Topic - Homo

Homo (Latin homō "human being") is the genus which emerged in the otherwise extinct Australopithecus genus that encompasses the extant species Homo sapiens (modern humans), plus several extinct species classified as either ancestral to or closely related to modern humans (depending on a species), most notably Homo erectus and Homo neanderthalensis.The genus is taken to emerge with the appearance of Homo habilis, just over two million years ago. Genus Homo, together with the genus Paranthropus is probably sister to A. africanus in the genus Australopithecus, which itself had previously split from the lineage of Pan, the chimpanzees."Patterson et al. suggest that the apparently short divergence time between humans and chimpanzees on the X chromosome is explained by a massive interspecific hybridization event in the ancestry of these two species. However, Patterson et al. do not statistically test their own null model of simple speciation before concluding that speciation was complex, and—even if the null model could be rejected—they do not consider other explanations of a short divergence time on the X chromosome. These include natural selection on the X chromosome in the common ancestor of humans and chimpanzees, changes in the ratio of male-to-female mutation rates over time, and less extreme versions of divergence with gene flow. I therefore believe that their claim of hybridization is unwarranted." see current estimates regarding complex speciation.--> - Source: Wikipedia