This blog was first posted at Nature Ecology & Evolution Community on 14 April 2018
Preliminary conclusions about the possibility of a short, sharp human bottleneck
A few months ago I asked this community if modern genome science had tested an “Adam and Eve” hypothesis that the human lineage has passed through short, sharp bottleneck of two at some point in its history. While this question may sound bizarre to some, it is one that is often asked by those with a background in Abrahamic faiths. My post has therefore been taken up and discussed extensively on the Skeptical Zone and Biologos Forum over the past few months, as well as by various blogs.
The claim that genomic methods have been used to test and reject an “Adam and Eve” hypothesis was central to the recent book Adam and the Genome. My post, which critiqued the arguments made in that book, has received a broad level of explicit or tacit agreement in subsequent online discussions. More adequate ways of testing the hypothesis have been suggested, and preliminary results have been obtained.
Here I will share some of the lessons I have learned from these discussions and from further reading. These are somewhat tentative, and not all are based on published peer reviewed literature. In a short blog I cannot do not do full justice to all the contributions that have been made by various scientists within the online fora, so as far as possible I will try to provide direct links to the contributions of others.
This is Part 1 of my response to Dr Dennis Venema’s second Biologos Blog “Adam, Eve and Population Genetics: A Reply to Dr. Richard Buggs (Part 2)”. Dr Venema was responding to my blog at Nature Ecology and Evolution Community about his book Adam and the Genome. Since Dr Venema’s Part 1 blog responding to me, a vigorous debate has been ongoing on the Biologos Forum here. This debate is now beginning to come to a conclusion, so I have a bit of time to respond to the Part 2 blog by Dennis, which branched out from the Forum debate. Here is Part 1 of my response.
This is my response to Dennis Venema’s Biologos blog that he posted after I published my email and blog at Nature Ecology and Evolution Community about his book Adam and the Genome. This text is also placed as a comment under Dr Venema’s blog post on the Biologos blog page.
I am glad that we are now establishing a dialogue about the scientific credibility of a bottleneck of two at some point in the history of the human lineage. I am hoping that during the course of this discussion we will be able to examine in detail the claims that you make in chapter three of Adam and the Genome, and that you will respond to all the critiques and questions that I have raised in my email to you and my blog at Nature Ecology and Evolution Community.
This blog was written for the Nature Ecology and Evolution Community where it is posted here.
Comments on a recent book chapter
Does genomic evidence make it scientifically impossible that the human lineage could have ever passed through a population bottleneck of just two individuals? This is a question I am asked semi-frequently by religious friends. With my current understanding of the genetic evidence, I can’t state categorically that it’s impossible. In this view, I find I differ from a recent book chapter on the topic. I’m writing this blog to run my thoughts past other biologists, and check I am not missing something. Read More
A few months ago, I was reading a new book by Dennis Venema and Scot McKnight entitled Adam and the Genome. I was surprised to find a claim within the book that the past effective population size of humans has definitely never dropped below 10,000 individuals and that this is a fact of comparable scientific certainty to heliocentrism. I emailed Dennis Venema, the biologist author of the book, to query this. Unfortunately, he has not yet responded. I therefore remain unconvinced that it is a scientific impossibility for human beings to have all descended from a single couple. If I am wrong, though, I would like to know. I therefore post my email here, in hopes of garnering responses to my objections. Read More