Until the advent of Darwinian evolution, most Christians believed that the entire human race actually descended from our literally-real first parents, Adam and Eve. Many still do. In 1950, Pope Pius XII issued an encyclical, Humani Generis, in which he wrote that “revealed truth and … the magisterium of the Church teach” that Original Sin is “a sin truly committed by one Adam [ab uno Adamo], and which is transmitted to all by generation, and exists in each one as his own” (no. 37). The current Catechism of the Catholic Church: Second Edition tells us that “Adam and Eve committed a personal sin… which will be transmitted by propagation to all mankind” (CCC, 404).
Still, this account of our literal first parents and Original Sin, which is the essential rationale for the need of Christ as a Redeemer, has been challenged by modern scientific claims on two fronts: (1) the Christian belief that true man suddenly appeared in the form of Adam has been replaced with the standard theory of human evolution in which progressive changes in early primates evolved the consciousness and intelligence of modern man, with no clear line of demarcation marking his initial appearance, and (2) the claim that our human species arose from a single pair of first parents has been replaced with evolution taking place in large populations whose number never saw a bottleneck (reduced population) of just two individuals.
The former claim arises largely from the evidence of paleoanthropology, revealed in the gradual, progressive development of tools over time, and the latter arose particularly from the work of geneticist Francisco Ayala, whose often-cited mid-1990s studies maintained that the human population never was fewer than several thousand individuals.
Instant Appearance of the First True Human Beings
Paleontology discovers progressive improvement in tools made by evolving primates, which seems to correlate with development of hominin brains and anatomy. (Hominin is a term that includes recent humans together with extinct ancestral and related forms.) This sequence finally blends into the sophisticated tool-making and other abilities of modern man. Yet, there appear to be no sudden signs of a “spiritual-souled” Adam. Neo-Darwinists infer that all this improvement can be explained in naturalistic terms. Yet, what these facile materialist scenarios overlook is the fact that the rational case for man’s essential superiority over brute animals remains robust. Christian philosophy argues that true man is marked by intellectual activities of understanding, judging, reasoning and free will that manifest the spiritual soul’s presence ((Bonnette, Origin, pp. 69-71; 103-110)
Complex sentient behaviors of irrational animals enabled early primates to produce primitive stone tools, even including early Acheulean stone hand-axes exhibiting some symmetry—wrought by Homo erectus hominins dating back 1.4 million years. Still, it wasn’t until the early Middle Pleistocene period, some three-quarters of a million years ago, that later hand-axes appeared having a congruent, three-dimensionally symmetrical shape that apodictically demonstrates true human intellection (Bonnette, Origin, p. vix). This, as well as evidence of early controlled use of fire, appears about that time— evincing the first unequivocal presence of the human spiritual soul. These sophisticated artifacts may be viewed as scientific evidence, which also has an important philosophical implication, namely, that such artifacts necessarily imply the activity of an intellectual agent – a qualitatively superior, true human being with a spiritual soul (Bonnette, Origin, pp. 163-164). True man may have been present earlier, but remains thus far undetected.
Since mere matter can never evolve into spirit, true man must have appeared instantly at some point —regardless of the misreading of fossil tool evidence by Neo-Darwinians. Scientific failure to detect that fact and that moment in no way undermines the philosophical necessity of its reality. The scientific possibility of a literal Adam and Eve remains intact despite the gradual improvement of toolmaking. Moreover, the philosophical proof that there must be a first true human being lends support to the credibility of Adam and Eve, since having a spiritual-souled first true man is part of that biblical account.
The Challenge Posed by Modern Genetics
Until very recently, it has been accepted scientific dogma that human beings could not have arisen from a single mating pair of first true humans. This claim has been based on the distribution of single nucleotide polymorphisms in the human population, and coalescence and lineage disequilibrium studies. Researchers have estimated the hominin population at the time of our origin had to be in the thousands. Indeed, some researchers claim that there has never been a hominin population smaller than one thousand in the last two million years (Hawks, et al.).
