Adam and Eve: lessons learned

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.

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Responding to Felsenstein, Schaffner and Harshman at The Skeptical Zone

Here is the text of a comment I posted at The Skeptical Zone in response to comments by Joe Felsenstein, Steve Schaffner and John Harshman on my Nature Ecology and Evolution blog on human bottlenecks:

Thank you all for interacting with my Nature Ecology and Evolution Community blog, and thanks to Vincent Torley for posting here. Vincent kindly sent me a personal email pointing out this thread to me and asking me to specifically interact with comments made by Steve Schaffner and Joe Felsenstein. I will also comment on John Harshman’s comments as he is making the strongest case against a bottleneck of two, which was not mentioned explicitly by Dennis Venema in his book chapter. Read More

Adam and Eve: a tested hypothesis?

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

“Abundant bioactivity” of random DNA sequences?

This blog was written for the Nature Ecology and Evolution Community where it is posted here.

Probing the claims of a recent study

Readers of this blog will be aware of the recent Nature Ecology and Evolution paper entitled “Random sequences are an abundant source of bioactive RNAs or peptides”. Rafik Neme, the first author, posted an engaging Behind the Paper blog here.

On a quick look, I thought the study might be the beginnings of the solution to the mystery of orphan genes. (I posted about orphan genes here a few months ago.) The paper appears to demonstrate that an unexpectedly high percentage of random 150 base-pair DNA sequences are functional when expressed in E. coli. If true, this would suggest that de novo gene evolution could occur easily from junk DNA. Read More