Pure myth! That is today’s typical view of a literal Adam and Eve. Yet, contrary to current skepticism, a real Adam and Eve remain credible—both in terms of Catholic doctrine and sound natural science.

By calling the Genesis story a “myth,” people avoid saying it is mere “fantasy,” that is, with no foundation in reality at all. While rejecting a literal first pair of human parents for all mankind, they hope to retain some “deeper” truth about an original “sinful human condition,” a “mythic” meaning. They think that the latest findings in paleoanthropology and genetics render a literal pair of first true human parents to be “scientifically impossible.”

The prevailing assumption underlying media reports about human origins is that humanity evolved very gradually over vast periods of time as a population (a collection of interbreeding organisms), which itself originally evolved from a Homo/Pan (human/chimpanzee) common ancestor millions of years ago. Therefore, we are not seen as descendants of the biblical Adam and Eve.

This universal evolutionary perspective leads many Catholics and others to conclude that a literal Adam and Eve is “scientifically impossible” for two reasons: First, paleoanthropologists deny the sudden appearance of intelligent, self-reflective, fully-human primates, but rather view the emergence of consciousness and intelligence as taking place slowly and incrementally over long periods of time. Second, in light of recent findings in molecular biology, especially from studies based on genetic data gleaned from the Human Genome Project, it is claimed that the hominin population (the primate group from which modern man is said to have arisen) has never had a bottleneck (reduced population) of a single mating pair in the last seven or more million years: no literal Adam and Eve. Many succumb to the modernist tendency to “adjust” Church teaching to fit the latest scientific claims—thus intimidating Catholics into thinking that divinely revealed truths can be abandoned—“if need be.”

This skepticism of a literal Adam and Eve begs for four much needed corrections.

First, Church teaching about Adam and Eve has not, and cannot, change. The fact remains that a literal Adam and Eve are unchanging Catholic doctrine. Central to St. Paul’s teaching is the fact that one man, Adam, committed original sin and that through the God-man, Jesus Christ, redemption was accomplished (Romans 5:12-21; 1 Cor. 15: 21-22). In paragraphs 396-406, the Catechism of the Catholic Church, speaks of Adam and Eve as a single mating pair who “committed a personal sin, but this sin affected the human nature that they would then transmit in a fallen state” (CCC, 404). “Baptism, by imparting the life of Christ’s grace, erases original sin and turns a man back toward God, but the consequences for nature, weakened and inclined to evil, persist in man and summon him to spiritual battle” (CCC, 405). The doctrines surrounding original sin cannot be altered “without undermining the mystery of Christ” (CCC, 389).

Today, many think that Pope Pius XII’s encyclical Humani generis did not definitively exclude theological polygenism. What they fail to notice, though, is that the Holy Father clearly insists that Scripture and the Magisterium affirm that original sin “proceeds from a sin truly committed by one Adam [ab uno Adamo]” and that this sin is transmitted to all true human beings through generation (para. 37). This proves that denial of a literal Adam (and his spouse, Eve) as the sole first genuinely human parents of all true human beings is not theologically tenable.

Second, rational human nature itself requires that mankind made an instant appearance on planet Earth. Paleoanthropological claims of gradual appearance of specifically human traits fail to comport with a true philosophy of human nature. Reflecting classical Christian thought, St. Thomas Aquinas demonstrates that true man is distinguished essentially from lower animals by possession of an intellectual and immortal soul, which possesses spiritual powers of understanding, judgment, and reasoning (Summa theologiae I, 75). While these qualitatively superior abilities are manifested through special forms of tool making or culture or art, they need not always be evident in the paleontological record. Sometimes true men share mere animal survival behavior and sometimes truly human behavior is lost to modern sight due to the ravages of time. What matters is that genuinely spiritual powers are either present or not, and that these alone bespeak the presence of true man. Irrational animals, including subhuman primates, are capable of complex sentient behaviors often approaching or imitating the rational activities of true man. But an animal either possesses a spiritual, intellectual soul or not. Thus at some point in time, true man suddenly appears—whether visible to modern science or not. Before that time, all subhuman behavior manifests merely material sensory abilities. The fact that positivistic scientists cannot discern the first presence of true man is hardly remarkable.

Third, a correct understanding of the scientific (inductive) method reveals that it cannot ever logically exclude the possibility of two sole founders of humanity. Natural scientific studies employ the inductive method of reasoning. Empirically observed data is employed to form testable hypotheses. Molecular biologists use computer models in an attempt to validate such hypotheses and reach conclusions about genetic conditions in early primate populations. In this process, some researchers have committed the logically invalid move of inferring from particular data to the universally negative claim that a literal Adam and Eve is impossible. Such methodology produces, at best, solely probable conclusions, based on available evidence and the assumptions used to evaluate the data. There is the inherent possibility that an unknown factor will alter the conclusion, similarly as was the unexpected discovery of black swans in Australia, when the whole world “knew” all swans were white.

