nonhuman hominins or at least produced no descendants from such liaisons. (p. 378)
Nonetheless, Craig does allow at various points the possibility that Adam and Eve’s descendants “may or may not have interbred” with these nonhuman hominins (p. 354) and even says “the existence of a historical Adam and Eve need not imply their sole genetic progenitorship … we do not have any idea whether there were offspring of such unions [between Adam and Eve’s descendants and other hominins] that had genetic input into the human line.” (p. 355) In his conclusion he again allows and even anticipates this possibility, writing: “If there were sexual encounters with nonhuman hominins, these would be cases of bestiality, contrary to God’s will for humanity, though not entirely surprising for a fallen race.” (p. 378) So Craig seems quite open to the interbreeding hypothesis after all.
Pseudogenes as Non-Functional Junk
The underlying problem for Craig’s model is his assumption that pseudogenes are non-functional “broken” junk DNA that he thinks show we have some genetic connection with apes in our DNA. He thinks this because God would not create broken genes in two different species; the broken DNA implies we share a common ancestor. Once he accepts this assumption (which will be critiqued in Part 6 of this review), there seem to be two options for him to explain how humans came to have “broken pseudogenes” in our DNA:
(1) Allow for miraculous and de novo creation of Adam and Eve, but their progeny interbreed with an evolved population of hominids not created in the image of God, donating their “broken pseudogenes” to Adam and Eve’s descendants.
(2) Propose that Adam and Eve are directly descended from some common ancestor we share with apes (from which they obtained these “broken pseudogenes”), and they are our sole genetic ancestors.
The problem with Craig (at times) allowing option (1) is that then Adam and Eve are not our sole genetic ancestors — a thesis he claims to defend in the book. The problem with Craig (at times) allowing option (2) is that then Adam and Eve evolved naturally and were not specially or miraculously created de novo — a thesis he also (at times) seems to want to defend in the book. Moreover, if Craig wants to defend both the claims that Adam and Eve were miraculously created by God AND are our sole genetic ancestors — i.e., if he wants to defend the traditional Adam and Eve — then I don’t see how he can either affirm human-ape common ancestry or the mixture of Adam’s line with non-human hominids — both claims he affirms at various points in his book.
In other words, I don’t know how Craig can affirm (A) the miraculous and de novo creation of Adam and Eve, (B) Adam and Eve as our sole genetic ancestors, (C) human-ape common ancestry, and (D) allow human mixture with non-human primates all in a single model. (A) is incompatible with (C), and (B) is incompatible with (D). Moreover, Craig at times says he wants to affirm a “traditional” Adam and Eve, where (A) and (B) are necessary components of any “traditional” model. But (C) and (D) are both incompatible with a traditional Adam and Eve, because under (C) Adam and Eve aren’t specially created, and under (D) they aren’t our sole genetic ancestors.
As a result, I’m having trouble making sense of exactly what his model holds. And it seems I’m not alone. A review of the book in journal Science expressed similar confusion:
we eventually learn that his model allows for an unspecified amount of admixture from other hominin lineages into the descendants of Adam, eliminating the need for such a tight bottleneck. A more clearly stated hypothesis in this section would have saved the reader time and frustration.
Perhaps Craig allows some ambiguity so that both those who want a truly “traditional” Adam and Eve and those who want an “evolutionary” Adam and Eve are comfortable with his argument. But I am someone who wants to know if a “traditional” Adam and Eve are possible, and I hope this review helps to clarify some of that ambiguity.
While I believe that Craig has shown that even evolutionary science allows Adam and Eve could have been our “ancestors” in some sense, evolutionary science requires that they are not our “sole ancestors” and/or they weren’t miraculously created de novo. So I don’t think Craig has shown that evolutionary science is compatible with a “traditional” Adam and Eve, because I don’t think such a reconciliation is possible.
For me the solution to the quandary — which also allows us to restore a traditional Adam and Eve (A and B above) — is to recognize the compelling and rapidly growing body of evidence that pseudogenes are not “broken” DNA but have function — a thesis I will defend in Part 6 of this review. This removes the need to find some way to bring DNA we share with apes into our genome through some strictly natural mechanism (options 1 or 2 above)
But I’m also very interested in paleoanthropology. So let’s set aside the question of exactly what Craig means by his model. Instead let’s ask: Does Craig identify potential candidates in the fossil record for a traditional Adam and Eve who could have been specially created by God as our sole genetic ancestors? Here, I think the answer is yes — and I take it as a praiseworthy accomplishment and an important contribution from his book.
Mainstream Doubts about Homo heidelbergensis
Many are praising Craig for reconciling Adam and Eve with “mainstream” science, and I find his proposal that Adam and Eve could have been represented by something like Homo heidelbergensis to be convincing and plausible. But it’s worth noting that mainstream science does not have a consensus view on whether Craig’s candidate species for Adam and Eve — Homo heidelbergenesis — is a valid taxonomic group. Homo heidelbergensis has been heavily criticized in the paleoanthropology community. A recent article in Evolutionary Anthropology called the species “poorly defined and variably understood,” adding that this taxon “should be abandoned altogether, as it has been poorly defined and used inconsistently.”17 The article continued:
Multiple, often contradictory views on what constitutes H. heidelbergensis make this taxon particularly misleading. Even to non-specialists (e.g., biologists working in other realms, Palaeolithic archaeologists, etc.) H. heidelbergensis represents either (and sometimes paradoxically both) the generalized Middle Pleistocene hominin, or a chronospecies of Neanderthals. Within the palaeoanthropological community, the taxon’s ambiguity has contributed to complex and some-times hard-to-follow discussions: in a single paper, one can find numerous descriptions of the taxon with incompatible hypodigms. More troublingly, newly discovered Middle Pleistocene hominin fossils that cannot easily be assigned to Homo erectus, H. neanderthalensis, or early H. sapiens, still tend to be lumped into this one-size-fits-all taxon, often with a sensu lato qualifier to indicate a nonspecific morphology of a Middle Pleistocene hominin. Alternatively, they are assigned more general or descriptive names like “archaic H. sapiens,” “mid-Pleistocene Homo,” or “Homo sp.,” which do little to convey their evolutionary position.
Indeed, the authors commented on the mid-Pleistocene, the epoch that heralds the appearance of Homo heidelbergensis, and noted that “human evolution during this age is poorly understood, a problem that paleoanthropologists call ‘the muddle in the middle.’”18
Another issue is with Craig’s identification of Homo heidelbergensis as the progenitor of modern humanity is that not all paleoanthropologists consider it to be the most recent common ancestor of Homo sapiens, Neanderthals, and Denisovans, as the article in Evolutionary Anthropology explains:
This taxon was previously considered as the most recent common ancestor (MRCA) of LP [late Pleistocene] hominins, or minimally, the common ancestor of the African and European lineages (i.e., H. sapiens and Neanderthals, respectively). Since the MRCA of the modern human and Neanderthal lineages has been pushed further back in time toward the late Early Pleistocene or very early Middle Pleistocene, the specimens currently assigned to H. heidelbergensis sensu latocannot be considered representatives of the MRCA. This is a particularly pertinent point given that the split between African and Eurasian hominins has been recently proposed to be earlier than the split between the Denisovan and Neanderthal lineages. As such, H. heidelbergensis sensu lato can no longer be considered the root of all African and European hominin lineages.
These criticisms of Homo heidelbergenesis are important to note but they are not necessarily fatal to Craig’s conclusion. After all, fossil hominid relationships are notoriously difficult to interpret (within an evolutionary framework) and there are just about as many opinions on these topics as there are workers in the field. So the fact that the particular team that authored this particular paper doesn’t see H. heidelbergensis as ancestral to the species Homo sapiens, Neanderthals, and Denisovans doesn’t mean Craig’s thesis is necessarily wrong. The data is ambiguous and other teams of mainstream paleoanthropologists would undoubtedly agree with Craig that this is a real species, and very important in the human lineage!
It should be emphasized immediately that each of the “species” supposedly descended from Homo heidelbergensis — Homo sapiens, Neanderthals, Denisovans — are (or were) highly similar both morphologically and genetically. Craig repeatedly notes that the three species could interbreed and produce fertile offspring. Likewise, the Evolutionary Anthropology paper notes, “The extent and frequency of interbreeding among hominin terminal branches in the LP has been well established and recent research indicates that interbreeding can be observed in the Middle Pleistocene.” The article recognizes “strong and growing evidence of migrations as well as gene flow between” Neanderthals and Homo sapiens. This raises questions about whether they ought to even be called separate “species.” As a paper in Annual Review of Anthropology notes, “Neandertals and Denisovans were part of the biological species Homo sapiens.”19 Thus, moving from a “species” like Homo heidelbergensis to modern humans (or to Neanderthals, or to Denisovans) would entail microevolution, or small-scale change within a species.
Selling Homo erectus Short?
In order to explain the high degree of genetic, morphological, intellectual, and behavior similarities between modern humans (Homo sapiens), Neanderthals, and Denisovans, Craig must locate Adam and Eve within a species that can serve as an ancestor to all of these groups. He prefers Homo heidelbergensis as the best candidate species for Adam and Eve, and disfavors Homo erectus. Perhaps Craig is correct, but we should be very careful in excluding Homo erectus from Adam’s line (and the human species). Indeed, the Evolutionary Anthropology paper mentioned above cites other literature20 and proposes that the common ancestor of humans, Neanderthals, and Denisovans pre-dated H. heidelbergensis, and was something that lived much earlier, probably more like Homo erectus.
