The Historicity of Adam : A Biblical Defence (Collated With Scientific Articles)
Contemporary Denial of Historicity of Adam
Many critics declare that the church’s teaching of the historicity Adam has been discredited by recent advancements in science. It is purportedly impossible to reconcile the doctrine of Adam as a recent historical individual with fossils remains of ancient hominids pointing to a long process of evolution of humans who share a common ancestry with apes. Furthermore, recent studies of population genetics conclude that a historical pair (Adam and Eve) is insufficient to account for the genetic variations in DNA sequences found in the present human race.
A corollary of denial of the historicity of Adam is denial of the doctrine of original sin. Without a historical Adam there would be no historical Fall in which Adam suffered a fractured relationship and lost his power of communion with God, with the consequence of sin and death spreading to all humanity. An evolutionary view of ‘Adam’ as a group of ancient hominids would consider moral predicaments [a preferred term since it is a more neutral term than ‘sin’] and death of the human race as a built-in necessity for biological and moral evolution. Richard Gaffin aptly captures this logic of abandonment of the historicity of Adam,
Evolution excludes believing the Bible’s claim that sin entered human history at a point after its beginning. Evolution, in other words, precludes the fall as taught in Scripture. It replaces the historical before-and-after of creation and fall with their side-by-side inseparability. Sin is not a matter of human fallenness but of human givenness. Whatever else being human may mean, it entails being sinful, or at least being naturally and inalterably disposed of sin.
[Peter] Enns adopts a “crucial theological distinction” from an article by George L. Murphy, the distinction between “original sin” and “sin of origin.” The former is the Augustinian notion, alleged to be no longer viable either historically or theologically. “The latter affirms the absolute inevitability of sin that affects every human being from their beginnings, from birth.” The “self-evident reality of repeated, relentless sin remains an unalterable and existential fact of human existence.
Gaffin argues that Enns “sin of origin” would empty the work of Christ salvation of its meaning and significance,
But then Paul would be wrong not only in declaring that “the wages of sin is death” (Rom. 6:23); he is wrong in declaring that the salvation entails resurrection to a new body in the Christ the second Adam (Rom. 4:25 and 1 Cor. 15:3-4, 17). If Evolution excludes the teaching on the first things in the historical Adam, it also excludes the last things in the Second historical Adam. The redemptive historical correlation between Adam and Christ, their unparalleled and irreplaceable analogical roles as determinative head and origin of their respective fallen and redeemed race is emptied of meaning and significance. [See J.P. Versteeg, Adam in the New Testament: Mere Teaching Model or First Historical Man? 2nd ed. (Presb & Reformed 2012), pp. xiii-xiv].
Peter Enns feels compelled in his reading of the evidence for the theory of human evolution to abandon belief in the historical Adam. However, such a capitulation is unnecessary. In reality, the primary evidence for human evolution in the field of paleoanthropology and population genetics are more contestable than what critics are willing to admit. Scholars (whether atheists or theists) have reasons to be honest about the tentativeness of their disputed theories of human evolution as evidenced by the ongoing debates in the learned journals.
The debate becomes even more complex when critics try to relate these tentative findings to Biblical history of human origins. Any adequate treatment would require expertise in historical criticism and Biblical hermeneutics informed by the latest developments across scientific disciplines like geology, paleoanthropology and molecular biology. No wonder the debate swirls interminably. The dispute easily collapses into an academic black hole, sucking up all the intellectual energy of the disputants without yielding much (if any) light. Joining the fray would suggest an intellectual ambition befitting of polymaths, although the hazardous journey into the black hole is inevitable.
An honest disclosure of my intellectual position is in order. I am a Christian who is convinced that the Bible is accurate in both matters of history and salvation. I hold to an “old-age Earth” and maintain the traditional church teaching of Adam and Eve as a historical pair from whom the whole human race is descended, while keeping an open mind about the possibility of pre-Adamic hominids (with the caveat that there is discontinuity and qualitative difference between these hominids and Adam). However, I believe one can hold to these beliefs without sacrificing one’s intellectual integrity even as one is fully aware of strong challenges arising from recent discoveries of ancient human fossils and advancements in population genetics. Admittedly, I am not approaching the controversy with religious neutrality, but so does everyone since any inquiry can proceed only with some form of prescientific commitments (whether theistic or atheistic). Truth be told, the theory of Evolution is subject to the limits of empirical underdetermination (Pierre Duhem & W.V.O. Quine) and is at best an inference to the best explanation in contrast to experimentally confirmed theories of laboratory physics.
Prima Facie Biblical Evidence for the Historicity of Adam
This article shall only attempt a modest theological foray into the dispute [For critical analysis of scientific evidence for human evolution, see bibliography at the end of the article].
We begin with prima facie evidence from the Bible which consistently teaches Adam as a historical individual:
1. Genesis 1-3 is presented as a historical narrative with succession of dated historical events and people with precise lifespans. Adam must be as real as Abraham.
