BY ANJEANETTE ROBERTS – DECEMBER 19, 2019
RTB is committed to the goal of showing exemplary character when Christians disagree with one another. We aim to do so respectfully and humbly as we pursue and help others pursue truth. Such respect and humility become especially important when we disagree on topics of importance such as how to reconcile scientific data and biblical accounts of human origins.
You may wonder how people who are committed to seeking the truth can often interpret the data so differently. The reality is that disagreement is not just an issue in science and theology but in all areas of human reasoning and worldview formation. It’s known as the underdetermination of a theory.1 People who readily acknowledge this underdetermination often qualify their acknowledgment by adding that although this is true, science (or observational or empirical data of any kind) can rule out certain theories as inconsistent with the data. Obviously this addendum is also true.
Yet, the underdetermination of theories also means that there are (and always will be) theories in obvious conflict that are, nevertheless, empirical equivalents. This means that they account for the empirical data equally but differently. Still some theories may require more ad hoc (unevidenced) assumptions or additions to fit the same data into one or more possible theories.
Applying Respectful Dialogue in Light of the Underdetermination of Theories
I recently appeared on The Language of God (LoG), a podcast produced by BioLogos and hosted by philosopher James (Jim) Stump.2 Stump interviewed several people about the topic of Adam and Eve and the scientific data supporting or challenging their existence, their relationship to our current human populations, and the dating of any possible historical progenitor pair.3 Stump did an excellent job of asking pertinent scientific and theological questions.
In an episode entitled “Adam and Eve” Stump and Deborah (Deb) Haarsma, president of BioLogos, discuss complex topics touching on science and Scripture and what each is telling us about Adam and Eve and human origins. Interspersed in their discussion are comments from the guests Stump interviewed earlier.
Together, Stump and Haarsma highlight the biggest theological issues that arise from perceived and real tensions at the interface of mainstream science and traditional biblical views. These issues include biblical authority itself, as well as accounting for the universality of human sinfulness and the image of God in humanity.
Stump acknowledges a range of perspectives on issues of how best to understand Adam and Eve in the biblical account of creation found in Genesis. He promises not to provide a definitive answer to such complex questions, but rather ways to think about the issues that help maintain a commitment to the truthfulness of God’s revelations in Scripture and in the natural world (via science). I commend him on his approach and success in clearly articulating various views.
As Stump introduces the possible ways to reconcile the biblical data with the scientific data, he offers three varying views of Adam and Eve. These are the three most prominent among possible views for considering who Adam and Eve were, and they serve as topics in the 3-chapter podcast.
- Chapter 1: Sole progenitor pair
- Chapter 2: Representative pair
- Chapter 3: Nonhistorical figures (some would say archetypical or literary)
I was pleased to participate and share my views with Stump for production of this LoG podcast. Although my views are rightly reflected, I was a bit disappointed when I listened to the podcast. Let me share why.
Sole Progenitor Pair at an Intermediate Date
In the LoG episode, three distinct ideas are conflated: (1) the sole-progenitor model of human origins, (2) “traditional” understanding of human origins, and (3) a young-earth creationist (YEC) model of human origins. This conflation obscures the fact that RTB has a tenable model of human origins which affirms traditional commitments, such as sole-progenitorship.
For brevity’s sake, I will refer to three ways to describe the dating of the sole progenitor pair: recent (less than 10-12 kya [thousand years ago]), intermediate (50-200 kya), and ancient (>450 kya). Stump and Haarsma acknowledge that the sole progenitor pair has some alternate possible datings (not just a couple constrained to YEC recent interpretations). But it is unfortunate that RTB’s sole progenitor model—with an intermediate dating for Adam and Eve—is not presented well, especially when three of the five guests might find an intermediate dating for the sole progenitor pair model much more tenable than the impression the podcast leaves.
The hosts seem to reject correlation of the data with dates (for a sole progenitor pair) younger than about 10 kya and older than about 300 kya based on general observations related to:
- Recent dating of widespread agricultural signs in the archeological record leads to rejection of dating in line with an intermediate or ancient view.
- Multiple allele frequency or allele frequency spectrum data (a measurement of population diversity based on comparing similar sites within human chromosomes)4 indicates that dates younger than 500 kya should be rejected. And according to BioLogos participant Dennis Venema, biologist at Trinity Western University, scientific analysis can’t tell us anything reliable about human origins at or beyond that 500 ky point.
- Fossil records of anatomically modern human remains, dating back 200–300 kya, indicate that more recent dating should be rejected (<10 ky).
- Claims that modern human behaviors such as use of fire date back to very early dates (circa 500 kya) lead to rejection of an early or intermediate dating.