The name Homo erectus means “upright man,” and according to an article in Nature, it was the “earliest species to demonstrate the modern human semicircular canal morphology,”21 a feature related to the mode of locomotion. Below the neck erectus was extremely similar to us,22 leading an Oxford University Press volume to note that erectus was “humanlike in its stature, body mass, and body proportions.”23 Indeed, several paleoanthropologists have classified Homo erectus as belonging within our own species.24 Lucy discoverer Donald Johanson suggests that if erectus were alive today, it could reproduce with modern humans, meaning we would be members of the same species.25
Craig’s primary argument against erectus being descended from Adam is that the brain size is simply too small to allow for advanced cognitive abilities. When trying to determine what sorts of traits would rule out an individual from being a human, he writes, “a brow ridge would hardly seem sufficient to disqualify a species of Homo from being reckoned human, but a small braincase plausibly would, given the correlation between brain size and cognitive capacity.” (p. 258) Craig may have a point, but it can only be taken so far. While the erectus brain size is on average smaller than that of modern humans, its brain size is nonetheless within the range of modern human variation.26 Moreover, many paleoanthropologists have argued that the correlation between brain size and intelligence is unclear.
Leading paleoanthropologists Bernard Wood and Mark Collard observe: “Relative brain size does not group the fossil hominins in the same way as the other variables. This pattern suggests that the link between relative brain size and adaptive zone is a complex one.”27 Likewise, others have shown that intelligence is determined largely by internal brain organization, and is far more complex than the sole variable of brain size.28 As one paper in the International Journal of Primatology notes, “brain size may be secondary to the selective advantages of allometric reorganization within the brain.”29 Anthropologist Stephen Molnar likewise observes, “The size of the brain is but one of the factors related to human intelligence.”30 Christof Koch, president of the Allen Institute for Brain Science in Seattle, writes that “total brain volume weakly correlates with intelligence … brain size accounts for between 9 and 16 percent of the overall variability in general intelligence.”31 As a demonstration, Koch offers the examples of the Russian novelist Ivan Turgenev (1818-1883) who had a brain weight of 2,021 grams compared with the French novelist Anatole France (1844-1924) who had a brain weight of 1,017 grams. Turgenev’s brain was literally twice the mass of France’s brain, yet both were acclaimed novelists!
Craig correctly observes that archaeological evidence for H. erectus’s intelligence and tool building capacity is limited, but the Cambridge Encyclopedia of Human Evolution observes, “It is very difficult judging whether a particular kind of early human had developed a language, society or art.”32 Nonetheless, we can make certain inferences, a method Craig uses elsewhere for studying intelligence in other ancient hominids.33 Homo erectus remains have been found on islands, where the most reasonable explanation is that they arrived by boat. Karl Wegmann of North Carolina State University said, “We all have this idea that early man was not terribly smart. The findings show otherwise—our ancestors were smart enough to build boats and adventurous enough to want to use them.”34 Daniel Everett, professor of global studies at Bentley University, argues that Homo erectus “sailed to the island of Crete and various other islands. It was intentional: they needed craft and they needed to take groups of twenty or so at least to get to those places.”35 According to Everett, this means:
Erectus needed language when they were sailing to the [Indonesian] island of Flores. They couldn’t have simply caught a ride on a floating log because then they would have been washed out to sea when they hit the current. They needed to be able to paddle. And if they paddled they needed to be able to say ‘paddle there’ or ‘don’t paddle.’ You need communication with symbols not just grunts.36
In an essay in Aeon, he continues:
[S]ailing demonstrates a level of cognitive development rivalling even that of modern humans. The erectus accomplishment of paddling together across one of the strongest ocean currents in the world … required not only cooperation, but also corrections, instructions and commands. Few detailed instructions or corrections can be given without language.37
While there are certainly paleoanthropologists who disagree, there is good circumstantial evidence to make an inference that erectus too was highly intelligent.
Another reason Craig discounts Homo erectus as Adam and Eve’s species is its teeth — specifically, the rate of tooth development as understood from enamel growth patterns in fossilized hominid teeth. In scientific terms, teeth can be plastic and aren’t always a good way to determine relationships, even within primates and hominids. As a paper in Proceedings of the National Academy of Sciences stated:
[O]ur results show that the type of craniodental characters that have hitherto been used in hominin phylogenetics are probably not reliable for reconstructing the phylogenetic relationships of higher primate species and genera, including those among the hominins.38
Theologically speaking, with all of the incredible abilities of humans that reflect our creation in God’s image, it’s difficult to see why the rate at which enamel accumulates on the surface of teeth during the first two years of a child’s life can hardly be taken as good evidence of whether that child bears the Imago Dei and is a descendant of Adam.
Teeth certainly reflect an organism’s diet, lifestyle, and habits, but they are just one variable. A better measure of the erectus lifestyle could be seen in its total energy expenditure (TEE) value, a complex variable related to body size, diet quality, and food-gathering activity. One study found that TEE value, “increased substantially in Homo erectus relative to the earlier australopithecines,” beginning to approach the very high TEE value of modern humans.39 Researchers believe the earliest members of Homo erectus were “more similar to modem humans than to the earlier and contemporaneous australopithecines,” due to their “larger relative brain sizes, larger bodies, slower rates of growth and maturation, dedicated bipedal locomotion, and smaller teeth and jaws,”40 and “major changes” in diet and foraging behavior.41 Together, these features reflect “a lifestyle that was more similar to that of modern humans than that inferred for earlier and contemporaneous hominins.”42
Again, it’s possible that Craig’s thesis is correct and Adam and Eve belonged to Homo heidelbergensis rather than Homo erectus. I want to make this clear: his thesis is plausible, well-argued, and worth taking very seriously! But all of these members of Homo are highly similar — so similar, as noted above, that some paleoanthropologists have considered them all to belong to the same species, our own, Homo sapiens. The point is therefore not that Craig is wrong, but that there are many viable options for Adam and Eve, and it’s difficult to say exactly which one is right. Perhaps this bolsters the compatibility of Adam and Eve with the scientific evidence to a higher degree than even Craig argues in his book.
Part 5: Lessons from the Evangelical Debate About Adam and Eve
As we saw in Part 3 of this review, in his book In Quest of the Historical Adam William Lane Craig is highly reticent about criticizing evolutionary science. That’s the case even when genetic and fossil evidence pose potent challenges to a mainstream evolutionary view. This reticence is common among evangelical elites. As soon as someone recommends challenging evolutionary science, many intellectual evangelicals immediately have a gut response warning that it’s dangerous to do this. We’re told that the history of science and faith is littered with examples of religious people trying to stand against science — especially evolution — only to get mowed down by its inexorable progress. Doesn’t questioning Darwin risk our looking foolish before the world? Isn’t it wiser to just shut up, get out of the way, and let evolutionary science speak without challenge?
William Lane Craig is to be commended for trying to see if a historical Adam and Eve existed, even as he tries to fit them within an evolutionary model. Perhaps Dr. Craig personally harbors doubts about evolution (I don’t really know), but if so, his book takes a rhetorical posture of silencing those doubts. His aim instead is to see if Adam and Eve can fit within an evolutionary view. This strategy has value in certain regards, but is it really required by the best science available? What if cautionary tales can be told of a different nature, leading to the opposite conclusion — that sometimes evangelicals prematurely latch on to what they think is “settled” evolutionary science, only to later find out that it was flawed? What if evangelicals are trying to conform to mainstream evolutionary ideas that are simply wrong? What if abandoning 2,000 years of orthodox beliefs, and capitulating to the evolutionary “consensus,” actually makes us look foolish because we’re letting go of important beliefs without having confirmed that science requires it?
It Started with a Christianity Today Article
In June 2011, Christianity Today (CT) published a cover story on “The Search for the Historical Adam.” However inadvertently, the article’s title (which sounds conspicuously similar to the title of Craig’s new book!) was misleading. The real purpose of the CT article was not to search for a historical Adam and Eve, but to highlight evangelical thinkers who fully accept modern evolutionary biology and reject traditional doctrines about a historical Adam and Eve. Filled with praise for Francis Collins — an evangelical celebrity scientist who made it big in the secular world — the article states:
Collins’s 2006 bestseller, The Language of God: A Scientist Presents Evidence for Belief — which so vexed those secularist critics — reported scientific indications that anatomically modern humans … originated with a population that numbered something like 10,000, not two individuals. Instead of the traditional belief in the specially created man and woman of Eden who were biologically different from all other creatures, Collins mused, might Genesis be presenting “a poetic and powerful allegory” about God endowing humanity with a spiritual and moral nature? “Both options are intellectually tenable,” he concluded.43
The basic argument is that modern day human genetic diversity is so great that it could not be explained by humans descending from a mere initial pair of two individuals. Many humans — thousands — would be necessary to generate a population with the genetic diversity that humans possess today. (There are other genetics-based arguments against an initial pair that Craig covers in his book but this has turned out to be the most important. Craig also does a good job in his book of showing that the Bible as a whole teaches that Adam and Eve were historical people, not merely allegorical.)
Four years prior to the CT article, Collins had founded the BioLogos Foundation with the purpose of promoting theistic evolution (or as some call it, evolutionary creationism), aiming to show that an evolutionary scientific viewpoint is fully correct and fully compatible with Christianity. The June 2011 CT article had high praise for BioLogos and its affiliated scientists, noting that “Dennis R. Venema, the BioLogos senior fellow for science and the biology chairman at Trinity Western University, is among the BioLogos writers who are not only advocating theistic evolution but also rethinking Adam.” Venema and then-BioLogos president Darrel Falk co-wrote a white paper on Adam and Eve, which CT quoted:
The BioLogos paper by Venema and Falk declares it more flatly: The human population, they say, “was definitely never as small as two …. Our species diverged as a population. The data are absolutely clear on that.”
CT provided endorsements for this from heavyweight theologians and biblical scholars suggesting that Adam may not be a “literal” historical figure. Old Testament scholar Bruce Waltke even seemingly expressed the view that science is more authoritative than Scripture:
“We have to go with the scientific evidence. I don’t think we can ignore it. I have full confidence in Scripture, but it does not represent what science represents.”
