tag:blogger.com,1999:blog-3023805782808412230.post2125636123310822244..comments2024-03-09T15:46:44.638+01:00Comments on For what they were... we are: Claim of 13 Ma Pan-Homo split Majuhttp://www.blogger.com/profile/12369840391933337204noreply@blogger.comBlogger6125tag:blogger.com,1999:blog-3023805782808412230.post-42417447633304246242014-06-29T13:22:56.807+02:002014-06-29T13:22:56.807+02:00New entry on this study: http://forwhattheywerewea...New entry on this study: http://forwhattheywereweare.blogspot.com/2014/06/pan-homo-split-11-17-million-years-ago.html (sorry for the delay).Majuhttps://www.blogger.com/profile/12369840391933337204noreply@blogger.comtag:blogger.com,1999:blog-3023805782808412230.post-68791163121981577382014-06-25T23:37:22.933+02:002014-06-25T23:37:22.933+02:00Just reading this paleo-ecological study of Neogen...Just reading this paleo-ecological study of Neogene Africa: http://horizon.documentation.ird.fr/exl-doc/pleins_textes/pleins_textes_6/b_fdi_47-48/010013166.pdf (in English)<br /><br /><i>For East Africa, studies on the Neogene fauna indicate that rain forest environments were widespread at the end of the Oligocene and in the lower Miocene (Denys et al. 1985). Various palaeobotanical data then make it possible to conclude that it is from the middle Miocene that the vegetation cover became more open, with mosaic type patterns of forest and savanna</i>...<br /><br />If we consider loss of forest cover as an evolutionary pressure to bipedalism, this is in agreement with a c. 13 Ma date for the Pan-Homo split, right in the middle of the Miocene. Chimpanzees fare badly in open lands (I watched a documentary on a clan isolated in a forest patch and they did not dare to go out almost ever) but our ape-like bipedal ancestors like Toumaï were surely much better adapted to those environments instead. <br /><br />I think that some of the data in this study also suggests a tropical forest in the early Miocene much more to the north than today, and expanding into Asia. This would explain the Africa-Indonesia span for the great ape family, which at that time would need to be almost always in forest areas. Majuhttps://www.blogger.com/profile/12369840391933337204noreply@blogger.comtag:blogger.com,1999:blog-3023805782808412230.post-80875618602199738882014-06-25T23:04:23.807+02:002014-06-25T23:04:23.807+02:00Assuming neutrality, yes. It should not surprise u...Assuming neutrality, yes. It should not surprise us: chimps do not walk, we do and so did Sahelanthropus 7 Ma ago, which also had already some of our modern brain configuration, as opposed to chimps and bonobos. But maybe some of those mutations, at least the functional ones, accumulated in bouts under selective pressure of some sort (positive selection probably, as negative selection tends to be conservative). <br /><br />Anyhow, please remember that chimps have also evolved a lot, maybe even more than our line, as suggested by <a href="http://forwhattheywereweare.blogspot.com/2013/01/chromosome-scale-evolution-among.html" rel="nofollow">a chromosomal study</a> from last year. Also chimpanzee chromosome 12 (human ref. count) seems more directly linked to the gorilla branch, so there may be the product of admixture with the proto-gorilla branch. Majuhttps://www.blogger.com/profile/12369840391933337204noreply@blogger.comtag:blogger.com,1999:blog-3023805782808412230.post-15642599390194178922014-06-25T22:24:45.661+02:002014-06-25T22:24:45.661+02:00So, naively, about 11/13th of the mutations that d...So, naively, about 11/13th of the mutations that distinguish the genus Homo from the genus Pan should already be present in Homo Erectus, which is a pretty safe bet as ancestral to all species of Homo that have left any discernable genetic trace in modern humans, Neanderthals, Denisovans, etc. andrewhttps://www.blogger.com/profile/08172964121659914379noreply@blogger.comtag:blogger.com,1999:blog-3023805782808412230.post-22898160408116793562014-06-23T19:24:49.318+02:002014-06-23T19:24:49.318+02:00Thanks. Some other readers have told me the same a...Thanks. Some other readers have told me the same and I was today finally able to find the relevant quote, which eluded me in the first reads. <br /><br />I will write something if not today, tomorrow.Majuhttps://www.blogger.com/profile/12369840391933337204noreply@blogger.comtag:blogger.com,1999:blog-3023805782808412230.post-5395079576195476702014-06-23T18:52:33.352+02:002014-06-23T18:52:33.352+02:00Indeed, this is a comment on the publication signe...Indeed, this is a comment on the publication signed, among others, by Venn and McVean.Juan Manuel Fernández Lópezhttps://www.blogger.com/profile/06607841871953018526noreply@blogger.com