2. 1Chronicles, one of ancient Israel’s official historical records includes Adam. Likewise, Luke the historian traces human descent from Adam to Jesus. Presumably, both the Chronicler and Luke assume their readers will take Adam as an individual like the other individuals (including Christ) in their genealogies.
3. Hosea 6:7 reads as “Like Adam they transgress the Covenant.” Adam is here referred to as an individual. Reading Adam generically (as a race; KJV- like men) amounts to substituting an explicit reference to an individual who can be held accountable for breaking a covenant agreement with a vague reference to an unknown race with a hypothetical covenant with God.
4. In Matt. 19:3-9, Jesus’ settlement of the divorce dispute is premised on Adam and Eve as a historical pair.
5. Paul’s theological argument of origin of sin in Adam and salvation in Christ in Romans 5 requires both Adam and Christ to be equally historical to be logically consistent and cogent. The same requirement of the historical Adam applies in Paul’s ethical imperative in 1 Tim 2:12-14.
6. Jude 14 listed Enoch as the seventh from Adam. The surface reading presents a historical listing, regardless of the dispute over the literary genre (pseudepigrapha) of the book of Enoch.
These Biblical references cumulatively constitute a compelling case for Adam to be a historical individual. However, in this short article I shall only focus on no. 5 to demonstrate how the veracity of a historical Adam is indispensable to the fundamental structure of biblical theology embodied in Paul’s teaching of salvation in Christ.
The Hermeneutics of Apostle Paul
Paul deploys an analogical framework (or typological framework, to use a Biblical term) to compare and contrast the fall in Adam and redemption in Christ in Romans 5:12-21. Paul uses the Greek word “tupos” to describe how Adam is the pattern or image of Christ. That is to say, Adam is a prophetic anticipation or prefiguration of Christ. Critical scholars reject typology as an arbitrary hermeneutical device, but it is only reading the Bible on its own terms. A responsibly use of typology would include the following hermeneutical delimitations (suggested by L. Goppelt and E. E. Ellis):
First, a type is not to be thought of apart from God’s saving activity in (redemptive) history. Accordingly, the types or prefiguration used in the New Testament are not generic ideas, but actual events or persons in Old Testament history.
Second, typology is the tracing of the constant principles of God’s working in history where past history is taken up more fully and perfectly in the Gospel events. In the words of Paul in Colossians, we move from shadow to substance (Colossians 2:17) as we move from Old Testament type to New Testament antitype.
Third, the relation between type and antitype must be understood within the framework of divine plan or divine dispensation of salvation. Since typology is the theological interpretation of Old Testament history, the correspondence or analogy must be both historical (with regard to the events) and theological (with regard to God’s constancy in his historical acts).
To conclude, a type is “an event, a series of circumstances or an aspect of the life of an individual or of the nation, which finds a parallel and a deeper realization in the incarnate life of our Lord, in His provision for the needs of man, or in His judgment and future reign (Francis Foulkes). The antitype not only fulfills the type, it also exceeds the type in scope and significance. For example, God’s new exodus or salvation in Christ exceeds the scope and spiritual significance of Moses exodus. Christ work of redeeming humanity exceeds the consequences of Adam’s sin and death upon humanity. There is both analogy and disparity in the relationship between type and antitype.
Theological Argument in Romans 5:12-21
We now apply this typological framework to the relationship between Adam and Christ. I shall refer extensively to J.P. Versteeg, Adam in the New Testament.
Paul highlights the fact that it was through an individual or ‘one man’ that ‘sin entered the world’. The relationship between this sin of Adam and the consequence of universal death of all humanity is neatly summarized by Colin Kruse, “The primary cause is Adam’s disobedience, through which death first entered the world, and the secondary cause is the sin of disobedience of all human beings, who likewise bring death upon themselves.”
Paul highlights the correspondence between Adam and Christ, based on the principle that the act of obedience for Christ and the act of disobedience for Adam are decisive for all who belong to them. He describes Adam as a type of the one who is to come (Christ), although with contrasting effects –Adam’s act was a trespass (wrongdoing) that brings condemnation or death to many (the old humanity), but Christ’s act has greater consequences since by his act he brings justification or a gift of life graciously given to many (the new humanity).
Versteeg carefully spells out the logic of Paul’s argument based on Adam as a historical individual:
the disobedience of Adam is not merely illustrative for all other men but is determinative for all other men. It has been correctly pointed out that the word “first” (sinner) does not occur in the whole of Romans 5. Here Adam is characterized as “the one” who occupies a unique position, by which his act of disobedience is of decisive significance for all who belong to him. “Whether someone is the first to sin or sins as the head of a community and so opens the door for the consequence of sin, death, upon his descendants are two different matters.”
Incidentally, with the words “from Adam to Moses” Paul is obviously thinking of a fixed portion of time, a given historical period. Adam stands at the beginning of that period, Moses at the end. As surely as a historical terminus is in view in the case of Moses, a historical starting point is in view in the case of Adam. It is inconceivable that for a fixed portion of time that is clearly intended as a historical period, Paul would have in mind a historical terminus (Moses) and not a historical starting point.
