Chromosomal inversions and the reproductive isolation of species. Chromosomal Speciation and Molecular Divergence--Accelerated Evo. Humans and their closest evolutionary relatives, the chimpanzees, differ in ∼1.24% of their genomic DNA sequences. The fraction of these changes accumulated during the speciation processes that have separated the two lineages may be of special relevance in understanding the basis of their differences.
We analyzed human and chimpanzee sequence data to search for the patterns of divergence and polymorphism predicted by a theoretical model of speciation. According to the model, positively selected changes should accumulate in chromosomes that present fixed structural differences, such as inversions, between the two species. Protein evolution was more than 2.2 times faster in chromosomes that had undergone structural rearrangements compared with colinear chromosomes. Proceedings of the National Academy of Sciences. Feschotte Lab. The Beauty of Reptilian Genomes This magnificient creature on the left is a copperhead. Copperheads are very common around Arlington.
I found this fortunate, but not everybody agrees. Anyhow, this month we co-authored three papers that illustrate how fascinating these and other reptiles are when it comes to their genomes too. On this I hope everybody will agree. The first paper , spearheaded by Todd Castoe and David Pollock at the University of Colorado Health Sciences Center, uses next-gen sequencing to carry out a comparative analysis of the repetitive DNA landscape of two celebrated snakes, the copperhead and the Burmese python . The second paper reports the result of a large-scale screen to detect SPIN transposons in non-avian reptiles conducted by postdoc Clement Gilbert and a bunch of talented undergrads. The third paper summarizes the effort of the recently established Snake Genomics Consortium to produce a whole genome sequence for the Burmese python, led by Todd and David.