The gorilla genome has been sequenced and yields some interesting insights on human evolution. The research is reported in Nature. The article is open access. Here is the abstract:
Gorillas are humans’ closest living relatives after chimpanzees, and are of comparable importance for the study of human origins and evolution. Here we present the assembly and analysis of a genome sequence for the western lowland gorilla, and compare the whole genomes of all extant great ape genera. We propose a synthesis of genetic and fossil evidence consistent with placing the human–chimpanzee and human–chimpanzee–gorilla speciation events at approximately 6 and 10 million years ago. In30%of the genome, gorilla is closer tohuman or chimpanzee than the latter are to each other; this is rarer around coding genes, indicating pervasive selection throughout great ape evolution, and has functional consequences in gene expression. A comparison of protein coding genes reveals approximately 500 genes showing accelerated evolution on each of the gorilla, human and chimpanzee lineages, and evidence for parallel acceleration, particularly of genes involved in hearing.Wealso compare the western and eastern gorilla species, estimating an average
sequence divergence time 1.75 million years ago, but with evidence for more recent genetic exchange and a population bottleneck in the eastern species. The use of the genome sequence in these and future analyses will promote a deeper understanding of great ape biology and evolution.
Afarensis: Anthropology, Evolution, and Science 
Oooh. Very interesting indeed, I’ll have to take a look at this paper. Thank you for posting on it.
Recently I have been contemplating the human X chromosome and it’s striking similarity to the chimpanzee one. Prof. Colin Groves here at the ANU has suggested to us that it was possibly due to interbreeding early after the split between Pan and Homo. This resulted in the male hybrids being sub-fertile but the hybrid females coming to dominate the lineage thereafter through some selective advantage or another. Essentially the ‘original’ Homo X chromosome was replaced by the Pan one. Any thoughts?
Unfortunately, that is not an issue I am very familiar with, although it sounds like he is referring to the article by Patterson et al on complex speciation in humans and chimps.
The hybridization theory for why the X chromosomes are so similar between humans and chimps is indeed from the Patterson et al paper in Nature from 2005.
It is certainly a possibility. When inferring the effective population size of ancestral species we usually find a very large number for the human and chimp ancestor which could be explained by a structured population, or two separated species with some admixture, similar to what we have found between humans and neanderthals and Denisovans. We also see gene flow between the different gorilla species in the new gorilla paper and we saw gene flow between the orangutan species in the orangutan genome paper from last year.
It is not the only explanation, though. If selection works stronger on X than on the autosomes you would also get more similar X chromosomes. We looked at this a bit in the gorilla genome paper, and we have seen this in central chimpanzees as well (see this PNAS paper: http://www.pnas.org/content/early/2012/01/18/1106877109.abstract)
Yeah, I did some searching and found the PNAS article, haven’t read it yet though. I also stumbled across Takahasi and Innan 2008 Inferring the Process of Human–Chimpanzee Speciation which bears on the issue as well. There is also a critique of the Patterson et al paper (as well as their response) by Wakely.
Yeah, there are lots of papers on this, but as far as I can tell the jury is still out on this 🙂
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