Wednesday, November 11, 2009

Last week in Science

My weekend blog fast prevented me from noting two interesting pieces in last week's issue of Science. First was an extra-snarky review of David Prindle's book Stephen Jay Gould and the Politics of Evolution written by Vassiliki Betty Smocovitis. Read the whole review, and you get the idea that the book is less than ideal in its treatment of its subject, but that doesn't stop Smocovitis from using the review as a platform to vent a bit of frustration:
Stephen Jay Gould and the Politics of Evolution arrives just in time. Just when it looked like the "ultra-Darwinists" were winning the "year of Darwin" with their interminable love-fests, triumphalist narratives, and self-serving revisionist histories; when we were starting to think that Darwin was the only evolutionist to have lived in the past 150 years; and when we might conclude that nearly the entire evolutionary community had drunk the Kool-Aid of antiquarian Darwinism, David Prindle's book appears to give us pause.
Kool-Aid of antiquarian Darwinism? Very subtle.

Meanwhile, remember those days not so long ago when genome sequencing was big news and usually made the cover of Nature or Science? With people talking about 10,000 genomes now, the new horse genome appeared on the scene nearly unnoticed with just a three-page letter. The problem is that the horse genome is a lot like every other mammalian genome already published. Similar size, similar repeat content, similar gene count. What is interesting is the novel centromere on chromosome 11 that doesn't have any of the satellite repeats that mark typical mammalian centromeres. Apparently, centromeres can spontaneously arise without a proliferation of associated repeat sequences. How this happens we do not know.

Also of interest in the horse genome is the fact that "We were unable to phylogenetically separate E. przewalskii from the domesticated horses, despite its different karyotype (2N = 66 versus 2N = 64 for the domesticated horse)." Przewalski's horse (E. przewalskii) is thought to be either a horse lineage that has continued to hybridize with the domesticated horse or a lineage only recently emerged from the domesticated horse. Note the different chromosome numbers. In the context of human chromosome 2, we often hear creationists claim that such chromosomal fusion or fission events are bad and don't happen. Przewalski's horse shows us that such chromosomal rearrangements are quite possible. What that means for the origin of human chromosome 2 I do not know.

Smocovitis. 2009. Darwin is dead - long live evolution. Science 326:800-801.>

Wade. 2009. Genome sequence, comparative analysis, and population genetics of the domestic horse. Science 326:865-867.