Verse 19 also points further in the direction of representation. Here the verbs usually translated “were made” and “will be made” can also be rendered by “were constituted” and “will be constituted.”
In the entire section preceding verse 19, “justification” and “righteousness” are spoken of only in the sense of a gift imputed by God. Likewise, being constituted “sinners” in the sense of being reckoned as sinners connects with what is said in the preceding verses about the decisive significance of the sin of Adam for all who belong to him. If we ask ourselves how we are to conceive of this “being constituted,” we can say with Ridderbos: “Again everything comes down to the fact of the many being represented in the one man Adam and the one man Christ. (pp. 23-27)
1 Corinthians 15:22, 45
As in Romans 5 so also in 1 Corinthians 15, Adam and Christ are spoken of as representative heads of all who belong to them. That is to say, both of them are not only historical; they are also public figures given the decisive significance of “the one over the many” is especially evident in how Paul applies the idea of Christ as “firstfruits” of those who are asleep.
Gordon Fee explains how in v. 20 Paul assured the Corinthians that since Christ’s resurrection as “firstfruits” effected an inevitable reversal of the process of death that began with Adam.
“In saying that “all die in Adam,” Paul means that this common lot of our humanity is the result of our being ‘in Adam,” that is, being born of his race and thereby involved in the sin and death that proceeded from him (cf. Rom. 5:12–14, 18–19). In saying that “in Christ all will be made alive,” Paul means that those who are “in Christ,” those who have entered the new humanity through grace by means of his death and resurrection, will just as certainly “be made alive” ; they will be raised from the dead into the shared life of the risen One. Thus Christ is the firstfruits; he is God’s pledge that all who are his will be raised from the dead. The inevitable process of death begun in Adam will be reversed by the equally inevitable process of “bringing to life” begun in Christ (Commentary on 1 Corinthians NICNT).
Paul returns to the theme in verse 45 where he affirms again that Adam and Christ are representative heads of all who belong to them. The “earthly” Adam is determinative of those who are “earthly” while the “heavenly” Christ is determinative for those who are “heavenly”.
Versteeg presses home his contention that Adam is an individual representative head and not a general pedagogical symbol:
We can say the same thing about the references to Adam in 1Corinthians 15 that we said in connection with Romans 5:12-21. Where Adam is referred to as a representative head, it is not possible to apply to him the qualification “teaching model.” That qualification cannot do justice to the unique position of Adam.
It is striking that in verse 45a, where Paul refers to Adam, he expressly calls Adam “the first man, Adam”… These additions make clear that for Paul, Adam was not merely the model of man” but a particular man with a particular place in the history of humanity.
If in antithesis to Adam as a historical person, Adam is to be spoken of as a teaching model that in fact involves a particular view of sin. If Adam only lets us see what is characteristic of everyone, because Adam is man in general so that the sin of Adam is also the sin of man in general, and if on the other hand Adam may no longer be regarded as the one man through whom sin has come into the world, it is apparent that in a certain sense sin belongs to man as such. Sin has thus become a given “next to” creation. Consequently, in Romans 5:12 Paul does not say how sin invaded creation but only that there is sin and that sin is always an affair of man. With Bakker, however, one has to say that it makes a good deal of difference whether in Romans 5 Paul expresses himself in terms of a historical framework that does service as clothing for the supratemproal truth that the good creation is from God and sin an affair of ours, or in Romans 5 Paul intends rather to say how sin has invaded the good creation of God. The concept ‘teaching model” cannot do justice to the latter. If Adam were only a teaching model, he would only be an illustration of man in whom sin is inherent. The concept “teaching model” eliminates the “one after the other” of creation and fall, and only leaves room for the “next after the other” of creation and fall, and only leaves room for the “next to each other” of creation and sin (p. 62).
Denial of Historical Adam Undermines the Doctrine of Redemption
It is obvious by now that denying Adam as an historical individual changes one’s understanding of sin and the nature of salvation. If sin is merely a biological necessity or moral limitation, humanity only needs betterment through education; but if sin is an act of moral disobedience or spiritual rebellion, humanity desperately needs the atoning salvation of Christ. Veersteg explains,
Adam as a teaching model in antithesis to Adam as a historical person involves a particular view of redemption. As we have seen, in Romans 5:12-21 Paul contrasts the redeeming work of Christ as the one act of obedience with the sin of Adam as the one act of disobedience. Now in Romans 5, all sorts of words are used for the sin of Adam which indicate clearly the guilty character of that sin. The sin of Adam was a “trespass” and a “disobedience.” The redeeming work of Christ, which stands in opposition to this sin of Adam, therefore bears the character of atonement for guilt.” (pp. 64-65).
