Against theistic evolutionists who insist that a single human pair is not biologically possible.
Recently, British plant geneticist Richard Buggs posted a letter he had sent in May to BioLogos’ Dennis Venema, taking issue with the claim that a population of 10,000 is required, as stated in Dennis Venema and Scot McKnight, Adam and the Genome.
Buggs never got an answer and he has since posted further thoughts at Nature: Ecology and Evolution (community):
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.
One needn’t be religious to see the importance of this question. If one pair of any sexually dimorphic life form might pass successfully through a bottleneck, ecologists need to take that fact into account.
It is a bit of a leap to say that if humans had passed through a bottleneck they would have similar levels of genetic diversity to Tasmanian devils. Whilst it seems clear that the Tasmanian devils have passed through a bottleneck, not all bottlenecks are the same. They can differ in their length as well as in their intensity, and a short bottleneck has less severe consequences than a long one. A short, sharp bottleneck is all that is needed for the Adam and Eve hypothesis.
It is easy to have misleading intuitions about the population genetic effects of a short, sudden bottleneck. For example, Ernst Mayr suggested that many species had passed through extreme bottlenecks in founder events. He argued that extreme loss of diversity in such events would promote evolutionary change. … More.
See also: Geneticist: Adam and Eve could have existed