Adam and Eve have never been so hot since the days everyone went to church. At least not to judge from the current Bottleneck War in genetics.
It was sparked by British geneticist Richard Buggs pointing out in a journal that, strictly speaking, one fertile human pair could survive a bottleneck (Adam and Eve more or less, fig leaves optional). At first, he didn’t get mail. Then he got mail. Yesterday, we reported that Buggs (the Yes guy) was asking geneticist Dennis Venema (the big No guy) to provide sources for some claims. Over to Venema.
Meanwhile, physicist Lee Spetner, author of The Evolution Revolution, writes to say that adaptability is built into organisms by transposable elements and thus assumptions about merely random mutation are wrong:
The arguments about bottlenecks and diversity of alleles are all badly misinformed. The arguments are predicated on the assumption that genetic diversity comes from random mutations in the DNA, which is not true. Most genetic diversity comes not from random point mutations but from the activity of transposable elements (e. g., Kidwell and Lisch 2000, van de Lagemaat et al. 2003, Britten 2010), which are nonrandom. It turns out that environmental stress triggers the endocrine glands to secrete hormones that in turn trigger transposable elements that tend to produce phenotypic changes that relieve the stress yielding an adaptive response to a new environmental condition. This capability is built-in to the organism and is designed to permit the organism to adapt to a variety of environment. Therefore any conclusions about genetic diversity on the assumption that it is produced only by random mutations are wrong.
He offers the following links: Transposable elements in mammals promote regulatory variation and diversification of genes with specialized functions. Trends in Genetics 19 (10): 530–536. van de Lagemaat, Louie N. et al. (2003) (paywall)
Kidwell, M. and D. Lisch (2000) Transposable elements and host genome evolution. TREE 15 (3): 95-99. (paywall)
Britten, Roy J. (2010) Transposable element insertions have strongly affected human evolution Proceedings of the National Academy of Sciences of the United States of America 107 (46): 19945-19948 (public access)
Keep your scorecard handy.
See also: Are Adam and Eve genetically possible? The latest: Richard Buggs (yes) replies to Dennis Venema (no): I realise that some of your non-biologist readers may think I am being rather pedantic in asking for a citation when you are making what appears to be a very straightforward case from allele numbers. But biologist readers will know that very few things in this area are straightforward, and without a citation I have to treat your claims as unsubstantiated.
Adam, Eve, Richard Buggs, and Dennis Venema: Could Adam and Eve have existed?
Geneticist defends possible Adam and Eve in Nature: Ecology and Evolution
Geneticist: Adam and Eve could have existed