Christian salvation is premised on the historical reality of an irruption of sin into the human race (or the Fall of Adam) and the historical Christ in his work of salvation. Obviously, no Christian would deny the historical reality of Christ. However, there are Christians who willingly abandon the teaching of the historical Adam in order to be “up to date” with the latest views of human evolution even though this requires them to dispense with the traditional church teaching that sin entered the world through a first man. These Christians also qualify sin with caveats like “Adam was existentially sinful but not spiritually guilty” as ‘sin’ is viewed as embedded in the evolutionary process of humanity. Original sin becomes something to do with actualization of human freedom or euphemistically described as an “upward Fall”, or “an ascent in moral awareness”. ‘Sin’ becomes basically an unavoidable disturbance or even catalyst in the evolutionary process. Theologically, “Adam” is no longer a historical person, but a “teaching model” embodying a timeless truth about “everyman”.
Versteeg points to a salutary lesson drawn from an earlier debate between Rudolph Bultmann and Karl Barth.
If the figure of Adam becomes an idea, Christ, too, threatens to become an idea. If the significance of Adam consists entirely in the fact that he is the image of man in his sinfulness and disobedience before God, it is only step further to maintaining that the significance of Christ likewise consists entirely in the fact that he is the image of man as God intends him to be and as he someday will be…The humanity of Christ receives all the emphasis, while the preaching of Scripture that Christ is not only man but also in a unique sense the son of God recedes into the background.
As the first historical man and head of humanity, Adam is not mentioned merely in passing in the New Testament. The redemptive-historical correlation between Adam and Christ determines the framework in which – particularly for Paul – the redemptive work of Christ has its place. That work of redemption can no longer be confessed according to the meaning of Scripture, if it is divorced from the framework in which it stands there. Whoever divorces the work of redemption from the framework in which it stands in Scripture no longer allows the Word to function as the norm that determines everything. There has been no temptation down through the centuries that theology has been more exposed to than this temptation. There is no danger that theology has more to fear than this danger. (pp. 64-67)
In the words of Richard Gaffin, “Evolution excludes biblical teaching on “last things” no less than on “first things.” The two, as we will presently note further, are inextricably tethered to each other. The Bible’s eschatology is no more compatible with evolution than its protology.” (pp. xiv-xix)
Tentative Science and Christian Certitude of Salvation
Disputes over complex theories of human evolution are to be expected. Christians should keep abreast with the latest developments of the scientific enterprise, even though they are mindful of the fact that the human fossil remains are both fragmentary and subject to interpretations that are essentially contestable. Likewise, any integration of faith and science must remain tentative and subject to future refinements.
Finally, Paul demonstrates in Romans 5 how Christian salvation unfolds through an inexorable sequence historical events – The Fall of an historical Adam brings forth universal death for humanity; the historical Christ redeems fallen humanity; the historical resurrection confirms the efficacy of Christ’s work of salvation and represents the firstfruits (proleptic anticipation) of the final resurrection of redeemed humanity in Christ. Every part of this chain must be an actual historical event for Paul’s carefully constructed argument to be valid. If the historicity of resurrection of Christ is a non-negotiable tenet of Christian faith, likewise the historicity of Adam and the Fall is also a non-negotiable tenet of faith. As such, Christians are only following a fundamental theological insight of Paul when they confess, “As we believe in the historical Christ, we also believe in the historical Adam.”
For Further Reading:
A. Opposing views on Evolution, Creation and Historical Adam
1. Matthew Barrett et.al., Four Views on the Historical Adam (Zondervan 2013).
2. Peter Enns, The Evolution of Adam (Brazos 2012). [Given human evolution, no historical Adam]
3. C. John Collins, Did Adam and Eve Really Exist? (Crossway 2011). [Biblical Hermeneutics of Old-Age Creationist & Historical Adam]
4. Fazale Rana & Hugh Ross, Who Was Adam? (NavPress 2005). [Scientific Aspects of Old-Age Creationist & Historical Adam]
B. Survey and critical response to latest scientific discussions
1. For a critical assessment of the claim that genetics and fossil evidence show human beings and apes share a common ancestry see, Casey Luskin, “Human Origins and the Fossil Record,” in Ann Gauger, Douglas Axe, & Casey Luskin, Science and Human Origins (Discovery Institute Press 2012).
2. For assessment and refutation of the claim that a mere human pair could not account for the present race see Ann Gauger, “The Science of Adam and Eve,” in Ann Gauger et.al, Science and Human Origins (Discovery Institute 2012). Also the article by Vern Poythress, “Adam versus Claims From Genetics,” in Westminster Theological Journal vol. 75 (2013).
C. Excellent monographs
1. Henri Blocher, Original Sin: Illuminating the Riddle (IVP 1997).
2. Alvin Plantinga, Where the Conflict Really Lies: Science, Religion, & Naturalism (OUP 2011).
3. Gerald Raum, Mapping the Origins Debate: Six Models of the Beginning of Everything (IVP 2012).
3. J.P. Versteeg, Adam in the New Testament: Mere Teaching Model or First Historical Man? 2nd ed., (Presb. & Reformed 2012).
These two articles are added to emphasize the need to be tentative when one makes judgments based on fragmentary and contestable evidence (re: excerpt from chapter 3 of the book by Science and Human Origin). However, this does not mean Christians may rely on the “God of the Gaps” approach when relating science and scripture. Christians need to go beyond merely finding faults with science or ‘guerrilla nitpicking’ and offer a constructive, coherent and comprehensive integration of science and faith. We should also appreciate the strength of the scientific enterprise found in its self-correcting procedures.