Yet these estimates are subject to confounding error because of the assumptions involved, for example, “…a constant background mutation rate over time, lack of selection for genetic change on the DNA sequences being studied, random breeding among individuals, no migrations in or out of the breeding population, and the assumption of a constant population size”(Gauger)—such that DNA sequence differences (polymorphisms) alone are insufficient to determine effective population size (Sjödin et al.; Hawks; see also McKnight, et al.).
Perhaps the best example of such a failure is the study by geneticist Francisco Ayala published in Science (1995), in which he claimed that a mating pair of just two first true humans was scientifically impossible. Ayala based his claim on the large number of versions (alleles) of the gene HLA-DRB1 that are found in the present human population. Ayala claimed that there were thirty-two ancient lineages of HLA-DRB1 prior to the Homo (human)/Pan (chimpanzee) split, which he said occurred six million years ago. The problem is that each individual carries only two versions of a gene – so that there would be no way that just two individuals could have possibly passed on all those alleles at any time since the lineages split. A bottleneck (reduced population) of just two true human beings, Adam and Eve, appeared to be scientifically impossible.
But it turned out that Ayala’s claim of thirty-two ancient HLA-DRB1 lineages contained methodological errors. The DNA he chose was subject to strong selection, hypermutation, and gene conversion, which skewed his results. Recognizing the problem, Tomas Bergström et al. published a study (1998) showing just seven such alleles at the time of the Homo/Pan split, with most of the present genetic diversity appearing in the last quarter million years. Still later, another study (2007) by von Salomé et al., inferred that only four such lineages existed more than five million years ago, with a few more appearing shortly thereafter.
While this article is too short to analyze all the genetics pertinent to these studies, often overlooked is the inherent epistemic weakness of these retrospective calculations. It is all too easy to make false assumptions that invalidate results. The assumptions of random breeding among individuals, constant mutation rates, or constant population size may be incorrect. Even the methods used for analysis can make a difference. One need merely think of the errors already noted in present day computer models about trends of climate change.
Indeed, claims that “Adam and Eve are scientifically impossible,” are not scientific, as science is always subject to revision, as we shall see.
The Proposed “Interbreeding Solution”
Given the seemingly problematic genetics of a literal Adam and Eve, philosopher Kenneth W. Kemp, writing in the American Catholic Philosophical Quarterly (2011), proposed an alternative solution in the form of the interbreeding hypothesis, that is, that present genetic diversity in genes, such as HLA-DRB1, might be explained through interbreeding between Adam and Eve’s true human descendants and their subhuman “relatives” in the same biological population.
Kemp’s hypothesis meets the theological requirements that Adam and Eve must be the first true human beings and that all true humans today must be their biological descendants. In any such scenario, the possession of intellect by true men would enable them to outcompete their subhuman “cousins,” thus explaining why such nearly identical subhumans are no longer extant.
Given that studies by Bergström et al. and von Salomé et al. showed that many fewer excess alleles need to be explained than Ayala initially claimed—but that the estimate hovers on the border of what can pass through just two ancestors, it is possible that such an interbreeding solution might still be needed in order to explain present genetic diversity.
But, the question remains as to whether such a potentially ethically-problematic solution, entailing sexual intercourse between true men and subhuman animals, is really necessary.
More Recent Genetic Studies
In 2017, a series of unexpected events occurred that amply illustrate the need for caution in making claims about human beings’ origin. Biologist Dennis Venema published the claim that it was as certain as that the earth revolves around the sun that we came from a population of thousands. This precipitated a prolonged discussion by scientists on the website, Biologos, which revealed that, despite all the claims, no one had directly tested whether or not we could have come from a first human pair. Recounting the story at Evolution News, molecular biologist Ann Gauger described how two scientists decided to finally directly test the possibility. They ran different computer models and, amazingly, they found that:
A bottleneck of two that is older than 500,000 years ago cannot be ruled out. That does not mean such a bottleneck ever existed, but rather that the possibility cannot be excluded. Future models may change that number of 500,000 years, up or down…
This is based on an analysis of the genetic data run by Drs. Schaffner and Swamidass, themselves evolutionary biologists and not ID supporters.