Other evangelical evolutionary scientists were quoted as saying things such as that Adam and Eve “do not fit the evidence,” or that although there was “wiggle room in the past” to believe in Adam and Eve, “human genome sequencing took that wiggle room away.”
Entering the Wider Culture
Three and a half months later, this in-house conversation among evangelicals spilled out into the mainstream media. A religion correspondent for NPR, Barbara Bradley Hagerty, participated in an NPR conversation with host Neal Conan, titled “Christians Divided Over Science Of Human Origins,” which retold the story:
CONAN: In particular, I was fascinated to read that some genetic evidence, DNA, was investigated by some of these Christian scholars and say, wait a minute, there’s no way you can have the diversity of human beings we have on the planet if you start with two people.
HAGERTY: Yeah, that’s right. They say now that we’ve mapped the human genome, it is clear that modern humans emerged from other primates way before the timeframe of Genesis, you know, like 100,000 years ago. And they say given the genetic variation, we can’t possibly get the original population to below about 10,000 people at any time in our evolutionary history.
And one scientist put it to me this way. He said there would have had to have been an astronomical mutation rate that produced all these new variants in this short amount of time, and those mutation rates simply are not possible. We’d have to — we would have mutated out of existence, he said. So it’s not possible.44
Daniel Harlow, a religion professor at Calvin College, was a guest on the show, and he articulated plainly the philosophical ideology behind the push to abandon traditional beliefs about Adam and Eve:
Well, science isn’t privileged, but if this world is God’s creation, then we have an obligation as bearers of the divine image to study the creation. Science uncovers facts about God’s world. It’s his world, right? And if we’re going to ignore what mainstream science says, then we have no right to expect people to listen to us when we preach the Gospel of Jesus Christ.
I think this anti-science, anti-evolution rhetoric typical of evangelicalism brings disrepute on the Christian faith, and it brings unnecessary shame upon the name of Jesus Christ.45
And there you have it: Harlow isn’t a scientist and although I’m sure he’s a smart guy, he probably is not equipped to evaluate the technical scientific details. Most likely, all he knows is that if “science” says that Adam and Eve could not have existed, then we must abandon this more than 2,000-year-old doctrine. To do otherwise is to be “anti-science” and “bring disrepute on the Christian faith” and “shame upon the name of Jesus Christ.” The push to abandon Adam and Eve was, in other words, driven by fears of looking bad before the world — not necessarily by compelling science.
This debate broke out before a wider church audience in 2017 when Venema and theologian Scot McKnight co-wrote Adam and the Genome. They sought to take these arguments to the masses. BioLogos heavily promoted the book, which argued that Adam and Eve are decisively refuted by the data — so much so that the case for rejecting the traditional doctrine is as scientifically strong as the heliocentric model of the solar system:
The sun is at the center of our solar system, humans evolved, and we evolved as a population.
Put most simply, DNA evidence indicates that humans descend from a large population because we, as a species, are so genetically diverse in the present day that a large ancestral population is needed to transmit that diversity to us. To date, every genetic analysis estimating ancestral population sizes has agreed that we descend from a population of thousands, not a single ancestral couple.46
By implication, if you doubt Venema’s and BioLogos’s conclusions on this, you’re as ignorant and backward as a geocentrist. Venema continued in the book by claiming that there is no one in the intelligent design camp capable of properly evaluating the data on Adam and Eve:
[T]here does not appear to be anyone in the antievolutionary camp at present with the necessary training to properly understand the evidence, much less offer a compelling case against it.47
Venema was wrong on multiple counts. Not only were there scientists in the ID camp capable of evaluating these arguments, but they were capable of showing that, despite Venema’s claims of heliocentric-level certainty, it was indeed possible to explain modern-day human genetic diversity as arising from an initial pair of individuals.
Venema and BioLogos Admit They Were Wrong
After the 2011 CT article, BioLogos-style arguments against Adam and Eve came under serious challenge. New voices in the discussion made different contributions ultimately showing that BioLogos was wrong.
First, there was biologist Ann Gauger, a senior fellow and senior research scientist with Discovery Institute. In the 2012 book Science and Human Origins, she looked at human genetic diversity in HLA genes, some of the most diverse genes in the human genome. According to Gauger, the great diversity of these genes “seemed to provide the strongest case from population genetics against two first parents.” Yet she found that this diversity could still be explained if we originated from an initial couple: “if it were true that we share thirty-two separate lineages of HLA-DRB1 with chimps, it would indeed cause difficulties for an original couple. But as we have seen, the data indicate that it is possible for us to have come from just two first parents.”48
Another voice that joined the conversation was that of Richard Buggs, an evolutionary geneticist at Queen Mary University London. After Adam and the Genome was published in 2017, Buggs engaged with Venema and other scientists on the BioLogos discussion forum, leading Venema to admit that the papers he had cited in his book had not actually addressed, and thus could not have refuted, the existence of an initial couple such as Adam and Eve.49 Buggs wrote:
Dennis, I have to say the conclusion I am coming to is that you made a mistake in your book. If so, I would have huge respect for you if you were willing to admit it, then we could all move on and discuss the interesting science of the other methods you have written about, and the work that Steven Schaffner is doing. We all make mistakes, and those of us active in research are very used to having them forcibly pointed out to us when we get back peer review comments on our manuscripts and grant proposals. It is never much fun to have them pointed out, but part of being a good scientist is being willing to correct our mistakes and move on.
The lengthy conversation continued into 2018, and Buggs later wrote:
You would do your readers a service if you wrote a blog to tell them now, as far as you are able, that present day genomic diversity in humans does not preclude a bottleneck in the human lineage between approx 700K and 7myr ago. I think you owe this to them, and to everyone who has taken the time to participate in this discussion.
The “bottleneck” he refers to is the idea that the human population was reduced to two individuals — the equivalent of our species being founded by Adam and Eve. Venema responded to Buggs, acknowledging that Buggs was correct and he was mistaken:
I’ve already agreed with this, and it’s been up there ^^ for weeks now. You’re welcome to publicize it as you wish. I no longer write in an official capacity for BioLogos, except by invitation from time to time. This means I’m just another commenter like you for the time being.
In a summary post at his Nature Ecology and Evolution blog in April 2018, Buggs noted the real issue was no longer whether Adam and Eve could have existed, but when:
To my mind, the question has now moved on from “Is an ‘Adam and Eve’ bottleneck inconsistent with human genetic diversity data?” to “At what timescale could an ‘Adam and Eve’ bottleneck be consistent with human genetic diversity data?”
Rewind to 2016
In fact, Ann Gauger had already embarked on a project with Ola Hössjer, a professor of mathematics at the University of Stockholm, to address that exact question: could Adam and Eve have existed, and if so, when? Gauger and Hössjer performed a comprehensive population genetics analysis of 1,000 human genomes to assess whether modern human genetic diversity could be accounted for if we descended from an initial pair granted “primordial diversity.” In a series of three papers published between 2016 and 2019 in the journal BIO-Complexity, they developed a population genetics model for investigating these questions. In their final paper, they showed that human genetic diversity can be accounted for even if humans are descended from a single pair of ancestors — e.g., Adam and Eve — that could have lived about 500,000 years ago. If additional evolutionary assumptions are questioned, they could have lived even more recently. Their BIO-Complexity papers are as follows:
- “Genetic Modeling of Human History, Part 1: Comparison of Common Descent and Unique Origin Approaches” (2016)
- “Genetic Modeling of Human History, Part 2: A Unique Origin Algorithm” (2016)
- “A Single-Couple Human Origin is Possible” (2019)
Ann Gauger has summarized much of this research at the website UniqueOriginResearch.com. Computational biologist and theistic evolutionist Joshua Swamidass also performed an analysis, posted at his online discussion forum, which found that Adam and Eve could have lived 495,000 years ago as our sole genetic progenitors.50
Thus, two robust analyses — one from Swamidass and the other from Hössjer and Gauger — concur that Adam and Eve could have lived about 500,000 years ago as our sole genetic progenitors. And again, that date could be sooner if we are willing to question additional evolutionary assumptions about human history.
As the exchange with Buggs reflected, Dennis Venema eventually admitted he was wrong. Swamidass also engaged privately with BioLogos and documented that they had “quietly deleted several articles from their website”51 that had claimed a historical Adam and Eve are incompatible with evolutionary science. Last year, BioLogos’s president, Deborah Haarsma, acknowledged BioLogos’s past mistakes on this topic, including that some BioLogos scientists “made premature claims…that evolutionary science and population genetics rule out scenarios with a recent universal human ancestor or with a de novo created ancestral pair.”52 She further wrote:
Over the years, we have removed old content from our website for many reasons, including articles…that overstated scientific claims, that unnecessarily excluded theological positions that are consistent with scientific evidence…we need to be honest when we overstate an argument.53
William Lane Craig reviews this saga in his book. He notes “six genetic features that have been put forward as allegedly incompatible with an original human couple” (p. 339) and finds that each one either does not actually address the existence of an initial pair or turns out to be flawed on closer analysis. Craig cites a 2019 blog post from Venema admitting he (Venema) was wrong on this crucial point. As Craig writes:
Venema came to acknowledge the failure of his arguments against a single-couple origin. “Based on some new simulations and some other published studies that we drew on, our group came to an agreement — that if an event like this had happened, we would be able to detect it if it happened more recently than 500,000 years ago. That was surprising to me, to be sure — I thought beforehand that an event like that would show up even further back in time.” Though he doubles down on the claim that “there is no positive evidence at all that such an event occurred,” that is a red herring, since no one has asserted that there is.pp. 353-354
Craig cites the work of various Christian biologists and other scientists in his book — Swamidass, Buggs, Gauger, and Hössjer, for example — and his analysis is detailed and carefully written. After affirming the existence of Adam and Eve, he concludes, “Challenges to this hypothesis from population genetics fail principally because we cannot rule out on the basis of genetic divergence exhibited by contemporary humans that our most recent common ancestors, situated more than 500 kya, are the sole genetic progenitors of the entire human race, whether past or present.” (p. 359)
Thus, I want to be clear that Craig isn’t part of the problem in this particular story and he should be commended for being willing to find room for Adam and Eve despite previous evolutionary claims to the contrary. But the implications of this saga for evangelical thinking on evolution are profound. Craig doesn’t discuss them, but they need to be stated.