Additional note on science of genetics and human origins added on 9 July 2014
Supplementary Scientific Article 1:
On Human Origins, a Cautionary Tale with “Surprising” Biological Results
Ann Gauger July 1, 2014
Back in the late 1980s and early 1990s, DNA sequencing was sweeping the scientific scene with its power to answer a number of unsolved problems. Among the pioneers, in 1987 Cann et al. used mitochondrial DNA sequences to show that all women were the descendants of a single woman who lived some time around 200,000 years ago. (Similar work was done later for the Y chromosome.) Some subsequently used the idea to claim that this ancestor was Eve.
Francisco Ayala employed the same technique to challenge their analysis, and to demonstrate that we came from many more than two individuals. To do so, he chose to analyze a highly variable gene, HLA-DRB1, that is part of our immune system.
HLA-DRB1 is located in the human leukocyte antigen (HLA) complex. Most of the genes that encode the proteins involved in immune defense are located here. Some of these genes are highly variable in sequence, with hundreds of alleles each.
The variation is mostly limited to one small domain of each protein, called the peptide-binding site (PBS). Each PBS is where the rubber meets the road for recognizing and presenting foreign proteins to the immune system. Variation in the PBS increases the chance that at least some individuals in the population will survive a new parasite or disease; one of these proteins in the population may have a PBS with the right sequence to bind proteins from the attacker. The HLA gene can then direct the immune system to search and destroy anything carrying those foreign proteins. There is also evidence that having different copies of HLA antigens improves fertility.
Ayala sequenced the DNA encoding the PBS of HLA-DRB1 precisely because this gene has hundreds of variants in the population. He compared DNA from many Rhesus macaques, chimpanzees, and humans, and based on those sequences, he constructed a phylogenetic tree — a tree intended to show the evolutionary history of this gene.
His conclusion? To account for the current genetic diversity, there had to be at least 32 separate lineages of the gene at the time chimps and humans supposedly diverged from each other. And he explicitly argued that this ruled out Y-chromosome Adam and mitochondrial Eve.
But this wasn’t the end of the story. A few years later a group headed by Tomas Bergström challenged Ayala’s work, saying that he chose the wrong piece of DNA to study. The PBS sequence was inappropriate because it suffered from a high mutation rate and a high rate of gene conversion, both of which will cause an overestimation of the number of lineages for this gene.
Bergström’s group sequenced a neighboring region of the same gene that should not have these problems. They found that the estimated number of HLA-DRB1 lineages dropped from thirty-two to seven.
Now here’s where it gets interesting. The same group later re-sequenced a number of individual HLA-DRB1 genes, but this time they sequenced the whole gene, a monumental task given its size. Guess what they found? Only four lineages predate the supposed split of chimps and humans. A fifth arose about 5 million years ago.
Sequencing the whole gene gave them more complete data, and permitted a finer resolution of the sequence comparisons. It also revealed a number of very interesting things. The introns (the non-coding portions of the gene that get spliced out before it is turned into protein) showed that the four lineages appeared to have been separate for a long time, based on the differences between them. It also showed that there had been an explosion of genetic diversity about 500 to 350 thousand years ago. It was about that time we went from a few lineages of HLA-DRB1 to many, resulting in the incredible diversity we see today.
Let me restate this in case you have missed it. Four lineages of this gene appear to be ancient, because they are so different from one another (there are other possible explanations). But derived from each of those lineages are many, many alleles produced by some process that generates diversity fast. These newly appearing lineages tend to be more similar to one another, indicating that they are young. Surprisingly (there’s that word), their diversity appears to have arisen less than half a million years ago. This result has challenged the strongly held views of some immunologists, and is causing a re-evaluation of the field.
Here are a few take-home lessons:
1. Scientists would be wise not to make strong claims on incomplete data.
2. Science does tend to be self-correcting in the long run.
3. The diversity of the human HLA complex is not due to the ancient preservation of many lineages. Rather, most of the variation is recent.
4. From thirty-two to seven to four. That’s a remarkable journey, one that was entirely unexpected (there’s another of those words). Four alleles can be carried by just two individuals. [Emphasis added]
I leave you to draw your own conclusions. But don’t be hasty. There’s a whole genome yet to explore.
On Population Genetics Estimates
By Ann Gauger 03 August 2012
In his review of our book Science and Human Origins, Paul McBride wonders why I have not engaged the broader population genetics literature on human origins, but instead chose to focus on a single paper from 1995 by Francisco Ayala.
As I stated in the book, I chose that paper because in my opinion it presented the most difficult challenge to a very small bottleneck in our history as a species. If Ayala was right, and we shared thirty-two allelic lineages with chimps, then there was no way for a bottleneck as small as two individuals to have occurred. That kind of evidence, if substantiated, would have been conclusive. That’s why I found it so fascinating as I watched his analysis crumble in the light of later research.
