The Genealogical Adam and Eve

by S. Joshua Swamidass

  Now, our hypothesis is specified enough to objectively evaluate with evidence. As stated here, we will find there is no evidence for or against this hypothesis. As surprising as this may sound, this hypothesis is outside the view of science. The only way evolution presses on the Genesis story of Adam and Eve is by telling us the story of other people outside the Garden.

  THEOLOGICALLY MOTIVATED QUESTIONS

  A possible objection arises from a commitment to keep science secular, free from religious agendas. In science, we do not take religious claims as unquestioned facts. Still, the spirit of science is curiosity. We take questions seriously. We study them rigorously and answer them honestly. Theological concerns should never dictate scientific conclusions. At the same time, there is no good reason to ignore questions from theology.

  Alongside Adam and Eve, two more examples of theologically motivated questions in the scientific literature are the dating of the Dead Sea Scrolls and a medical analysis of Jesus’ crucifixion.

  The book of Isaiah, Christians argue, contains a prophecy that the Messiah would “take away the sins of many,” then be “cut off from the land of the living,” and then “see the light of life” (Heb 9:28; Is 53:8, 11). This text appears to be a prediction about the Resurrection of Jesus. Was this text added before or after Jesus walked the earth? In 1947, a cache of ancient scrolls was discovered by a Bedouin shepherd in a cave near Qumran, near the Dead Sea. This cache included very early manuscripts of different parts of the Bible, including a complete scroll of Isaiah, the Great Isaiah Scroll. How old were these manuscripts? Scientists determined the age of these manuscripts with radiocarbon dating.5 Taking the theologically motivated question seriously, they found that the text was in the Great Isaiah Scroll well before Jesus walked the earth.

  The foundation of the Christian faith is Jesus, not Adam. The four Gospel narratives tell the story of Jesus’ death on a cross. They claim he died, and then physically rose from the dead three days later. Some have wondered if Jesus did not really die on the cross; instead, he was merely unconscious. In 1986, a careful analysis of the narratives was published in a leading medical journal.6 This analysis brought new insight to the strange report that “water and blood” flowed from Jesus’ side when he was pierced with a spear (Jn 19:31-34). The analysis suggested that water could have been from abnormally collected fluid in Jesus’ chest. From modern medical science, we now know this can happen at times, even though it is rare. This detail was not inserted to satisfy a prophecy. It is strange, atypical of death by any manner, and suggests that the author was attempting to faithfully recount what was observed during Jesus’ crucifixion. Moreover, based on this observation, we can be certain it is impossible to survive a wound such as this. It is not possible the crucified man described in John was merely unconscious.

  Both these studies engaged theologically important questions with rigor and honesty. There are more examples too. Of course, not all questions can be answered by scientific means. Not all scientific answers will be acceptable to religious communities. It is, however, legitimate and expected for science to consider theologically motivated questions. Scientists, at our best, take questions seriously. Scientific inquiry can engage with theological questions, though theological agendas cannot guide scientific analysis.

  It is no surprise, therefore, that scientists have been curious about questions of Adam and Eve. More than merely a mechanical computation, science is done by scientists, and they connect their work to the cultural context in which they find themselves. This context includes stories about Adam and Eve. This has been true since before Darwin wrote Origin of the Species. Now, in the genetic age, we first learned of “Mitochondrial Eve” (Mt-eve) in January of 1987, with a widely reported study in Nature, estimating she lived about two hundred thousand years ago.7 The biblical allusion was prominent in the accompanying editorial, titled “Out of the Garden of Eden.”8 Soon after we learned of “Y-Chromosomal Adam” (Y-adam). The best estimates place him about two to three hundred thousand years ago.9 The terms pay homage to a history of parallel conversations in theology and science about our origins. These religious terms seeped into the technical language of scientists because both theology and science ask overlapping questions.