In the context of a lengthy and highly technical analysis on his blog, Dr. S. Joshua Swamidass, summarized the results as follows:
Swamidass realized that there was yet another way to disprove a first pair. If it could be shown that human beings share too many alleles (more than four) of any gene with chimps or gorillas, that would argue for our common descent from a population of more than two. (Adam and Eve could pass along only four.) This passing along of alleles between species by common descent is known as trans-species polymorphism (TSP). The gene family most likely to demonstrate TSP is the HLA family, including HLA-DRB1, the gene Francisco Ayala studied in 1995 in an attempt to demonstrate Adam and Eve were not possible.
In light of the model results described above, Dr. Swamidass re-examined Ayala’s work. Swamidass found a paper, published in BMC Evolutionary Biology (2016), that analyzed the genetic networks of HLA genes, along with about 12,000 other genes. This study found that the apparent TSP of HLA-DRB1, along with other HLA genes (HLA-DPB1, HLA-C, HLA-A, and HLA-B), is probably due to convergent evolution. Human alleles are mutating over time toward the same sequence, likely due to selection that favors that sequence.
Referring to the results of that paper, Swamidass notes, “… HLA-DRB1 is the most variable HLA gene. It is notable for having over 500 squares in the DNA of about merely 1,000 individuals, compared with an expected number of less than 10. That means if we had tried to put the DNA into a tree, we would see at least 500 mutations discordant with a phylogenetic tree. This is just a stunning result, because it means that HLA-DRB1 alleles are just not well described as a tree.”
What Swamidass means is that HLA-DRB1 shows signs of convergent evolution. The 500 squares he refers to are places where the HLA-DRB1 DNA sequence is more similar than it should be, showing signs of converging on a particular sequence. Thus any similarity between chimpanzee and human HLA-DRB1 sequences is probably due to convergent evolution also, not TSP. This considerably weakens TSP as a challenge to a first pair.
Any conclusions based on the assumption of TSP are called into question. At this point, it seems even TSP cannot be used to rule out a first hominin mating pair.
This is on-going, exciting research, not yet published in a peer reviewed journal. It shows that the claim that we had to come from a population of thousands was based on presumption and not proof. The claim that a first pair is impossible, when tested directly, was wrong. Finally, a first human mating pair is possible, but not proven.
I am indebted to Dr. Ann Gauger, who pointed out all this recent research and its implications to me, and who has assisted me in my preparation of the scientific sections.
Conclusion
It was never the intent of this paper to offer scientific proof of Adam and Eve’s literal reality. The sole purpose has been to show that they are not scientifically impossible.
Based on the best available evidence and analysis, this goal has been achieved.
The most recent research indicates that the best likelihood for there being two first parents for the human race is prior to half a million years ago. This finding comports significantly with my own speculation stated at the beginning of this article, namely, that, based on intellect-evincing artifacts, the probable time for the first true human beings—Adam and Eve—would be some three-quarters of a million years ago.
This philosophical inference that the makers of such artifacts must be true human beings means that they would be proper candidates for being identical with the possible “first hominin mating pair” discussed in the previous section.
And yes, as Swamidass points out, given their ancient time frame, this would make them “the common ancestor of Homo sapiens, Denisovans, and Neanderthals.”
Few understand that adequate speculative treatment of a literal Adam and Eve requires proper correlation of three disciplinary perspectives: theological, philosophical, and natural scientific. Theologically, Adam and Eve must be the first true human beings and all true men must be their descendants. Philosophically, the first true man must be the first hominin possessing intellect and a spiritual soul – as evinced by artifacts, such as those artistic stone hand axes of three-quarters of a million years ago. This is the reason why “candidates” proposed more recently in time cannot possibly be the true first parents, since there is evidence that true humans would chronologically precede them. Finally, in terms of natural science, it must be shown that – unless there is need for recourse to the interbreeding hypothesis – a bottleneck of just two true first human beings is possible. A credible case for that very possibility in the speculative time frame that I propose has just been offered, as shown above.