I was very aware that others beside Ayala have investigated human origins, using other methods and data. I chose not to address those studies directly in the book because I wanted to focus on the intriguing problem of HLA-DRB1’s patchwork phylogenetic history. I did allude to them in discussing problems with retrospective analyses, however. The fact that I had not addressed those alternate estimates is one reason why I never claimed to have proved the existence of a two-person bottleneck, but rather questioned the rush to judgment against such a bottleneck on the part of others.
So now, let’s consider how much these other methods add to the discussion.
With the advent of modern sequencing capabilities, much more data on human variability is now available than Ayala had access to. The HapMap and the 1000 Genomes projects, in combination with new analytic techniques, have both been used to try to establish dates of divergence and sizes of ancient human populations. It is now common to use non-coding sequences scattered across our genome for this kind of analysis, in an attempt to “average out” unusual gene-specific behavior and effects due to selection.
For example, a study published in 2011 used multiple genome sequences sampled from different chromosomes to investigate different models of human origins. The authors estimated the ages of different autosomal chromosomes as compared to the X, Y, and mitochondrial age estimates, and then used those estimates to examine different models for human history using Bayesian analysis.
Figure 3, Blum and Jakobbson (2011) Deep Divergences of Human Gene Trees and Models of Human Origins. Mol Biol Evol 28:889-898.
Their conclusion was that we could have had a single out-of-Africa origin, provided that the effective population size at the time of our origin was about 14,000, with a range of 12,000 to 17,000, for that particular population model. Other models gave other estimates, as can be seen below.
Figure 4, Blum and Jakobbson (2011) Deep Divergences of Human Gene Trees and Models of Human Origins. Mol Biol Evol 28:889-898
Estimates in that paper for the time to our most recent common ancestor (MRCA) with chimps also varied considerably, depending on which chromosomes were studied, which models of migration were used, and how many bottlenecks were proposed. They estimated the time of divergence of true humans from the primate lineage to be some time in the last 380,000 to 2,400,000 years. That’s a very big range. I like this study, though, because they are explicit about the imprecision of their estimates, and the effects of different historical scenarios on results.
Published estimates for ancestral population sizes vary from 100,000 to 1,000. You can find some of them as references in the paper by Li and Durbin (2012) that McBride cited. Why such a large range of ancestral population sizes? First, the epoch chosen for study matters. The further back in time one goes, the more confounding factors can intervene. Population bottlenecks, changing selection, inbreeding, migratory behavior, strong selection for one gene accompanied by hitchhiking of neighboring genes—all these affect genome dynamics. Convergent evolution, parallel mutations, back-mutations, or gene conversion can obscure lineages and complicate tree-drawing. The method also matters. Linkage disequilibrium studies can’t go too far into the past because the recombination signal is either too small (too recent) or lost by repeated shuffling (too old), whereas allelic polymorphism studies, like Ayala’s, can go deep in evolutionary time.
But more worrying to me are the hidden assumptions in evolutionary models. Population genetics is a theory-laden subject, based entirely on neo-Darwinian assumptions. These assumptions, combined with over-simplifications required by current model building and/or mathematical analysis, can lead to erroneous claims about past genetic history.
Because of these difficulties, in my opinion it is an open question whether present genetic diversity provides sufficient information from which to draw conclusions about ancient populations. Determining events in deep human history may be beyond the reach of population genetics methods.
Supplementary Scientific Article 3: Genetic Data and Fossil Evidence Tell Differing Tales of Human Origins
New York Times 26 July 2012 by Nicholas Wade
Inquiries into human origins are on strong ground when genetic data and fossil evidence point in the same direction, but at present geneticists and paleoanthropologists have somewhat different stories to tell. All human fossil remains in Africa for the last 100,000 years, and probably the last 200,000 years, are of modern humans, providing no support for a coexistent archaic species. Another team of geneticists reported in 2010 the finding that Neanderthals had interbred 100,000 years ago with Europeans and Asians, but not Africans. This, too, conflicted with the fossil evidence in implying that modern humans left Africa 100,000 years ago, some 55,000 years before the earliest known fossil evidence of this exodus…
…These three claims of interbreeding have opened up a serious discordance between geneticists and paleoanthropologists. For digesting the geneticists’ claims, “sup with a long spoon,” advised Bernard Wood, a paleoanthropologist at George Washington University.
Richard Klein, a paleoanthropologist at Stanford University, said the new claim of archaic and modern human interbreeding “is a further example of the tendency for geneticists to ignore fossil and archaeological evidence, perhaps because they think it can always be molded to fit the genetics after the fact.”…
…Dr. Klein said the claims of interbreeding could be “a methodological artifact” in the statistical assumptions on which the geneticists’ calculations are based. The flaw may come to light when enough inconsistent claims are published. “Meanwhile, I think it’s important to regard such claims skeptically when they are so clearly at odds with the fossil and archaeological records,” he said.