  Science is not to be guided by theological agendas. This independence, however, does not protect theological models from scientific scrutiny. Nor does this independence prohibit scientists from engaging with theological questions. In a leading scientific journal, the biologist Francisco Ayala published a study that sought to test whether or not Adam and Eve existed. He concluded no. Ayala may have ruled out one understanding of Adam and Eve.10 It would be a mistake, however, to think his work ruled out all understandings of Adam and Eve. So theologically engaged inquiry is legitimate in science. Neutrality does not, somehow, prevent science from engaging with specific theological models of human origins.

  THE TASK BEFORE US

  We can consider questions about Adam and Eve. We can consider the hypothesis that they were de novo created. We cannot, however, appeal to unattested miracles to explain away difficult pieces of evidence. Likewise, the hypothesis itself is not properly science, because science does not consider God’s action. In this exchange, therefore, we make some claims and statements that weave in and out of what “science” is and is not.

  As I understand the rules, mainstream science does not consider whether or not God exists or acts in the world. The hypothesis that Adam and Eve were de novo created arises from theology, not science, and is not a proper scientific claim or conclusion. The same is true of the Virgin Birth and the Resurrection of Jesus. In my view, none of these miracles can be proper conclusions of science. We can, nonetheless, agree that there is no scientific evidence against the Virgin Birth and the Resurrection. Science cannot come to theological conclusions. It can, however, assess evidential claims about specific theological models. Science can engage the question of whether a precise model is consistent with the evidence, barring unmentioned or ad hoc miracles. In the same way, our goal is merely to assess the hypothesis in light of evidence.

  Perhaps we will find that the de novo creation of Adam, under this hypothesis, is no different than the Virgin Birth or the Resurrection. As an example, consider the Resurrection for a moment. Yes, in every observable example, people dead in the grave for three days do not rise again. If God exists, however, there is no reason to think he did not raise one man in the distant past from the dead. If we take the Gospel narratives seriously, this baseline empirical fact is why God chose to reveal himself by raising Jesus from the dead. Only God can do such a thing. There certainly is no scientific evidence against the Resurrection. Science does not do well with singular, localized events in the distant past. In the case of the Resurrection, however, an immense amount of historical evidence points in its direction (see appendix 1). For this reason, the analogy might be closer to the Virgin Birth. We do not have genetic evidence for or against the Virgin Birth either. The only evidence we have for it is the testimony of Scripture. Whether or not we affirm the Virgin Birth is determined by whether we trust Scripture and what we think it teaches. Scientific evidence, however, does not tell us one way or another. The same may be true of Adam and Eve.

  This is the task before us. The claim that Adam and Eve, ancestors of us all, were de novo created is neither a scientific claim, nor is it a scientific conclusion. In this sense, it is an improper hypothesis. It is, nonetheless, a well-specified hypothesis that science can test with evidence. Our determination about the evidential status of this hypothesis is, moreover, a legitimate scientific claim. Many people are certain that the traditional account is incompatible with evolutionary science, but is this really the case?11 From a scientific point of view, my goal is to engage a precise theological hypothesis with careful scientific rigor. I hope for a real exchange that elucidates both theology and science. In this experiment, as we will see, there is no evidence against the de novo creation of Adam and Eve, recent ancestors of
us all. Science is silent on this matter, much as it is silent about the Virgin Birth.

  CHAPTER THREE

  GENETICS IS NOT GENEALOGY

  THE GENEALOGICAL HYPOTHESIS CONCERNS genealogical ancestry, not genetic ancestry. Adam and Eve are genealogical ancestors of everyone to the “ends of the earth” by AD 1, at the latest, but not necessarily our genetic ancestors. As the theologian C. John Collins writes,

  Swamidass’ focus on the genealogy rather than the genetics and his motivation for it is spot on: namely, the Biblical language is concerned with line of descent, or genealogy; to appeal to the genetic questions, important as they may be for some purposes, foists a misleading anachronism on the Biblical text. The same may well be true of the notion of human.1

  We will return to the notion of human later, but the distinction between genetic and genealogical ancestor is a key. Genealogical ancestry grounded in the “ordinary” language of theology and Scripture, neither of which employ the language of modern genetic science. It is also a correction to the vast majority of scientific work on Adam and Eve, which fixated on genetic ancestry instead, usually without any justification.2

  1. Genealogical ancestry concerns the connections in family trees, pedigrees, and genealogies. It is an “ordinary” definition of ancestry.

