Evolution of the X chromosome

This week's Nature has an article summarizing the sequencing of the human X chromosome by Ross et al. (that should be Ross ET AL.!!!; see the author list at the end). There is an impressive wealth of quantitative and genetic detail here, but I'm not going to reiterate it. Mostly, I want to outline the evolutionary story.

And it really is an obligate evolutionary story they're telling. A paper on the sequence of a chromosome is not just a recitation of As, Gs, Cs, and Ts—it is about extensive analyses, comparisons of genomes from different species, reconstructions of past translocations, inversions, and mutations, and about the logical and mathematical modeling of the history of transformations that produced a particular arrangement of genes. What we have in the X chromosome is a text that shows the smudges and strike-outs and rearrangements of hundreds of millions of years of editing.

Continue reading "Evolution of the X chromosome" (on Pharyngula)