Dr. Tishkoff said that she agreed on the need for caution in making statistical inferences, and that there are other events besides interbreeding, like a piece of DNA getting flipped around the wrong way, that can make a single DNA sequence look ancient. “But when you see it at a genomewide level, it’s harder to explain away,” she said.
Supplementary Scientific Article 4 on Fossils and Human Origins. Need for tentativeness and Cautionary Tales. Added 19 July 2014
Has Science Shown That We Evolved from Ape-like Creatures?
By: Casey Luskin (Center for Science & Culture)
Editor’s Note: This article appeared in a Supplemental Issue of Salvo Magazine on Science and Faith.
The meeting room was tense as Ronald Wetherington, a professor of anthropology at Southern Methodist University, took the podium. He was about to address the Texas State Board of Education before its vote in March 2009 over whether to inform students about scientific weaknesses in neo-Darwinian evolution.
And what Dr. Wetherington told the board is that there are no weaknesses. Human beings have “arguably the most complete sequence of fossil succession of any mammal in the world,” he said. “No gaps. No lack of transitional fossils. . . . So when people talk about the lack of transitional fossils or gaps in the fossil record, it absolutely is not true.” According to Wetherington, the field of human origins provides “a nice clean example of what Darwin thought was a gradualistic evolutionary change.”
It is not uncommon for evolutionary scientists like Wetherington (even those who teach at Christian universities) to be adamant about the evidence in favor of human evolution. Digging into the technical literature, however, we find a situation that’s starkly different from the one presented by Wetherington and many other evolutionary scientists who engage in public debates.
A closer look at the literature shows that hominin fossils generally fall into one of two categories—ape-like species or human-like species (of the genus Homo)—and that there is a large, unbridged gap between them. Despite the claims of many evolutionary paleoanthropologists, the fragmented hominin fossil record does not document the evolution of humans from ape-like precursors. In fact, scientists are quite sharply divided over who or what our human ancestors even were. Newly discovered fossils are often initially presented to the public with great enthusiasm and fanfare, but once cooler heads prevail, their status as human evolutionary ancestors is invariably called into question.
Early Human History
The details of the earliest stages of human origins are murky. They come from what UC–Berkeley paleoanthropologist Tim White once called “a black hole in the fossil record.”/1/ There are, to be sure, three main species that have emerged as contenders for the supposed common ancestor of humans and apes. But despite what is printed in the media, the extant fossils for all three species are fragmented and greatly disputed by experts.
When Orrorin tugensis was initially discovered in 2001, the New York Times ran a story titled “Fossils May Be Earliest Human Link.”/2/ The fossil itself—dubbed Millennium Man—was known only from “an assortment of bone fragments,”/3/ including pieces of the arm, thigh, and lower jaw, as well as some teeth. Debate over Orrorin has centered on whether it was an early hominin capable of walking upright, and on this point a 2007 commentary made a key admission: “All in all, there is currently precious little evidence bearing on how Orrorin moved.”/4/
When Sahelanthropus tchadensis was first discovered in 2002, the popular science journal New Scientist claimed that “the new species is close to the common ancestor of humans and chimpanzees.”/5/ But since that fossil was known only from a skull and some jaw fragments, experts naturally disagreed. For example, Brigitte Senut, a leading researcher at the Natural History Museum in Paris, said, “I tend towards thinking this is the skull of a female gorilla.”/6/ Three paleoanthropologists subsequently concluded in an article in Nature that “Sahelanthropus was an ape.”/7/
The most recent hyped-up hominin fossil find was Ardipithicus ramidus, dubbed “Ardi” by its promoters in the media. The Discovery Channel ran the headline “‘Ardi,’ Oldest Human Ancestor, Unveiled” and quoted Tim White as stating that Ardi was “as close as we have ever come to finding the last common ancestor of chimpanzees and humans.”/8/ Doubts arose, however, after news reports acknowledged that “some portions of Ardi’s skeleton were found crushed nearly to smithereens and needed extensive digital reconstruction,” and that its pelvis initially “looked like an Irish stew.”/9/ Later, technical papers in both Science and Nature disavowed claims that Ardi was a human ancestor./10/ According to Time magazine, one of the authors of those papers, Esteban Sarmiento, “regards the hype around Ardi to have been overblown.”/11/
Australopithecines Are Like Apes
While early hominin fossils are controversial, due to their fragmented condition, there is one major group—the australopithecines—that is widely promoted as directly ancestral to humans. The primary claim is that australopithecines had the head of a chimpanzee but a body that allowed it to walk upright, like humans.