Sometimes Accepting Evolution, Rather than Challenging It, Causes Trouble
Everyone makes mistakes — and Venema and BioLogos should be commended for modifying their positions when that was warranted by the evidence. Those mistakes can be forgiven and we can leave their particular details in the past. But if we leave the story there, then we miss its lesson.
The standard evolutionary account of human origins holds that our population has always been in the thousands and humanity did not descend from an initial pair. For years, theistic evolutionists (TEs) and evolutionary creationists (ECs) — specifically BioLogos and its affiliated scientists — forcefully promoted within the evangelical and wider Christian community this standard evolutionary view of human history. They argued that it eliminated the possibility that we were descended from Adam and Eve. These promotional efforts took the form of interviews with prominent news outlets along with conferences, books, and web articles. By the group’s own admission, BioLogos, with its philosophy of never challenging evolutionary science, made “premature claims” and “overstate[d] an argument” that “unnecessarily excluded theological positions.” Many evangelicals accepted their arguments that Adam and Eve did not exist.
Over the past decade, we’ve seen numerous instances of evangelical elites arguing — and buying into the argument — that the genetic data require us to reject 2,000+ year-old doctrines about the existence of a historical Adam and Eve. Those arguments have now turned out to be based upon bad science. The philosophy that it’s wrong for evangelicals to challenge evolutionary claims led many down a needless and most unfortunate path.
For those who have ears to hear it, the lesson is simple. Evangelical intellectuals in certain circles often assume that evolutionary science is correct, or at least should be treated as an immovable rock which should neither be questioned nor touched, lest one bring embarrassment on the church. But this assumption is false and the behaviors and fears that follow from it are unnecessary. Sometimes it’s claims made in the name of evolutionary science that are false. Even highly qualified, well-respected, and well-intentioned and well-credentialed evangelical scientists who promote TE and EC to the church can get things wrong.
Whether driven by a quest for certainty or a desire to please secular elites or something else, some evangelical leaders eagerly embraced ideas inimical to Christian orthodoxy, ideas that have not been established by good science. These leaders rejected important doctrines because of what was tantamount to junk science, and influenced many others to do likewise.
This story shows that it’s time to abandon the evangelical assumption that evolutionary claims are indisputable and must be accepted no matter what. It’s often better to live with some uncertainty and adopt a “wait and see” approach — pending careful analysis of the science — than to run headfirst into the arms of Darwin.
Unfortunately, some in the evangelical community have not learned from this experience. Instead, they seem intent upon repeating past mistakes. In the last section of my review of In Quest of the Historical Adam, I’ll consider two illustrations.
Part 6: Lessons Not Learned from the Evangelical Debate over Adam and Eve
In the previous installment of my review of William Lane Craig’s In Quest of the Historical Adam we saw that many evangelical intellectuals had accepted arguments that Adam and Eve could not have existed. These arguments, in particular the claim that human genetic diversity is too great to have been reduced to a single pair, were forcefully promoted by theistic evolutionists aka evolutionary creationists (TE/ECs) affiliated with BioLogos. Prominent among these critics was Dennis Venema, a biologist at Trinity Western University, who compared modern-day belief in Adam and Eve with adhering to the long-refuted geocentric model of the solar system. But the arguments turned out to be wrong, as even BioLogos and Venema now admit.
To his credit, William Lane Craig is among those evangelicals who have been willing to question arguments against a historical Adam and Eve. In his book he cites the work of Ann Gauger, Ola Hössjer, and Joshua Swamidass who performed analyses showing that humanity could have originated from a single pair at least 500,000 years ago. Gauger and Hössjer noted that Adam and Eve could have lived even more recently if additional evolutionary assumptions are questioned.
When I was reading the rhetoric used by evangelical elites who advocated abandoning a historical Adam and Eve, I was struck by how much of it seemed driven by fear — fear of looking foolish before the world because you challenged evolution and were shown to be wrong. As I discussed, the lesson from this story is that it should not be taboo for evangelicals to challenge evolutionary arguments. We need not live in fear that doing so is “anti-science” or will “bring disrepute on the Christian faith” or “shame upon the name of Jesus Christ” — as some evangelical elites have argued.
In this final installment of my review, we’ll see that unfortunately, some prominent Christians have not fully appreciated this lesson. They seem intent upon sticking with the evolutionary consensus, repeating past mistakes and embracing certain evolutionary ideas — despite a lack of compelling evidence. To be specific:
- BioLogos, Joshua Swamidass, and (sometimes) William Lane Craig now advocate a particular model of human origins where we are all descended from a population of hominids that evolved from a common ancestor we share with apes via standard evolutionary mechanisms — exactly as evolutionary theory proposes. Under this “Genealogical Adam and Eve” model Adam and Eve were historical people who may have been specially created, but their offspring interbred with those fully evolved hominids, eventually leading to us. This model is fundamentally evolutionary, but the evidence contradicts it or does not demand it.
- Craig in his book at times seems to disfavor the above model because it implies “bestial relations with nonhuman hominins.” He prefers to say that “No such appeal to interbreeding is necessary if we envision Adam and Eve as emerging from a hominin population that shared common ancestry with chimpanzees and other great apes.” (p. 378) This model is also challenged by the evidence.
- Whether Craig supports a standard evolutionary model where Adam and Eve are directly evolved from some common ancestor shared with apes (model 2 above), or the new model where Adam and Eve’s offspring interbred and intermixed with hominids that evolved from a common ancestor shared with apes (model 1 above), Craig is being driven by the idea that humans share a common ancestor with apes. In either case, he cites “broken” pseudogenes as evidence for human-ape common ancestry — relying on Dennis Venema as a primary source. The best science available also does not require this model to be true.
In the models above it seems that some Christians have not fully appreciated the lesson learned from evangelical debates over Adam and Eve: We need not fear that challenging an evolutionary model necessarily goes against good science. Rather than fear, let us be driven by a desire to find the truth. So let’s dig in.
Not Learning the Lesson on the Genealogical Adam and Eve Model
A July 2021 article from BioLogos now acknowledges the possibility of some version of a historical Adam and Eve. They say:
Options include…postulating that Adam and Eve were a special, historical pair who were indeed the ancestors of everyone alive today, but who were part of a larger population with whom their descendants could mate.54
Under this view, Adam and Eve were historical persons whose offspring interbred with a population of hominids which evolved from apelike ancestors. Note, however, that BioLogos distinguishes this view from what it calls the “common traditional” view where “Adam and Eve were created de novo” as our “‘sole progenitors’: they were the first two humans, and they alone gave rise to all other humans.”55 BioLogos seems to still disfavor this traditional view, instead preferring that Adam and Eve did exist but their offspring interbred with a large population of humans that evolved naturally from ape-like creatures. Thus, today BioLogos seemingly proposes that we are descended from both Adam and Eve as well as evolved hominids — and we share a common ancestor with living apes. This “Genealogical Adam and Eve” (GAE) model is definitely not the “common traditional” view.
The GAE model was elaborated by Joshua Swamidass in his 2019 book The Genealogical Adam and Eve.56 As we saw in part 4 of this review, William Lane Craig at times distances himself from this proposal because it implies “bestial” relations between the descendants of Adam and Eve with non-human hominins. However, in the final analysis he seems to allow the GAE model.
As a Christian I believe there are severe theological and scriptural problems with the GAE model, but this isn’t the place for such arguments. In any event, my main objections are scientific. Scientifically, the GAE model adopts a standard evolutionary view of human origins and says that if Adam and Eve were specially created then their offspring interbred and completely intermixed with a fully evolved population of hominids. We are the descendants of this large population. Because GAE adopts a standard evolutionary account of human origins, any scientific problems with such an account are inherited by the GAE model. Is the scientific evidence so compelling that we must accept this view?
As we saw in part 3 of this review, the fossil evidence for human evolution from apelike creatures is weak, and neo-Darwinian mechanisms face an overwhelming mathematical obstacle to account for the origin of complex human features such as our cognitive abilities. For these reasons, many aspects of the GAE model are scientifically problematic. If humans did not evolve from apelike creatures via standard evolutionary mechanisms, I see no compelling reason to adopt the GAE hypothesis.
Further, in part 5 of this review we saw that Gauger and Hössjer’s research — as well as Swamidass’s own modelling — show that if Adam and Eve lived far enough in the past, then modern human genetic diversity is compatible with an initial pair who were our sole ancestors. This eliminates any need to invoke thousands of evolutionary ancestors, which is a key feature of the GAE model.
So if the scientific evidence for human evolution is weak and the GAE model not even necessarily required by the evidence, then why is it supported by BioLogos, Swamidass, and (it seems in the end) William Lane Craig? These are complex questions and there are probably many reasons. But if I had to speculate, some of them are likely the same reasons that led people to wrongly reject a historical Adam and Eve in the first place.
The GAE model allows one to retain belief in a version (albeit a non-traditional one) of a historical Adam and Eve while still adopting a fully evolutionary model of human origins. This appeals to those who (as we saw in part 5 of this review) mistakenly believe that challenging evolution “brings disrepute on the Christian faith” and “unnecessary shame upon the name of Jesus Christ.” Paul Nelson has convincingly argued that the driving philosophy behind the GAE model is a prior commitment to methodological naturalism,57 the idea that when studying science, one is allowed to invoke only naturalistic forces and mechanisms. Perhaps not all GAE-proponents feel strongly about methodological naturalism, but they certainly seem to feel strongly about retaining an evolutionary model, for whatever reasons.