Therefore, a literal Adam and Eve is scientifically possible.
Of course, the positive evidence for the actual existence of a literal Adam and Eve lies, not in natural science or philosophy, but in the two thousand years of Christian miracles, singularly embodied in the death and resurrection of Jesus Christ, the Redeemer promised by God to our first parents, Adam and Eve, after they had personally committed Original Sin. To Christians, these miracles, especially when combined with the newfound evidence for the scientific possibility of a literal Adam and Eve, will serve to demonstrate the rational credibility of this foundational doctrine of the Faith.
Post Script
Peer-Reviewed Success!
While the earlier cited comments by Dr. Joshua Swamidass about the first true human beings being possible 500,000 years ago were taken from his online blog, none of this was found in peer-reviewed journals. Subsequent to publication of the analysis that I present above, a peer-reviewed article on this same topic was, indeed, published by researchers O. Hossjer and Ann Gauger.
These scientific researchers made a break-through achievement by succeeding in modeling “the demographic ancestry of humanity using the simplest of assumptions, with a homogeneous population whose size can vary over time.” In so doing, Drs. Hossjer and Gauger demonstrated “that a single-couple origin of humanity as recent as 500kya is consistent with data.” In a word, these scientists proved that the hypothesis presented in my earlier analysis could be verified in a realistic model.
This peer-reviewed scientific article demonstrated that a single mating couple, the biblical Adam and Eve, were scientifically possible and could be demonstrated as such according to a realistic genetic model – as long as they are dated at least five hundred thousand years ago. This finding, as shown earlier in this paper, comports perfectly with the philosophical and theological requirements that the first true human beings, Adam and Eve, actually existed and that all true human beings on planet Earth are descended from this single pair of first parents.
Given the number of those who, since Francisco Ayala’s faulty 1995 genetic study, have confidently insisted on the “scientific impossibility” of a literal Adam and Eve, one can scarcely overstate the importance of this peer-reviewed study by Drs. Hossjer and Gauger. These researchers have finally shown that an entirely realistic genetic model for a literal Adam and Eve now exists, provided we date our first parents far enough back in time.
Critical Philosophical Point
A critical philosophical point must also be made. One cannot overstate the importance of establishing the correct date of true human beings first appearance. Philosopher of religion, William Lane Craig, points out that the first true humans must date back to prior to 500,000 years ago, based on evidence of higher levels of cognitive sophistication.
What needs to be pointed out, though, is that these higher levels of “cognitive sophistication” are not mere gradual developments of sentient abilities. Rather, they represent a leap to a qualitatively superior kind of operation and to a spiritual mode of existence.
That is why I noted earlier the critical importance of dating the discovery of Acheulean symmetrical stone hand axes and the controlled use of fire to about three-quarters of a million years ago. This is well before the half million years ago needed for the scientific possibility of a single mating pair of first true humans. Any clear evidence of true human beings at that early a date forces the time for Adam and Eve’s appearance at least that far back in time.
Unfortunately, many commentators do not seem to be aware that these signs of higher levels of “cognitive sophistication” are not merely more complex forms of sentient behavior. Rather, they represent the qualitatively superior genuinely spiritual operations of a spiritual, intellectual human soul.
Without venturing into the Aristotelian science of philosophical psychology in depth, some indication of the reality of these new spiritual abilities in true human beings can be grasped by considering the difference between the sense image and intellectual concept. For example, one can imagine a triangle. (Most people immediately imagine an equilateral one!) But then, try to imagine the concept of “triangularity.” This simply cannot be done, since there are an infinite number of possible variant shapes, sizes, and physical instances of triangles. Yet, we clearly understand the meaning of “triangularity” as a geometrical concept defining any and all three-sided plane figures.