  2. Genetic ancestry, in contrast, traces the history of small stretches of DNA. Genetics is not an ordinary definition of ancestry, an anachronism in theology and Scripture.

  3. Like a streetlight and a telescope, genetic ancestry gives us a tunnel-vision view of genealogical ancestry.

  4. Mitochondrial Eve and Y-Chromosomal Adam are examples of genetic ancestry that are often misunderstood.

  The difference between these two types of ancestry is the key insight. With this distinction in mind, the scientific answer to the question of Adam and Eve shifts, quite dramatically.

  WHAT IS “GENEALOGICAL” ANCESTRY?

  Genealogical ancestry requires no scientific knowledge to explain. It traces the reproductive origin of people, matching the common use of ancestor, descendent, parent, and child. Our fathers, mothers, and grandparents are our ancestors. Going back into our history, all their grandparents are our ancestors too. In this sense, genealogical ancestry matches an ordinary understanding of ancestry.

  Scripture does not speak of DNA, but it is replete with genealogical records. Genesis 4; 5; 10; 11; 22; 25; 29–30; 35–36; and 46 all contain long lists of ancestors begetting descendants. These are all genealogical statements. Then, in Luke 3:23-28, they are extended to show how Jesus is connected by ancestry to Adam. These records were clearly important to the authors of Genesis and the New Testament. These genealogies are also obviously incomplete. Though there are exceptions, such as Eve, Cain’s wife, Esther, and Rahab, women are usually unmentioned. Similar, only one child is reported each generation, though in exceptional cases more children might be reported. Though they are incomplete, we see genealogies throughout Scripture, indicating that something is important about our connection to our ancestors.

  From a scientific point of view, genealogical ancestry is only partially recorded in genealogical records, like those in Genesis. In the context of this book, we understand genealogical ancestry as the true and complete web of biological parentage stretching back into history. Not merely our perception of the past, genealogical ancestry is actually how we each individually came into the world. Genealogical relationships only include biological parentage, but they exclude adoptive relationships. Due to infidelity, adoption, or recording errors, written genealogical records do not always follow biological parentage. Some of our genealogical history might be recorded, but certainly not all of it. Recorded genealogies are necessarily selective in what is recorded; this selectivity often defines individual and community identities.3 In truth, the unrecorded part of this history is part of our genealogy too. Genealogical ancestry includes our entire history of reproduction, including the forgotten details left out of written records. Genealogies are an unbroken chain of biological and physical relationships stretching back into the forgotten past.

  While much of our genealogical history is long forgotten, we nonetheless know that our ancestors existed. I can trace my genealogical history a few generations back. I know my parents and my grandparents. My mother remembers my great-grandparents, and perhaps some members of the generations before them. Even though I do not know who they are, I also have great-great-grandparents and great-great-great grandparents. Even without modern biology to aid me, I know that my ancestors in prior generations are real, they exist, and I can even estimate when and where they lived.

  In this way, reasoning about genealogical ancestry is not predicated on either a modern or ancient understanding of biology. This is true even if we have forgotten the identity of our ancestors. Instead, genealogies are a fundamental reality that arises among all reproducing creatures. They are the ordinary understanding of ancestry.

  WHAT IS “GENETIC” ANCESTRY?

