Would Marcus Ross Come Reason With Me?

If Dr. Marcus Ross has any scientific objections to my work, let him to take them up directly with me.

Dr. Marcus Ross is a young earth creationist, a paleontologist, and a friend of mine. His voice is important. I am pleased to see he is contributing to a four views book on Adam and Eve, along with Andrew Loke, William Lane Craig, and Kenton Sparks. I often recommend Ross as a speaker to those looking to include young earth creationists. But, if Ross has any scientific objections to my work, let him to take them up directly with me.

Is Evolution Compatible with Genesis?

This last weekend I was at a conference that included a debate, between Michael Jones and Ross. The question: Is Evolution Compatible with Genesis?

This question leads to an asymmetric debate, one which Ross is bound to lose. There are many many ways to read Genesis consistent with evolution. To successfully argue for incompatibility, Ross must demonstrate each and every one of these interpretations is wrong. This is a very difficult task to accomplish. Even if one particular reading of Genesis fails, there is a multiverse full of more readings to contend with too. Each and every one of them must be dispatched to declare that “evolution is not compatible with Genesis.”

A more interesting debate would be symmetric, a fair fight. Granting from the outset that Genesis can be compatible with evolution, the question could be whether young earth creationism was more compatible with Genesis than readings of Genesis that allow for evolution. This, at least, would put both sides on even footing. It seems, however, many creationists are not ready yet to grant evolution can be compatible with Genesis.

Still, I was pleased to see Jones use my book to make his case (at 18:17),

Joshua Swamidass, who’s here with us, today put out a book which, in my view, put the final linchpin in making the case that Christianity and Evolution are compatible. He’s demonstrated through computer models and genetic studies that everyone by one would have common ancestors that only lived a few thousand years before this. It can be shown all people alive today would be genealogically connected to one couple in the Middle East, just a few thousand years ago. So everyone alive today, due to cross-cultural interbreeding, are all related and share a common ancestor.

This finding is explained in detail in my book, so I will not elaborate it here.

The Scientific Objection

Towards the end of the debate, in the Q&A, Ross lobbed a scientific objection in my direction (at 1:41:13),

The mathematical modeling that Josh uses in The Genealogical Adam & Eve doesn’t work. And that the most recent modeling for genealogical models would only allow a universal ancestor to all of humanity somewhere between 50 and 100 thousand years ago, not a few thousand years ago. You can read that in the paper by Kelleher et. al. 2016. It’s cited in Josh’s book.

There was quite a stir. Of course, I was not a participant in the debate, so I had no opportunity to respond. Afterwards, Sy Garte, a biologist, asked me what Ross was getting at and if there was an error in my work.

The Rebuttal in 2020

To answer Garte, I pointed to my written response to Ross in 2020. Turns out, this is not a new objection. In fact, Ross first raised this precise objection back in 2020, in his response to my book in Sapientia. And two years ago, I responded with this rebuttal,

Second, Ross objects that Kelleher et al. (2016) “directly contradicts” my scientific conclusions. Ironically, this second objection undermines the first, clarifying that my scientific claims are falsifiable, at least in principle.1 Moreover, I explained this study’s findings at length, citing it five times (pp. 45, 48, 51, 53, and 59). This study considers a counterfactual world in which our ancestors travel only a few kilometers over the course of their entire lifetimes. In this imaginary world, I agree that universal ancestors take more than 100,000 years to arise. But in the real world, we easily transverse a few kilometers in merely a thirty-minute stroll. Moreover, the genetic evidence demonstrates unequivocally that our real history includes very long-range migration across oceans and between continents (ch. 6), causing universal ancestors to arise in just a few thousand years.

I invite Ross to clarify why he disagrees. His objections are a paradox. If either objection were valid, Ross’s own belief in young earth creationism would be challenged. Does he really think our ancestors were restricted to just a few kilometers of migration in their whole lifetimes?

The key information in this rebuttal is already in the book. As I explained in the book, we care about the most relevant publications, not merely the most recent. Ross never disputed the factual content of this rebuttal, nor has he published a written response to it.

One point in my rebuttal does extend beyond the book’s content. Ross’s argument is self-defeating—undermining his own young earth creationism—leaving him on very shaky ground. For a given amount of migration, the spread of genealogical ancestry within an existing human population (i.e. a genealogical Adam and Eve) will always be faster than the geographic spread of a population without interbreeding (i.e. Ross’s young earth creationism). So Ross’s argument against The Genealogical Adam and Eve, if it were legitimate, would easily be flipped into an argument against his own position.

For most scientists, this rebuttal settles the matter entirely. I thought the rebuttal had settled the matter for Ross too.

Come Reason With Me

As a scientist, I do my best to accurately represent the evidence. I also know I will make mistakes. It is for this reason that I take objections to my scientific work very seriously. I know that other scholars will identify problems, and even mistakes, that merit correction. At the same time, I expect objection to be raised in good faith.

The exchange in Sapientia gave me the last word, but I still want to accurately represent the science, even if that means acknowledging where I made a mistake. So I invited Ross to publicly clarify his objections, expecting that he would concede the point or engage my rebuttal. Ross never took me up on this invitation.

The next year at a creationist conference, in late 2021, Ross debated me directly on The Genealogical Adam & Eve. In front of this audience, so very friendly to him, Ross could have raised his objection, responded to my rebuttal, and taken me to task on the science. If his objection was well-grounded, I am sure Ross would have done so.2 He did not.

After the debate, Ross did privately discuss his objection with me, asking some follow up questions.3 I clarified what the genetic evidence showed, and I explained the rebuttal further to him. It was my understanding that this private discussion settled the matter entirely. In case there remained any doubt, I again invited Ross to write down and publish a response to my rebuttal. He did not.

Now two years after my rebuttal, while engaging a non-scientist in a debate, Ross raises the same objection again? Ross neither acknowledged nor addressed the substance of my rebuttal. This is not fair play.

There is no reason to argue by proxy with the scholars who rely upon my work. Peaceful Science is still willing to publish an article in which Ross may lay out in full detail his response to my rebuttal.

I am here. Come reason with me.

If there is any substance to this objection, let us see Ross’s written response to my rebuttal.


J. Kelleher, et. al. Spread of pedigree versus genetic ancestry in spatially distributed populations. Theoretical Population Biology, 2016. https://doi.org/10.1016/j.tpb.2015.10.008

Marcus Ross, Hedges Around His Garden Sapientia, 2020.

S. Joshua Swamidass, The Genealogical Adam and Eve: A Rejoinder Sapientia, 2020.

S. Joshua Swamidass, The Genealogical Adam and Eve, 2019.

    Aug 9, 2022
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