![]() The GenBank database contains at present only two complete mitochondrial genomes from Gorilla gorilla, two from Pan troglodytes and only a single mitochondrial genome from Pan paniscus. While several thousand complete mitochondrial genomes from various modern human populations are available to date and complete mitochondrial genomes of six Neandertal individuals have been recently sequenced, the number of available individual mitochondrial sequences is very limited in non-human hominid species. The complete mitochondrial genome sequences of hominid species have been known for a while and were frequently used in studies aiming to understand important aspects of human evolution. Thus, we hypothesize that the species-specific release of evolutionary constraints for the mitochondrial genes of the proton-translocating ATPase is a consequence of altered heat homeostasis in modern humans. Some variants of mitochondrially encoded subunits of the ATPase complex in humans very likely decrease the efficiency of energy conversion leading to production of extra heat. While in bonobos this complex showed a similar low value as complexes I and IV, human haplogroups displayed 2.2 to 7.6 times increased d N /d Sratios when compared to bonobos. (ii) A comparison of the ratios of non-synonymous to synonymous changes ( d N /d S) among polymorphic positions in bonobos and in 4902 Homo sapiens mitochondrial genomes revealed a remarkable difference in the strength of purifying selection in the mitochondrial genes of the F 0F 1-ATPase complex. This indicates that at least a part of the unstable sites of the mitochondrial genome is species-specific and difficult to be explained on the basis of a mutational hotspot concept. ![]() nucleotide changes that occurred independently on separate branches of the phylogenetic tree, 13 were not homoplasic in humans. When comparing spectra of polymorphic mtDNA sites in bonobos and humans, we observed two major differences: (i) Of all 31 bonobo mtDNA homoplasies, i.e. ![]() Incidentally, we discovered that the current reference sequence for bonobo likely is a hybrid of the mitochondrial genomes of two distant individuals. We identified three major clades among bonobos that separated approximately 540,000 years ago, as suggested by Bayesian analysis. ![]() We have analyzed the complete mitochondrial genomes of 22 Pan paniscus (bonobo, pygmy chimpanzee) individuals to assess the detailed mitochondrial DNA (mtDNA) phylogeny of this close relative of Homo sapiens. ![]()
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