Yet if we care more about science and truth than about evolution, methodological naturalism, or worldly acceptance, then perhaps it is the GAE model that is “unnecessary.” I’m sure that many GAE proponents will disagree and say it is required by the science — but is the science really so clear that we must share a common ancestor with apes? We’ll get to that evidence shortly.
Whatever the reasons for adopting the Genealogical Adam and Eve model, as BioLogos admits, it is not the “common traditional” Adam and Eve. Under the GAE scenario, Adam and Eve are not the sole progenitors of humanity, and we are not descended only from them, but also from a large population of humans that fully evolved from apelike ancestors. Thus, Christians who adhere to a traditional Adam and Eve will have difficulty with the GAE model.
Not Learning the Lesson of Pseudogenes
Although Craig tells the story of the demise of BioLogos’s arguments against Adam and Eve, he still uses their arguments to support common ancestry. Citing Dennis Venema, Craig mentions pseudogenes as evidence for human-ape common ancestry:
One can, with Swamidass and Hössjer and Gauger, postulate instead a de novo creation of Adam and Eve. But then one faces a difficult dilemma. One must explain our genetic similarity to chimps either on the basis of repetitive divine use of a similar design plan or on the basis of considerable interbreeding with nonhumans. The first has difficulty explaining broken pseudogenes that we share with chimps… (p. 376, emphasis added)
As noted, Craig at times disfavors the GAE model because it implies bestiality between the descendants of Adam and Eve and non-human hominids. If he doesn’t accept the GAE model, and wants Adam and Eve to be our sole genetic progenitors, he seemingly has two choices: accept a version of Adam and Eve where they are miraculously created and we don’t share a common ancestor with apes, or view Adam and Eve as fully evolved hominins who did share a common ancestor with apes. Craig apparently prefers the latter option — common ancestry:
Some have appealed to interbreeding with other evolved hominin species in order to explain how Adam and Eve could have been de novo creations from inanimate material and yet their descendants bear such striking genetic similarity to chimpanzees, including broken pseudogenes that have ceased their original function (S. Joshua Swamidass, The Genealogical Adam and Eve: The Surprising Science of Universal Ancestry [Downers Grove, IL: IVP Academic, 2019]). Cf. Dennis Venema’s critique of Hössjer and Gauger’s de novo creationism on the grounds that the human genome is replete with evidence that we share common ancestors with other species, such as chimpanzees and gorillas (Dennis Venema, “Adam-Once More, with Feeling,” Jesus Creed (blog), November 4, 2019, http://www.patheos.com/blogs/jesuscreed/2019/11/04/adam -once-more-with-feeling). No such appeal to interbreeding is necessary if we envision Adam and Eve as emerging from a hominin population that shared common ancestry with chimpanzees and other great apes. Indeed, on the view proposed here, Adam and Eve could be our sole genetic progenitors, whose descendants never fell into bestial relations with nonhuman hominins or at least produced no descendants from such liaisons. (p. 378)
As we saw in part 4 of this review, the GAE model is designed to retain human-ape common ancestry and allow space for a miraculously created historical Adam and Eve, but it loses Adam and Eve as our “sole genetic progenitors.” The direct common ancestry model, which Craig seems to prefer above, views Adam and Eve as being descended from a common ancestor shared with apes, but does not allow them to be “miraculously created de novo.” Both models involve human-ape common ancestry, and although Craig isn’t clear which model he prefers, it is clear that he prefers some version of a human-chimp common ancestry model over a truly traditional model of Adam and Eve where they are our sole genetic ancestors, were miraculously created de novo, and don’t share common ancestry with apes.
Why is Craig willing to give up core aspects of a traditional Adam and Eve in favor of some model which requires human-ape common ancestry? The answer can be summed up in two words he uses in both quotes above: “broken pseudogenes.”
The logic goes as follows: Pseudogenes are broken genes which once had function but were inactivated by some mutation. God would never put broken DNA into two species in the same place, the argument goes. Therefore, if humans and apes share nonfunctional pseudogenes in the same location of our respective genomes, then we must have acquired those pseudogenes through some natural non-designed mechanism — namely, inheritance from a common ancestor.
Intelligent design is compatible with common ancestry, so in discussing this topic we’re not necessarily testing ID on the macro-scale. But on the small-scale the logic seems correct that broken DNA shared by two species is better explained by material evolutionary causes than by intelligent causation. But if pseudogenes aren’t broken non-functional junk DNA, then this raises the possibility that they are important functional parts of our genome. In that case, the reason we share “pseudogenic” DNA with apes isn’t common ancestry, but for functionally important reasons reflecting common design.
So are pseudogenes really “broken” and non-functional junk DNA? Well, what does the literature say?
A Rapidly Growing Trend in the Technical Literature: Pseudogene Function
In fact, the number of papers reporting extensive function for pseudogenes is impressive. Many prominent peer-reviewed scientific papers have said things like (my paraphrase), “We used to think pseudogenes were junk DNA, but this is just because we really didn’t have the technology to understand them. We still barely understand pseudogenes. But now that we’re developing methods of studying them, we’re discovering that functionality is quite common.” This means that it might be wiser to adopt a “wait and see” approach to pseudogenes, and not prematurely conclude they are just broken DNA reflecting our common ancestry with apes.
Consider the arguments of a BioEssays paper, “Processed pseudogenes: A substrate for evolutionary innovation,” just published in September 2021:
The implication of pseudogenes in biological processes including neurogenesis, inflammatory responses and cancer necessitates revisitation of the notion that pseudogenes are evolutionary ‘junk’. However, the extent of pseudogene activity remains poorly investigated, in part perhaps due the bias inherent to the term ‘pseudogene’, which presumes non-functionality. Furthermore, technical shortcomings have impeded unambiguous distinction of pseudogene activity from their near identical parental counterparts.58 [Emphasis added.]
The paper explains that although pseudogenes have been traditionally “labelled functionless en masse,” the truth is that “comparatively little is known” about them:
Following Ohno’s assumption that most duplicated genes are destined for degeneracy, Jacq and co-workers concluded that the identified 5S ribosomal RNA ‘pseudo’ genes were artefacts of evolution. These remarks provided the foundation for a framework that categorises apparently defective sequences with similarity to another gene as pseudogenes. The genomics revolution subsequently saw regions of the genome with pseudogene hallmarks labelled functionless en masse. Although pseudogenes are almost as numerous as protein-coding genes (14 767, of which, 72% are processed, 24% duplicated, 1.6% duplicated, 2.4% other, and 19 957, respectively), comparatively little is known about the contribution of pseudogenes to the evolution of the human genome.
Christian intellectuals who believe that pseudogenes are non-functional junk are adopting assumptions directly grown out of an evolutionary paradigm — and these are assumptions about an aspect of the genome that we actually know very little about. Neither Christians nor anyone else needs to fear that they are denying good science by anticipating function for pseudogenes, or at least by being cautious about jumping on the bandwagon that they are genetic “junk.”.
Many other authoritative papers argue similarly. A 2018 paper published in a Springer biochemistry journal comments:
For a long time, pseudogenes have been considered as “junk DNA” that inevitably arises as a result of ongoing evolutionary process. However, experimental data obtained during recent years indicate this understanding of the nature of pseudogenes is not entirely correct, and many pseudogenes perform important genetic functions. … pseudogenes are integral components of extensive regulatory networks of interacting genes.59
The paper continues:
Development of new generation DNA sequencing (NGS) has led to an unforeseen discovery of the pervasive transcription phenomenon. Although protein-encoding exon sequences represent only a small fraction of animal and plant genomes (<2% of human genome), the majority of them are transcribed. Therefore, it is not surprising that pseudogene RNAs (psRNAs) are significantly represented in the studied transcriptomes. Thus, about 10% of all identified (~15,000-18,000) human pseudogenes appear to be transcribed. According to available experimental data, transcribed pseudogenes may be divided into three groups: (1) universally transcribed, (2) non-specifically transcribed, and (3) transcribed in a strict tissue-specific manner. Universally expressed pseudogenes are related to housekeeping genes that usually have the largest number of pseudogenes. The second group of pseudogenes, in particular CYP4Z2P and derivatives of Oct-4, Connexin-43, and BRAF genes, are highly expressed in one or two tissue types, but demonstrate low expression levels in other tissues. Finally, strictly tissue-specific transcription was shown for ~150 human pseudogenes, including derivatives of the AURKA (kidneys) and RHOB (intestine) genes. The tissue-specific character of transcription suggests that these pseudogenes perform tissue specific functions. In general, the majority of transcribed pseudogenes have been detected in the testicles, whereas the muscle tissue has the least number of transcribed pseudogenes.
It’s important to appreciate what you just read: We already see evidence of function for about 10 percent of pseudogenes — something that evolutionists once thought impossible. But many pseudogenes are expressed only in specific tissues and at specific times. This suggests that it may be very difficult to detect the function and purpose of these pseudogenes. Why? Because they may be active just rarely during the human life cycle. You can’t keep a human being in a lab for a lifetime to see what’s going on in every tissue type. As the paper explains:
Although it has already been 40 years since the discovery of pseudogenes, investigation of these genomic components by modern methods is only at its beginning. [Emphasis added.]