  Genetic ancestry, in contrast, is not an ordinary understanding of ancestry. Instead of tracing individuals, it traces the history of stretches of DNA in our genomes, using recently invented technology. This is a very recent way of understanding ancestry. Of course, biological inheritance has been known and studied for a long time. Parents and children, for example, share traits with one another. For thousands of years, breeders manipulated biological inheritance to generate several different varieties of plants and animals. How exactly were “genetic” traits of parents conveyed to their offspring?4

  It is only very recently, however, that we discovered DNA, the genetic molecule of heredity. With these recent dates in mind, it is no surprise that genetic ancestry is not discussed in Scripture nor in traditional theology. Studying the genetic information stored in DNA sequences is a very new way of looking at the world. DNA was called “nuclein” when it was first extracted from surgical bandages in 1869 by Albrecht Kossel. In the early 1900s, the chemical components of DNA were isolated, and a key experiment in 1928 suggested that DNA might be the hereditary molecule conveying genetic information from generation to generation. In 1953, Francis Crick and James Watson published the double helix structure of DNA, a watershed moment in biology. The helix structure itself unlocked how it carried and copied genetic information. In structural poetry, this foundational secret of life was laid bare in DNA’s structure itself.5

  DNA is the molecule that stores and conveys inherited biological information from one generation to the next. It is composed of four chemical building blocks called “bases” that are strung together in long strands. Each of these four bases is referred to by a different letter: A, G, C, or T. Long strands of DNA store genetic information using these chemical “letters.” These strands of DNA are paired up and wound into larger structures called chromosomes. Each human cell stores a “genome,” composed of several chromosomes of different types. The “sequence” of these letters in our genomes stores information that defines much of our biology. Careful analysis of genetic sequences can uncover stories about our distant past as well.

  A historic milestone was reached just weeks after I graduated from college. In June of 2000, Francis Collins, Craig Venter, and President Clinton announced the sequencing of the first human genome. In 2005, the chimpanzee genome was published while I was a PhD student. Since then, DNA sequencing technology continues to rapidly advance, making it easier and cheaper to collect genetic information. Now the discoveries in genetic science dominate the scientific headlines. Several books have been written, and many more to come, on the lost stories recorded in our genomes.6 Scripture, however, does not mention genetics.

  Figure 3.1. Genetic ancestry is concerned with the ancestry of different pieces of DNA. The human genome has four types of chromosomes, each of which is inherited in a different way. Each chromosome includes a single strand of DNA. There are twenty-two autosomal chromosomes, and one of each is inherited from each parent. There are two sex chromosomes, and each one is i
nherited from each parent. Women have two X chromosomes, and men have one X and one Y chromosome. Everyone has one mitochondrial chromosome inherited from our mothers. The chromosomes in this figure are rendered to scale, except for the mitochondrial genome, which is just 0.0005% of the total genome in size.

  A TELESCOPE AND A STREETLIGHT

  Genetic ancestry is not genealogical ancestry. Genetic ancestry, nonetheless, gives us a view of genealogical relationships. The genetic view of our past is like a streetlight and a telescope.

  In some ways, genetic ancestry is like a streetlight, illuminating genealogical relationships in our immediate vicinity. Close relationships can be inferred from patterns in DNA, often with very high confidence. DNA tests can determine if a child’s father is her biological parent with very high accuracy, or if two children are siblings. Just a few centuries back, the genealogical relationships of individual people are outside the streetlight, much more difficult to determine from genetic information.

  In other ways, genetic ancestry is like a telescope, giving us information about populations in the very distant past. Information in this telescope, for example, causes most scientists to conclude that humans and chimpanzees share common ancestors, with very high confidence. In the intermediate range, genetics reveals an otherwise invisible history of population movements and migration over the last 10,000 years.7 Telescopes, however, block our peripheral vision. Genetic ancestry tells us about populations in the distant past, but very little about particular individuals within larger populations. Looking through a telescope, I might see the moons of Saturn and its rings, but I will be blind to my wife standing right next to me, and just about everything else.