Again, it is easy to imagine a single human being or even many thousands of them standing in an open plaza – although the latter is actually reduced to a sea of heads! But one simply cannot imagine the universal concept of “humanity,” since its meaning in terms of the essence “rational animals” must apply to every conceivable human being that has ever lived or could even possibly exist at some future time. That is simply because we do not imagine a concept. We understand a concept’s meaning – a meaning that is not tied to any particular material instance of its application.
Even more evident is the spiritual nature of such a concept as justice. The image associated with the term, “justice,” may be that of a blind lady holding scales or of a court building or even the written word, “justice.” But everyone knows that such images are not the real meaning of justice in itself – a term whose meaning must apply to every possible just act.
Human language is filled with thousands of words that have universal applications of the meanings they represent. This is what gave rise in the last century to great interest in ape-language studies – a fascinating speculation that our fellow non-human primates might be able to be taught human language using American Sign Language or computer key boards. This hypothesis, in fact, gave rise to the famous “Planet of the Apes” movies that were spawned in that era and which continue even to the present day.
Unfortunately, careful scientific and philosophical analysis showed that our non-human primate brethren simply lack any true understanding of language structure or of the universal meanings of words. Like other animals, these non-human primates were adept at associating images with images and images with objects, but they possessed no actual understanding of the universal concepts for which these images were merely concrete, particular sense representations. Such critiques took their toll and eventually ape-language studies largely lost serious interest and funding.
Sense images are always under material conditions of space, shape, color, and so forth, while intellectual concepts – being universal in nature — are entirely free of such particular physical properties. Since physical matter is always under such material conditions, human language and intellectual abilities must operate independently of matter.
From this, it follows that the human life principle or soul not only operates free of such material conditions, but rather, is in fact free from any dependence on such physical entities for its very existence – since what acts independently of matter must exist independently of matter. In a word, the radical distinction between sense images and intellectual concepts shows that true human beings possess an intellectual, spiritual soul. This line of argument is more fully developed elsewhere.
This philosophically critical step — showing that true human beings have a qualitatively superior intellectual life and spiritual souls — is what must be added to any analysis of the first appearance of true human beings on Earth. Adam and Eve must have been these first true human beings.
Therefore, correct dating of the first unequivocal signs of genuine intellectual activity also shows that Adam and Eve must date at least that far back in time.
For example, those three-quarter million year old Acheulean hand axes mentioned earlier were congruently symmetrical. That meant that in order to carve the shape of the side facing the maker, one had to imagine and understand the congruent geometry of the unseen opposite side – clearly an intellectual act. In fact, Acheulean stone hand axes have been properly described as being genuinely artistic in nature. This dates intellectual activity – and thereby, Adam and Eve – to this very ancient time period, possibly even earlier.
This is not merely a paleoanthropological fact. Rather, it is a conclusion forced by philosophical necessity – proving the very ancient appearance of our first parents. Still, so great a time span back to Adam is no more problematic for an individual person living in its midst than it would have been for someone living half way between the time of Adam and Abraham, using the two thousand year span often calculated by biblical fundamentalists. Adam would still be a thousand years in the distant past with Abraham yet to be awaited for, patiently, a thousand more years in the distant future.
Any genuinely complete explanation of why a literal Adam and Eve are scientifically possible must include the foregoing philosophical observations. This radical step from mere sense powers to the qualitatively superior abilities of a spiritual-souled human being is precisely that which absolutely required God’s decisive intervention at some point in time to create the first true human beings – primates with genuine intellectual powers and spiritual souls. Thus did appear, at least three-quarters of a million years ago, the single mating pair, Adam and Eve – the first parents of all true human beings, who subsequently have lived on planet Earth.
An earlier version of this article appeared in Strange Notions.
Featured: God presents Eve to Adam, mosaic, Monreale Cathedral, Sicily (12th century).
