Thu, 21 Aug 2008 14:15:39 BST CiteULike: usagi-kirin's Fischer http://www.citeulike.org/user/usagi-kirin/author/Fischer CiteULike.org en-gb Copyright © 2004-2008 citeulike.org http://www.citeulike.org/user/usagi-kirin/article/2141217 <i>Current Biology, Vol. 16, No. 11. (6 June 2006), pp. 1133-1138.</i><br /><br />Summary Comparisons of genetic variation between humans and great apes are hampered by the fact that we still know little about the demographics and evolutionary history of the latter species 1, 2, 3 and 4. In addition, characterizing ape genetic variation is important because they are threatened with extinction, and knowledge about genetic differentiation among groups may guide conservation efforts [5]. We sequenced multiple intergenic autosomal regions totaling 22,400 base pairs (bp) in ten individuals each from western, central, and eastern chimpanzee groups and in nine bonobos, and 16,000 bp in ten Bornean and six Sumatran orangutans. These regions are analyzed together with homologous information from three human populations and gorillas. We find that whereas orangutans have the highest diversity, western chimpanzees have the lowest, and that the demographic histories of most groups differ drastically. Special attention should therefore be paid to sampling strategies and the statistics chosen when comparing levels of variation within and among groups. Finally, we find that the extent of genetic differentiation among "subspecies" of chimpanzees and orangutans is comparable to that seen among human populations, calling the validity of the "subspecies" concept in apes into question. Demographic History and Genetic Differentiation in Apes Anne Fischer Joshua Pollack Olaf Thalmann Birgit Nickel Svante Paabo doi:10.1016/j.cub.2006.04.033 Current Biology, Vol. 16, No. 11. (6 June 2006), pp. 1133-1138. 2007-12-18T14:55:51-00:00 2006 Current Biology 16 11 1133 1138 2008_gorilla-y http://www.citeulike.org/user/usagi-kirin/article/2619682 <i>Mol Biol Evol, Vol. 21, No. 5. (May 2004), pp. 799-808.</i><br /><br />To characterize patterns of genomic variation in central chimpanzees (Pan troglodytes troglodytes) and gain insight into their evolution, we sequenced nine unlinked, intergenic regions, representing a total of 19,000 base pairs, in 14 individuals. When these DNA sequences are compared with homologous sequences previously collected in humans and in western chimpanzees (Pan troglodytes verus), nucleotide diversity is higher in central chimpanzees than in western chimpanzees or in humans. Consistent with a larger effective population size of central chimpanzees, levels of linkage disequilibrium are lower than in humans. Patterns of linkage disequilibrium further suggest that homologous gene conversion may be an important contributor to genetic exchange at short distances, in agreement with a previous study of the same DNA sequences in humans. In central chimpanzees, but not in western chimpanzees, the allele frequency spectrum is significantly skewed towards rare alleles, pointing to population size changes or fine-scale population structure. Strikingly, the extent of genetic differentiation between western and central chimpanzees is much stronger than what is seen between human populations. This suggests that careful attention should be paid to geographic sampling in studies of chimpanzee genetic variation. Evidence for a complex demographic history of chimpanzees. A Fischer V Wiebe S Pääbo M Przeworski Mol Biol Evol, Vol. 21, No. 5. (May 2004), pp. 799-808. 2008-04-01T12:58:19-00:00 2004 Mol Biol Evol 0737-4038 21 5 799 808 2008_gorilla-y http://www.citeulike.org/user/usagi-kirin/article/998680 <i>Mol Biol Evol, Vol. 24, No. 1. (1 January 2007), pp. 146-158.</i><br /><br />Relatively little is known about the evolutionary and demographic histories of gorillas, one of our closest living relatives. In this study, we used samples from both western (Gorilla gorilla) and eastern (Gorilla beringei) gorillas to infer the timing of the split between these geographically disjunct populations and to elaborate the demographic history of gorillas. Here we present DNA sequences from 16 noncoding autosomal loci from 15 western gorillas and 3 eastern gorillas, including 2 noninvasively sampled free-ranging individuals. We find that the genetic diversity of gorillas is similar to that of chimpanzees but almost twice as high as that of bonobos and humans. A significantly positive Fu & Li's D was observed for western gorillas, suggesting a complex demographic history with a constant, long-term population size and ancestral population structure. Among different population-split scenarios, our data suggest a complex history of western and eastern gorillas including an initial population split at around 0.9-1.6 MYA and subsequent, primarily male-mediated gene flow until approximately 80,000-200,000 years ago. Furthermore, simulations revealed that more gene flow took place from eastern to western gorilla populations than vice versa. 10.1093/molbev/msl160 The Complex Evolutionary History of Gorillas: Insights from Genomic Data O Thalmann A Fischer F Lankester S Paabo L Vigilant doi:10.1093/molbev/msl160 Mol Biol Evol, Vol. 24, No. 1. (1 January 2007), pp. 146-158. 2006-12-17T13:21:23-00:00 2007 Mol Biol Evol 24 1 146 158 2008_gorilla-y