Despite the prevalence of that standard view, authorities have found that the fingers, arms, chest, hand bones, striding gait, shoulders, abdomen, inner-ear canals, developmental patterns, toes, and teeth of australopithecines point away from their being human ancestors and/or suggest that they didn’t have human-like bipedal locomotion./12/ For example, an article in Nature observed that the most complete australopithecine specimen—the famous fossil Lucy—was “quite ape-like,” especially with respect to her “relatively long and curved fingers, relatively long arms, and funnel-shaped chest.”/13/ The article reported that Lucy’s hand bones suggest that she “‘knuckle-walked’, as chimps and gorillas do today.”/14/
Paleoanthropologist Leslie Aiello, who served as head of the anthropology department at University College London, stated that when it comes to locomotion, “Australopithecines are like apes, and the Homo group are like humans. Something major occurred when Homo evolved, and it wasn’t just in the brain.”/15/
A Big Bang Origin of Homo
When the human-like members of our genus Homo appear, they do so abruptly. A paper in the Journal of Molecular Biology and Evolution called the appearance of Homo sapiens “a genetic revolution” in which “no australopithecine species is obviously transitional.”/16/ In a 2004 book, the famed evolutionary biologist Ernst Mayr explained that “the earliest fossils of Homo, Homo rudolfensis and Homo erectus are separated from Australopithecus by a large, unbridged gap” without “any fossils that can serve as missing links.”/17/
The lack of fossil evidence for this hypothesized evolutionary transition was confirmed by three Harvard paleoanthropologists, who wrote:
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./18/
And the good news? “Although we lack many details about exactly how, when, and where the transition occurred from Australopithecus to Homo,” the three went on, “we have sufficient data from before and after the transition to make some inferences about the overall nature of key changes that did occur.”/19/
In other words, the fossil record provides us with ape-like australopithecines (“before”) and human-like Homo (“after”), but not with fossils documenting a transition between them. In the absence of intermediaries, we’re left with “inferences” of a transition based strictly upon the assumption of Darwinian evolution. No wonder one commentator argued that if we take the fossil evidence at face value, it implies a “big bang theory” of the appearance of our genus Homo./20/
Resistance Isn’t Futile
Despite the constant drumbeat of media stories announcing the discovery of the latest “missing link,” the evidence shows that human-like forms appear abruptly in the fossil record, without any fossils connecting us to our alleged ape-like evolutionary ancestors. This contradicts the expectations of neo-Darwinian evolution and suggests that unguided evolutionary mechanisms do not account for the origin of our species. •
Casey Luskin, a senior editor of Salvo, is co-founder of the Intelligent Design & Evolution Awareness (IDEA) Center and Program Officer in Public Policy and Legal Affairs at the Discovery Institute.
1. Tim White, quoted in Ann Gibbons, “In Search of the First Hominids,” Science (Feb. 15, 2002), 295:1214–1219.
2. John Noble Wilford, “Fossils May Be Earliest Human Link,” New York Times (July 12, 2001).
3. Rick Potts and Chris Sloan, What Does It Mean to Be Human? (National Geographic, 2010), p. 38.
4. Esteban E. Sarmiento, Gary J. Sawyer, and Richard Milner, The Last Human: A Guide to Twenty-Two Species of Extinct Humans (Yale Univ. Press, 2007), p. 35.
5. Jeff Hecht, “Oldest hominid skull shakes human family tree,” New Scientist (July 10, 2002).
6. “Skull find sparks controversy,” BBC News (July 12, 2002).
7. Milford H. Wolpoff et al., “Sahelanthropus or ‘Sahelpithecus’?” Nature (Oct. 10, 2002), 419:581–582.
8. Jennifer Viegas, “‘Ardi,’ Oldest Human Ancestor, Unveiled,” Discovery News (Oct. 1, 2009).
9. Michael D. Lemonick and Andrea Dorfman, “Ardi Is a New Piece for the Evolution Puzzle,” Time (Oct. 1, 2009).
10. Esteban E. Sarmiento, “Comment on the Paleobiology and Classification of Ardipithecus ramidus,” Science (May 28, 2010), 328:1105b; Bernard Wood and Terry Harrison, “The evolutionary context of the first hominins,” Nature (Feb. 17, 2011), 470:347–352.
11. Eben Harrell, “Ardi: The Human Ancestor Who Wasn’t?” Time (May 27, 2010).
12. For a more detailed discussion of the fossil evidence and human origins, see Casey Luskin, “Human Origins and the Fossil Record” in Science and Human Origins (Discovery Institute Press, 2012), pp. 45–83.
13. Mark Collard and Leslie C. Aiello, “From forelimbs to two legs,” Nature (March 23, 2000), 404:339–340.
15. Leslie Aiello, quoted in Richard Leakey and Roger Lewin, Origins Reconsidered: In Search of What Makes Us Human (Anchor Books, 1993), p. 196.
16. John Hawks et al., “Population Bottlenecks and Pleistocene Human Evolution,” Journal of Molecular Biology and Evolution (2000), 17(1):2–22.
17. Ernst Mayr, What Makes Biology Unique? (Cambridge Univ. Press, 2004), p. 198.
18. Daniel Lieberman, David Pilbeam, and Richard Wrangham, “The Transition from Australopithecus to Homo,” in Transitions in Prehistory: Essays in Honor of Ofer Bar-Yosef (Oxbow Books, 2009), p. 1 (internal citations removed).
20. “New study suggests big bang theory of human evolution,” (Jan. 10, 2000) at http://www.umich.edu/~newsinfo/Releases/2000/Jan00/r011000b.html.