Even so, as a paper in Annual Review of Genetics observed: “pseudogenes that have been suitably investigated often exhibit functional roles.”60 Likewise, a 2012 paper in RNA Biology states that “pseudogenes were long considered as junk genomic DNA” but “pseudogene regulation is widespread in eukaryotes.” The paper concludes that “the study of functional pseudogenes is just at the beginning” and predicts “more and more functional pseudogenes will be discovered as novel biological technologies are developed in the future.”61
These new technologies are already bearing fruit. The literature is full of papers reporting specific functions in sections of DNA previously labeled as “pseudogenes.”62 The ENCODE project reported over 850 human pseudogenes that are “transcribed and associated with active chromatin.”63 A paper in Molecular Biology and Evolution found that “656 human–macaque orthologous pseudogenes…are transcribed.”64 And a study of the human proteome published in Nature reported “more than 200 peptides that are encoded by 140 pseudogenes.”65
Mass-functionality for pseudogenes is no longer difficult to believe. They can yield functional proteins, functional RNA transcripts, or perform a function without producing any transcript. In RNA interference, a pseudogene yields an “anti-sense” RNA transcript which cannot produce a protein, but can bind with transcripts of protein-coding versions of the gene. When such binding occurs, the protein-coding transcript cannot be translated, reducing protein production.66 In target mimicry, small RNAs bind to a protein-coding mRNA transcript, inhibiting translation. If a pseudogene produces decoy mRNA transcripts which mimic the “target” sequence of the protein-coding counterparts, these small RNAs can bind to the pseudogene transcripts instead. This prevents inhibition of translation, increasing protein production.67 One of the papers quoted above lists multiple types of function for pseudogene RNA, which they call “psRNA”:
psRNAs participate in the regulation of parental gene expression at both transcriptional and translational levels. The sense strand of DNA serves as a template for the synthesis of sense mRNA (sRNA), whereas transcription of the antiparallel strand produces complementary antisense RNA (asRNA). As both sRNA and asRNA are synthesized during pseudogene transcription, we will further discuss the functional relevance of the pseudogene transcripts taking into account this structural difference.
Functions of sRNAs. Typically, sequences of pseudogene sRNAs only slightly differ from parental gene mRNAs. Due to the high similarity, they share miRNA-binding sites (miRNA response elements, MRE), whose binding to miRNAs ensures regulatory functions of these RNA molecules in both the nucleus and the cytoplasm. … The higher the pseudogene transcription activity, the higher the number of miRNA molecules that bind to its sRNA, which depletes their intracellular pool and reduces suppression of the parental gene expression, i.e., the ratio between the amounts of gene and pseudogene transcripts tunes gene expression….
Functions of asRNAs. Antisense transcription has been found in all studied living organisms. The NGS (next generation sequencing) data suggest that >70% RNAs in the mouse transcriptome overlap with complementary sequences, thus representing natural antisense transcripts. The same is true for the human transcriptome. In mice and humans, the majority of asRNAs are strictly conserved, which indicates their functional relevance, which has been experimentally confirmed. By now, many functions of asRNAs have been identified. asRNAs can affect their target genes both in cis and in trans. Some of these activities have been also observed for pseudogene asRNAs.
Pseudogene asRNAs in the formation of duplexes with parental gene sRNAs. Discovery of the involvement of pseudogene asRNAs in the inhibition of translation of parental gene mRNAs was one of the first indications of their functional role in living organisms. This mechanism is realized through the formation of RNA-RNA duplexes between highly homologous regions of the pseudogene asRNA and translated mRNA with subsequent suppression of the corresponding genes at the translation level….
Pseudogene asRNAs in the formation of short interfering RNAs (siRNAs). Pseudogene asRNAs participating in the formation of RNARNA duplexes may give rise to siRNAs. The structure and mechanism of action of regulatory siRNAs are similar to those of miRNAs….
Pseudogene asRNAs in the generation of piRNAs. Pseudogene-encoded RNAs that interact with PIWI proteins (piRNAs) were recently found among short noncoding RNAs in human and animal spermatozoa and germline cells….
Pseudogene asRNA in the regulation of transcription of target genes. By now, the role of lncRNAs in epigenetic genome modifications accompanied with the establishment of gene expression patterns in cells has been demonstrated and extensively studied. Similar properties were also observed for some pseudogene RNAs….68
Many other papers have warned against dismissing pseudogenes as mere junk. A 2012 paper in Science Signaling noted that although “pseudogenes have long been dismissed as junk DNA,” recent advances have established that “the DNA of a pseudogene, the RNA transcribed from a pseudogene, or the protein translated from a pseudogene can have multiple, diverse functions and that these functions can affect not only their parental genes but also unrelated genes.”69 Their homology to the protein-coding versions of the gene is necessary for this regulatory function, as “pseudogenes, due to their high-sequence homology, can act as legitimate bona fide microRNA competitors, thereby actively competing with their ancestral protein-coding genes for the same pool of microRNAs through sets of conserved MREs [microRNA response elements].”70 The Science Signalingpaper concludes that “pseudogenes have emerged as a previously unappreciated class of sophisticated modulators of gene expression.” A 2011 paper in the journal RNA concurs:
Pseudogenes have long been labeled as ‘junk’ DNA, failed copies of genes that arise during the evolution of genomes. However, recent results are challenging this moniker; indeed, some pseudogenes appear to harbor the potential to regulate their protein-coding cousins.71
As a 2013 paper in eLife states, “Pseudogenes are thought to be inactive gene sequences, but recent evidence of extensive pseudogene transcription raised the question of potential function.”72 Another paper in eLife from 2015 states, “Using a new bioinformatic method to analyze ribosome profiling data, we show that 40% of lncRNAs and pseudogene RNAs expressed in human cells are translated [into proteins].”73 The paper continues:
The experiments show that thousands of non-coding RNAs in the human genome are, in fact, translated. This is many more than anticipated and represents approximately 40% of the lncRNAs and pseudogene RNAs, and 35% of untranslated regions in messenger RNAs.
Sequence conservation can also imply pseudogene functionality even when a specific function has not yet been detected. A 2014 study in Proceedings of the National Academy of Sciences compared pseudogenes in humans, C. elegans, and fruit flies. It found direct evidence of function as well as conserved sequencing, suggesting function: “Overall, we identify a broad spectrum of biochemical activity for pseudogenes, with the majority in each organism exhibiting varying degrees of partial activity. In particular, we identify a consistent amount of transcription (∼15%) across all species, suggesting a uniform degradation process. Also, we see a uniform decay of pseudogene promoter activity relative to their coding counterparts and identify a number of pseudogenes with conserved upstream sequences and activity, hinting at potential regulatory roles.”74 A 2011 paper in Celllikewise infers functions in many pseudogenes: “Sequencing efforts have revealed ~19,000 pseudogenes in humans, many of which are transcribed and are often well conserved, suggesting that selective pressure to maintain pseudogenes exists.”75
One of the most profound and prominent statements on the subject came in a 2020 paper in Nature Reviews Genetics. This paper warned that pseudogene function is “Prematurely Dismissed” due to “dogma,” where “The dominant limitation in advancing the investigation of pseudogenes now lies in the trappings of the prevailing mindset that pseudogenic regions are intrinsically non-functional.” Instead the paper finds that “Where pseudogenes have been studied directly they are often found to have quantifiable biological roles.” Some of these functions are “protein-based,” meaning the pseudogene generates a functional protein. But other functions can be “RNA-based” or “DNA-based.” For example, evolutionists typically presume that a pseudogene that does not produce a protein can’t be functional. But the paper observes that pseudogenes that cannot be translated into a protein may still have a function through their RNA transcript:
Many pseudogenes contain a frequency of mutations that render them unlikely to be (or incapable of being) translated into proteins. However, such mutations do not necessarily preclude pseudogenes from performing a biological function.
A variety of other non-transcriptional functions are documented in the paper, including stabilizing chromosomes, mediating transcript-splicing, and regulating recombination. Thus, in many cases copy numbers of pseudogenes seem to have functional importance, where deviations from the normal genetic state cause disease. They predict: “It is expected that further links between human pseudogene polymorphisms and complex diseases will be identified in the coming years.”
The typical response from evolutionists would be that these examples are just isolated rare cases, and that the bulk of pseudogenes are nonetheless junk. The authors of the Nature Reviews Genetics paper — who give no indication of sympathy for intelligent design — are aware of this objection. They say the following in direct rebuttal to it:
The examples of pseudogene function elaborated on here should not imply that pseudogene functionality is likely to be confined to isolated instances. At least 15% of pseudogenes are transcriptionally active across three phyla, many of which are proximal to conserved regulatory regions. It is estimated that at least 63 new human-specific protein-coding genes were formed by retrotransposition since the divergence from other primates. Numerous ‘retrogenes’ continue to be recognized as functional protein-coding genes rather than pseudogenes across species. High-throughput mass spectrometry and ribosomal profiling approaches have identified hundreds of pseudogenes that are translated into peptides. Although the functions of these peptides remain to be experimentally determined, such examples illustrate the challenge in substantiating a gene–pseudogene dichotomy.
They continue: “As the abundance of such [non-coding-DNA] acquired functions does not appear to be an especially rare or isolated phenomenon, it would seem remiss to take the default perspective that processed pseudogenes are functionless. Instead, it is probable that pseudogene-containing regions of the genome harbour important biological functions that are yet to be revealed.”
However, at present, the authors note, “due in part to the experimental challenge of investigating their function and expression, pseudogenes are typically excluded from genome-wide functional screens and expression analyses.” In other words, one of the main reasons we aren’t finding function for pseudogenes is because we aren’t looking for it. One complication is that pseudogene transcription shows “cell-type specificity and dynamic expression” — meaning they may only be transcribed in particular places at particular times. This is all the more reason not to assume that lack of evidence for the function of a pseudogene is evidence that the pseudogene has no function! It very likely may be functional in a cell-type or a situation that we just haven’t properly investigated yet. As they put it, “The use of assays ill-suited to analysis of pseudogenes has arguably stymied elucidation of their biological roles.” But they are hopeful: “CRISPR-based approaches, carefully applied, have the potential to revolutionize our ability to dissect the functions of pseudogenes.”