Fourth, specific scientific arguments against Adam and Eve have proven not as forceful as many presently believe (Gauger 2012). For example, some have claimed that effective population size estimates for the last several million years would not permit just two true humans to have lived during that time. Still, the technical concept of average effective population size estimates should not be confused with an actual “bottleneck” (a temporarily reduced population) which may be much smaller. Effective population size estimates can vary from as high as 14,000 (Blum 2011) to as low as 2,000 (Tenesa 2007), depending on the methods used.

Such calculations rely upon many assumptions about mutation rate, recombination rate, and other factors, that are known to vary widely. All of this entails retrospective calculations about events in the far distant past, for which we have no directly verifiable data. For such reasons, some experts have concluded that effective population size cannot be determined using DNA sequence differences alone (Sjödin 2005; Hawks 2008).

Indeed, the most famous genetic study proclaimed as a “scientific objection” to Adam and Eve turned out to be based on methodological errors. An article by geneticist Francisco J. Ayala appearing in the journal, Science (1995), led many to believe that a founding population of only two individuals was impossible. Ayala based his challenge to monogenism (two sole founders of humanity) on the large number of versions (alleles) of the particular gene HLA-DRB1, which are present in the current population. Accepting the common ancestor theory, he claimed that there were thirty-two ancient lineages of the HLA-DRB1 gene prior to the Homo/Pan split (approximately seven million years ago). Over time, these “pre-split” lineages, themselves, evolved into the new additional versions present today. Because each individual carries only two versions of a gene, a single founding pair could not have passed on the thirty-two versions that Ayala claimed existed some seven million years ago—either at that time or at any time since. A bottleneck of just two true humans, Adam and Eve, was “scientifically impossible.”

However, Ayala’s claim of thirty-two ancient HLA-DRB1 lineages (prior to the Homo/Pan split) was wrong because of methodological errors. The number of lineages was subsequently adjusted by Bergström (1998) to just seven at the time of the split, with most of the genetic diversity appearing in the last 250,000 years. A still later study coming out of Bergström’s group inferred that just four such lineages existed more than five million years ago, but that a few more appeared soon thereafter (von Salomé 2007). While two mating hominins can transmit four lineages, the few additional later ones still require explanation.

These genetic studies, based on many assumptions and use of computer models, do not tell us how the origin of the human race actually took place. But, they do show (1) that methodological limitations and radical contingency are inherent in such studies, which are employed to make retroactive judgments about deeply ancient populations that can never be subject to direct observation, and (2) that present scientific claims against the possibility of a literal Adam and Eve are not definitive (Gauger 2012, 105-122).

Philosopher Kenneth W. Kemp and others have suggested that interbreeding between true humans and subhuman primates in the same biological population might account for presently observed genetic diversity (Kemp 2011). Such interbreeding is not to be confused with the marriages between true human siblings and cousins which would have occurred in the first generations following Adam and Eve, which unions were a necessary part of God’s plan for the initial propagation of mankind (Gen. 1:28).

The difficulty with any interbreeding solution (save, perhaps, in rare instances) is that it would place at the human race’s very beginning a severe impediment to its healthy growth and development. Natural law requires that marriage and procreation take place solely between a man and a woman, so that children are given proper role models for adult life. So too, even if the union between a true human and a subhuman primate were not merely transitory, but lasting, the defective parenting and role model of a parent who is not a true human being would introduce serious disorder in the proper functioning of the family and education of children. Hence, widespread interbreeding is not an acceptable solution to the problem of genetic diversity.

Moreover, given the marked reduction in the number of ancient HLA-DRB1 alleles found by the later genetic studies of Bergström and von Salomé, it may turn out that no interbreeding is needed at all, or at most, that very rare instances of it may have occurred. Such rare events might not even entail the consent of true human beings, since they could result from an attack by a subhuman male upon a non-consenting human female.

A literal Adam and Eve remains rationally, scientifically credible.

Since the same God is author both of human reason and of authentic revelation, legitimate natural science, properly conducted, will never contradict Catholic doctrine, properly understood. Catholic doctrine still maintains that a literal Adam and Eve must have existed, a primal couple who committed that personal original sin, which occasioned the need for, and the divine promise of, the coming of the Redeemer, Jesus Christ.

Editor’s note: The image above is a detail from “The Fall of Man” painted by Hendrik Goltzius in 1616.