Stump admits the complexity of the discussion, and I readily acknowledge that the BioLogos hosts cannot address all the details.
Nevertheless, the RTB model can account for all the points raised above, perhaps with some modifications to underlying assumptions. Yet the hosts do not consider the RTB model in their analysis. They present the data in support of an evolutionary interpretation of human origins, calling for a very ancient sole progenitor pair or a very recent (perhaps non-historical) Adam and Eve—neglecting and/or rejecting RTB’s model with an intermediate dating (50–200 kya) for a sole progenitor pair. We are in the process of addressing points of tension between the RTB model and mainstream science. Yet the RTB sole progenitor pair model successfully fits the scientific data and the biblical data within this intermediate range, and acknowledging this would have brought clarity to the general listener.
Interpreting Human Population Genetics
Venema addresses the genetic data, which Haarsma seems to indicate is what persuaded her not to hold an intermediate date for Adam and Eve. Unfortunately, I think the data and interpretation presented to listeners are filled with inaccuracies. Through multiple conversations over the past two years with computational biologist and founder of Peaceful Science, S. Joshua Swamidass, it has become clear to me that the perspective shared in this podcast is scientifically unsubstantiated.
Recently, in a lecture presented to the RTB scholar community, Swamidass, a Christian who affirms evolutionary science, graciously explained how the evidence against RTB’s position has been overstated. In his presentation, Swamidass explains how some of the arguments against RTB’s model have included misrepresentations of population genetics that cannot be found in the peer-review literature. For example, it was often reported that population genetics estimates of ancestral population size are the minimum population size, rather than the average population size.
However, by modeling population diversity and dynamics (with many evolutionary, mainstream scientific assumptions considered), it is possibly consistent with the evidence that our ancestral population dipped to as low as 10–20 individuals at 200 kya, and possibly to a single couple near 500 kya (or even more recently if other data is incorporated into the modeling, such as interbreeding with other hominids).
The podcast hosts don’t address these caveats and, along with Venema, repeat the unsubstantiated claim that the human population never dipped below thousands in the previous 500 ky. They agree a bottleneck less than thousands can be definitely ruled out. I think they brush aside the intermediate dating of a sole progenitor pair too quickly and without a fair representation of the data.
Disappointed but Looking Forward to Further Dialogue
To summarize, I think the hosts dismissed RTB’s intermediate sole progenitor pair position without adequate representation of the data or our model. Of course, the time constraints would not permit detailed analysis of RTB’s model nor was this the focus of the podcast. We acknowledge that some assessments of genetic data and their significance to the RTB model are works in progress. We are always ready to acknowledge when our model needs revision, and we expect some adjustments may be necessary in light of accumulating genetic data and subsequent computational analyses. We are working with Peaceful Science to examine these possibilities and refine our model as needed.
As an RTB scholar I was looking for an acknowledgement that we have an empirically equivalent model that dates a sole progenitor pair to an intermediate date, and that correlates much of the scientific and biblical data within this range. It would have given the listener a clearer understanding of options in this category. I hope the hosts will take a closer look at Who Was Adam?, the genetic data, and Swamidass’s presentation, and revise their future commentaries.
Yet despite my disappointment, I was treated with graciousness and respect on this podcast and have always been throughout my history with RTB in interactions with our colleagues at BioLogos. Certainly, none of us knows the details of God’s creation perfectly. I hope I always remember to treat others’ positions fairly and to give people the benefit of the doubt, especially when we find ourselves honestly interpreting the same data differently.
Like those at BioLogos and Peaceful Science, we at RTB are committed to continuing the conversation with respect and humility, as we engage in the intellectual exchange of possible interpretations and pursuit of the truth. As iron sharpens iron so one person sharpens another. We are looking forward to continuing the dialogue at an upcoming workshop at RTB (January 2020). And I’m looking forward to writing future blogs that share these dialogues and aspects of the RTB human origins model as they continue to develop.
- Kyle Stanford, “Underdetermination of Scientific Theory,” The Stanford Encyclopedia of Philosophy (winter 2017 edition), Edward N. Zalta (ed.), https://plato.stanford.edu/archives/win2017/entries/scientific-underdetermination/.
- In additional episodes of the Language of God you may listen and watch two discussions featuring BioLogos scientists and RTB scientists: Deb Haarsma and Hugh Ross and Darrel Falk and Fuz Rana.
- BioLogos, “Adam and Eve,” on the Language of God podcast, November 7, 2019, https://biologos.org/podcast-episodes/adam-eve.
- See “Estimating TMR4A” for explanations and calculations affecting population bottleneck sizes and dates.
NOW THAT YOU’VE DISCOVERED REASONS TO BELIEVE
Get the latest delivered directly to you by subscribing to the RTB Weekly Digest.