The paper cautions that there are many instances where DNA that was dismissed as pseudogene junk was later found to be functional: “with a growing number of instances of pseudogene-annotated regions later found to exhibit biological function, there is an emerging risk that these regions of the genome are prematurely dismissed as pseudogenic and therefore regarded as void of function.”76
Pseudogene Mistakes of the Past
There is precedent for Christians prematurely dismissing pseudogenes as broken DNA, only to be later proven wrong. The same thing happened in earlier, high-profile situations. During the 2005 Kitzmiller v. Dover trial, leading theistic evolutionist biologist Kenneth Miller testified that the human beta-globin pseudogene is “broken” because “it has a series of molecular errors that render the gene non-functional.” Since humans, chimpanzees, and gorillas share “matching mistakes” in the pseudogene, he told the court, this “leads us to just one conclusion … that these three species share a common ancestor.”77 He was wrong. A 2013 study in Genome Biology and Evolution reported that the beta-globin pseudogene is functional.78
Humans have six copies of the beta-globin gene. Five produce beta-globin proteins, but the sixth, the pseudogene copy, has a premature stop codon that prevents proper translation. The researchers compared all six genes across humans and chimpanzees, and found the beta-globin pseudogene exhibits fewer differences than would be expected if it were non-functional and accumulating random mutations at a constant rate. This “conserved” sequence suggests the beta-globin pseudogene has a selectable function, making it less tolerant of mutations. The beta-globin pseudogene’s inability to produce a translatable RNA transcript does not preclude it from being functional. The researchers argue that the pseudogene works as an on/off switch, regulating expression of protein-coding beta-globin genes during embryonic development.
Relearning the Lesson of Pseudogenes
Despite all this evidence, most evolutionists still assume that pseudogenes are junk DNA. This remains the “consensus” view. Meanwhile, many Christian intellectuals don’t see the assumptions or appreciate the rapidly growing evidence of pseudogene function. They only see the consensus, and think we must not oppose it. But the trendline of the evidence shows that pseudogenes should not be assumed to be “broken” DNA. To summarize, there are many reasons to adopt a “wait and see” approach on pseudogenes:
- Pseudogene non-functionality is an assumption stemming from an evolutionary mindset, not a conclusion from careful studies of the evidence.
- In fact, pseudogenes have barely been studied — largely because technology has not yet been developed to study them. Our lack of technical ability to study pseudogenes stems directly from widespread evolutionary assumptions that they do nothing and that we shouldn’t waste our time trying to figure out what they do.
- Although entirely unanticipated under an evolutionary “junk” DNA mindset, many specific examples of pseudogene function have been found. In other cases pseudogene function has been inferred based upon biochemical activity of pseudogenic DNA or conservation of sequence.
- This evidence of pseudogene function is unsurprising because we know there are many ways that pseudogenes can have function: Pseudogenes can yield functional proteins, functional RNA transcripts, or perform a function without producing any transcript. Many pseudogene RNAs seem to have gene regulatory functions, often in an epigenetic context.
- We’re just at the beginning of developing technology to understand pseudogenes. Many pseudogenes may be active only in one tissue type or at certain stages of the life cycle, making their functions difficult to detect. So it’s not surprising that we don’t yet have an overwhelming number of examples of functional pseudogenes. But as we develop better technologies to study pseudogenes, functionality is showing itself to be more and more prevalent.
True, the precise functions of many pseudogenes remain unknown. For example, the Vitamin C “gulo” pseudogene, a unitary pseudogene shared by humans and many primates, is not yet known to have function (although it’s been argued that this pseudogene is active in utero). That is why it has become a popular argument against intelligent design among proponents of TE/EC. Prior to 2013, the same could have been said about the beta-globin pseudogene, now understood to have function.
Christian intellectuals who presume that pseudogenes are broken DNA are betting on a horse that has barely begun to run its race — and as the horse is starting to run we’re seeing that it’s not doing so well. Just as a paper in Nature Reviews Genetics cited above argued that pseudogene function is “Prematurely Dismissed,” some Christians are prematurely dismissing orthodox Christian doctrines. Even for those who don’t feel ready to endorse the view that pseudogenes are functional, at the very least an agnostic “wait and see” approach seems prudent, given the poverty of our knowledge and the trendline of the evidence.
Let’s talk about that trendline. Pseudogenes are just one type of DNA thought to be “junk.” Back in the 1990s and early 2000s, over 90 percent of the genome was commonly thought to be genetic junk — a view that is now rejected by most biologists. Intelligent design theorists predicted that much of junk DNA would turn out to have function. They were right: a revolution has largely taken over biological thinking. While there’s still a lot we don’t know about the genome, the trendline is strongly against the “junk” view. If you don’t believe me, look at the orange line in the top graph of this image from the journal Nature. It shows the rapid, even exponential rate at which functions are being discovered for non-coding genetic elements — which Nature says was “previously called junk DNA.”
Don’t bet on the wrong horse. Be cautious about throwing away millennia-old doctrines because you’re being told that the consensus demands you must believe that pseudogenes are “broken” genes inherited from our apelike ancestors. The consensus may say this but the evidence doesn’t. If you want to question or fully break with the consensus on pseudogene functionality, the evidence is there to support you. Challenging the consensus shouldn’t be done lightly and requires taking a risk based upon what you think the evidence says. But it was the right thing to do when it came rejecting evolutionary arguments against a historical Adam and Eve. Let’s be willing to take a risk on pseudogene functionality and follow the evidence where it is leading.
- Matthew Warren, “Diverse genome study upends understanding of how language evolved,” Nature (August 2, 2018), https://www.nature.com/articles/d41586-018-05859-7
- Writing in First Things, Craig proposes a model of human intellectual origins that seems to include a combination of God’s direct involvement and natural evolution: “We may imagine an initial population of hominins—animals that were like human beings in many respects but lacked the capacity for rational thought. Out of this population, God selected two and furnished them with intellects by renovating their brains and endowing them with rational souls. One can envision a regulatory genetic mutation, which effected a change in the functioning of the brain, resulting in significantly greater cognitive capacity. Such a transformation could equip the individuals with the neurological structure to support a rational soul. Thus the radical transition effected in the founding pair that lifted them to the human level plausibly involved both biological and spiritual renovation. Some behavioral outworkings of this transformation would be immediate, whereas others would emerge slowly through environmental niche construction and gene-cultural coevolution.” William Lane Craig, “The Historical Adam,” First Things (October, 2021), https://www.firstthings.com/article/2021/10/the-historical-adam
- See Francis Collins, Language of God: A Scientist Presents Evidence for Belief (Free Press, 2006), pp. 139-141.
- Michael D. Lemonick and Andrea Dorfman, “What Makes us Different?,” Time (October 1, 2006), http://content.time.com/time/magazine/article/0,9171,1541283,00.html.
- Yuval Noah Harari, Sapiens: A Brief History of Humankind (Harper, 2015).
- Charles T. Snowdon, “From Primate Communication to Human Language,” p. 224, in Tree of Origin: What Primate Behavior Can Tell Us About Human Social Evolution (Frans B.M. de Waal ed., Harvard University Press, 2001).
- Richard W. Byrne, “Social and Technical Forms of Primate Intelligence,” pp. 148-149, in Tree of Origin: What Primate Behavior Can Tell Us About Human Social Evolution (Frans B.M. de Waal ed., Harvard University Press, 2001).
- Hansell H. Stedman, Benjamin W. Kozyak, Anthony Nelson, Danielle M. Thesier, Leonard T. Su, David W. Low, Charles R. Bridges, Joseph B. Shrager, Nancy Minugh-Purvis & Marilyn A. Mitchell, “Myosin gene mutation correlates with anatomical changes in the human lineage,” Nature, 428: 415–418 (March 25, 2004).
- Joseph B. Verrengia, “Missing link found in gene mutation?,” NBC News (March 24, 2004), https://www.nbcnews.com/id/wbna4593822.
- Rick Durrett and Deena Schmidt, “Waiting for Two Mutations: With Applications to Regulatory Sequence Evolution and the Limits of Darwinian Evolution,” Genetics, 180: 1501-1509 (November 2008).
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- Alan Turner and Hannah O’Regan, “Zoogeography: Primate and Early Hominin Distribution and Migration Patterns,” inHandbook of Paleoanthropology: Principles, Methods, and Approaches, ed. Winfried Henke and Ian Tattersall, 2nd ed. (Heidelberg: Springer, 2015), 623-642.
- John Hawks, Keith Hunley, Sang-Hee Lee, and Milford Wolpoff, “Population Bottlenecks and Pleistocene Human Evolution,” Molecular Biology and Evolution, 17: 2-22 (2000).
- Daniel E. Lieberman, David R. Pilbeam, and Richard W. Wrangham, “The Transition from Australopithecus to Homo,” in Transitions in Prehistory: Essays in Honor of Ofer Bar-Yosef, eds. John J. Shea and Daniel E. Lieberman (Cambridge: Oxbow Books, 2009), 1.
- Ernst Mayr, What Makes Biology Unique?: Considerations on the Autonomy of a Scientific Discipline (Cambridge: Cambridge University Press, 2004), 198.
- “New study suggests big bang theory of human evolution” University of Michigan News Service, January 10, 2000, accessed July 10, 2016, http://www.umich.edu/~newsinfo/Releases/2000/Jan00/r011000b.html.
- Mirjana Roksandic, Predrag Radovi, Xiu-Jie Wu, and Christopher J. Bae, “Resolving the ‘muddle in the middle’: The case for Homobodoensis sp. nov.,” Evolutionary Anthropology (2021), DOI: 10.1002/EVAN.21929
- The University of Winnipeg, “New species of human ancestor named: Homo bodoensis,” ScienceDaily (October 28, 2021), https://www.sciencedaily.com/releases/2021/10/211028143648.htm
- John Hawks, “Significance of Neandertal and Denisovan Genomes in Human Evolution,” Annual Review of Anthropology, Vol. 42: 433-449 (2013) (“Neandertals and Denisovans were part of the biological species Homo sapiens.”).
- Aida Gómez-Robles, “Dental evolutionary rates and its implications for the Neanderthal–modern human divergence,” Science Advances,” Science Advances, 5: eaaw1268 (2019).
- Fred Spoor, Bernard Wood, and Frans Zonneveld, “Implications of early hominid labyrinthine morphology for evolution of human bipedal locomotion,” Nature 369 (June 23, 1994): 645-648.
- See Sigrid Hartwig-Scherer and Robert D. Martin, “Was ‘Lucy’ more human than her ‘child’? Observations on early hominid postcranial skeletons,” Journal of Human Evolution (1991) 21, 439-449.
- William R. Leonard, Marcia L. Robertson, and J. Josh Snodgrass, “Energetic Models of Human Nutritional Evolution,” in Evolution of the Human Diet: The Known, the Unknown, and the Unknowable, ed. Peter S. Ungar (Oxford, UK: Oxford University Press, 2007), 344-359.
- Jan Jelínek, “Homo erectus or Homo sapiens?” In Recent Advances in Primatology, Volume Three: Evolution, edited by D.J. Chivers and K.A. Joysey, 419-429. London: Academic Press, 1978; Emilio Aguirre, “Homo erectus and Homo sapiens: One or More Species?” In 100 Years of Pithecanthropus: The Homo erectus Problem 171 Courier Forschungsinstitut Seckenberg, edited by Jens Lorenz, 333-339. Frankfurt: Courier Forschungsinstitut Senckenberg, 1994; Milford H. Wolpoff, Alan G. Thorne, Jan Jelínek, and Zhang Yinyun. “The Case for Sinking Homo erectus: 100 Years of Pithecanthropus is Enough!” In 100 Years of Pithecanthropus: The Homo erectus Problem 171 Courier Forschungsinstitut Seckenberg, edited by Jens Lorenz, 341-361. Frankfurt: Courier Forschungsinstitut Senckenberg, 1994; Eric Delson, “One skull does not a species make.” Nature 389 (October 2, 1997): 445-46; John Hawks, Keith Hunley, Sang-Hee Lee, and Milford Wolpoff. “Population Bottlenecks and Pleistocene Human Evolution.” Journal of Molecular Biology and Evolution 17 (2000): 2-22.
- Donald C. Johanson and Maitland Edey, Lucy: The Beginnings of Humankind (New York: Simon & Schuster, 1981).
- See S. Molnar, Races, types, and ethnic groups: the problem of human variation, p. 57 (1975); S. Molnar, Human Variation Races Types and Ethnic Groups, p. 65 (2nd ed., 1983); C. G. Conroy, et. al., “Endocranial Capacity in an Early Hominid Cranium from Sterkfontein, South Africa,” Science, 280:1730-1731 (1998); Bernard Wood and Mark Collard, “The Human Genus,” Science, 284:65-71 (1999).
- Bernard Wood and Mark Collard, “The Human Genus,” Science, 284 (April 2, 1999): 65-71.
- Terrance W. Deacon, “Problems of Ontogeny and Phylogeny in Brain-Size Evolution,” International Journal of Primatology 11 (1990): 237-82. See also Terrence W. Deacon, “What makes the human brain different?,” Annual Review of Anthropology 26 (1997): 337-57; Stephen Molnar, Human Variation: Races, Types, and Ethnic Groups, 5th ed. (Upper Saddle River: Prentice Hall, 2002), 189 (“The size of the brain is but one of the factors related to human intelligence”).
- Terrance W. Deacon, “Problems of Ontogeny and Phylogeny in Brain-Size Evolution,” International Journal of Primatology, 11 (1990): 237–82. See also Terrence W. Deacon, “What makes the human brain different?,” Annual Review of Anthropology, 26 (1997): 337–57.
- Stephen Molnar, Human Variation: Races, Types, and Ethnic Groups, 5th ed. (Upper Saddle River: Prentice Hall, 2002), 189.
- Christoph Koch, “Does Brain Size Matter?,” Scientific American Mind (January/February, 2016), 22-25.
- C. B. Stringer, “Evolution of Early Humans,” in Cambridge Encyclopedia of Human Evolution, 241.
- For example, Craig infers from Neanderthal hunting strategies that it was capable of “extremely careful planning, coordination, and discussion” (p. 294, quoting Thieme, 2007). On this point he is probably correct, but we can we not make similar inferences based upon erectus migration strategies?
- Jørn Madsen, “Who Was Homo erectus,” Science Illustrated (July/August 2012): 23.
- Quoted in Nicola Davis, “Homo erectus may have been a sailor – and able to speak,” The Guardian (February 19, 2018), https://www.theguardian.com/science/2018/feb/20/homo-erectus-may-have-been-a-sailor-and-able-to-speak.
- Quoted in Nicola Davis, “Homo erectus may have been a sailor – and able to speak,” The Guardian (February 19, 2018), https://www.theguardian.com/science/2018/feb/20/homo-erectus-may-have-been-a-sailor-and-able-to-speak.
- Daniel Everett, “Did Homo erectus speak?,” Aeon, February 28, 2018, https://aeon.co/essays/tools-and-voyages-suggest-that-homo-erectus-invented-language.
- Mark Collard and Bernard Wood, “How reliable are human phylogenetic hypotheses?,” Proceedings of the National Academy of Sciences (USA), 97 (April 25, 2000): 5003–06.
- William R. Leonard and Marcia L. Robertson, “Comparative Primate Energetics and Hominid Evolution,” American Journal of Physical Anthropology 102 (February, 1997): 265-81. See also Leslie C. Aiello and Jonathan C. K. Wells, “Energetics and the Evolution of the Genus Homo,” Annual Review of Anthropology 31 (2002): 323-38.
- Aiello and Wells, “Energetics and the Evolution of the Genus Homo” (emphases added).
- William R. Leonard, J. Josh Snodgrass, and Marcia L. Robertson, “Effects of Brain Evolution on Human Nutrition and Metabolism,” Annual Review of Nutrition 27 (2007): 311-27; William R. Leonard, Size Counts: Evolutionary Perspectives on Physical Activity and Body Size From Early Hominids to Modern Humans,” Journal of Physical Activity and Health 7 (2010): S284-98; Leonard et al., “Energetics and the Evolution of Brain Size in Early Homo.”
- Leslie C. Aiello and Jonathan C. K. Wells, “Energetics and the evolution of the genus Homo,” Annual Review of Anthropology(2002), 31:323-338.
- Richard Ostling, “The Search for the Historical Adam,” Christianity Today (June 3, 2011), https://www.christianitytoday.com/ct/2011/june/historicaladam.html
- “Christians Divided Over Science Of Human Origins,” NPR (September 22, 2011), https://www.npr.org/2011/09/22/140710361/christians-divided-over-science-of-human-origins
- Ibid. Emphasis added.
- Dennis Venema and Scot McKnight, Adam and the Genome: Reading Scripture after Genetic Science (Brazos Press, 2017), p. 55.
- Dennis Venema and Scot McKnight, Adam and the Genome: Reading Scripture after Genetic Science (Brazos Press, 2017), p. 65.
- Ann Gauger, “The Science of Adam and Eve,” in Science and Human Origins, by Ann Gauger, Douglas Axe, and Casey Luskin (Discovery Institute Press, 2012), p. 120.
- This story is told at “Adam and the Genome and Citation Bluffing,” Evolution News (February 7, 2018), https://evolutionnews.org/2018/02/adam-and-the-genome-and-citation-bluffing/
- S. Joshua Swamidass, “Heliocentric Certainty Against a Bottleneck of Two?,” Peaceful Science (first post on December 29, 2017), https://discourse.peacefulscience.org/t/heliocentric-certainty-against-a-bottleneck-of-two/61
- S. Joshua Swamidass, “A U-Turn on Adam and Eve,” Peaceful Science (August 30, 2021), https://peacefulscience.org/articles/biologos-uturn-adam-eve-position/
- See editorial note in Thomas H. McCall, “Will The Real Adam Please Stand Up? The Surprising Theology Of Universal Ancestry,” BioLogos (March 23, 2020), https://biologos.org/series/book-review-the-genealogical-adam-and-eve/articles/will-the-real-adam-please-stand-up-the-surprising-theology-of-universal-ancestry (emphasis added).
- Deborah Haarsma, “Truth-Seeking in Science,” BioLogos (January 10, 2020), https://biologos.org/articles/truth-seeking-in-science
- Stephen Schaffner, “What Genetics Says About Adam and Eve,” BioLogos (July 11, 2021), https://biologos.org/articles/what-genetics-say-about-adam-and-eve.
- “Were Adam and Eve historical figures?,” BioLogos, https://biologos.org/common-questions/were-adam-and-eve-historical-figures/ (accessed October 26, 2021). Biologos notes that this “common traditional” view might be rejected if “the results of scientific inquiry … conflict with traditional interpretations.”
- S. Joshua Swamidass, The Genealogical Adam and Eve: The Surprising Science of Universal Ancestry (IVP Academic, 2019).
- See Paul Nelson, “Which Game? Whose Rules?” (August 24, 2020), https://henrycenter.tiu.edu/2020/08/which-game-whose-rules/; Paul Nelson, “Trapped in the Naturalistic Parabola” (June 17, 2020), https://evolutionnews.org/2020/06/trapped-in-the-naturalistic-parabola/; Paul Nelson, “Nelson: Parabolas and Methodological Naturalism (Again)” (June, 2020),https://discourse.peacefulscience.org/t/nelson-parabolas-and-methodological-naturalism-again/10956/2.
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