The only reference I found to anything older was a genetic article using molecular clock to put the date of divergence of
H. neander DNA from
H. sapiens DNA at over 300K years, but I don't trust the dates of those clocks at that kind of projection.
Just a moment...PNAS Vol. 96, Issue 10, 5581-5585, May 11, 1999
quote:
The date of divergence between the mtDNAs of the Neandertal and contemporary humans is estimated to 465,000 years before the present, with confidence limits of 317,000 and 741,000 years.
Dates of Divergences. For the estimation of the ages of MRCAs of different groups of mtDNAs, the observed nucleotide differences were corrected for multiple substitutions by using the Tamura-Nei algorithm (17). The resulting genetic distances and the estimated age of the modern human-chimpanzee split of 4-5 million years (22, 23) were used to calculate the substitution rate of 0.94 10-7 substitutions per site per year per lineage with 5.92 10-8 and 1.38 10-7 as the lower and upper confidence limits. These estimates are in reasonable agreement with previous rate estimations for the mtDNA control region (32, 33). Using these rates, the age of the MRCA of the Neandertal and modern human mtDNAs was estimated to be 465,000 years, with confidence limits of 317,000 and 741,000 years. This age is significantly older than that of the MRCA of modern human mtDNAs, which, by the same procedure, was determined to be 163,000 years, with 111,000 and 260,000 years as confidence limits. Finally, the age of the MRCA of the mtDNAs of the seven chimpanzees and the two bonobos was calculated as 2,844,000 years (confidence limits: 1,940,000 and 4,534,000 years).
Of course that could also mean that there were one or two species and other members of the
Homo clade between the common ancestor pool and either
H. neander or
H. sapiens, not that each species necessarily extends back that far -- for instance they imply that
Homo sapiens starts at 163K years ago -- while actual fossil information pushes that to 200K:
Ethiopia is top choice for cradle of Homo sapiens : Nature News
quote:
Radioactive dating finds that fossil skulls are 195,000 years old.
Two Ethiopian fossils have been crowned as the oldest known members of our species. An estimated 195,000 years old, the pair were witness to the earliest days of H. sapiens .
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Taking this genetic information as an indication of relative dating (which is as far as I trust it, but where I think it is valid) this means that the divergence of Neander ancestors from
H. sapiens ancestor occurred after hominids diverged from chimpanzees, but before
H. sapiens ancestors diverged from
Homo heidelbergensis
ie - that we are at least cousins once removed from
H. neander relations rather than first cousins.
It would also mean that this diagram
http://www.handprint.com/LS/ANC/evol.html(Last revised 08.17.2007 ” © 2007 Bruce MacEvoy)
Is more accurate than the one I posted earlier
Anthropology | Smithsonian National Museum of Natural History(Last revised unknown)
... in this area. It also goes back to almost 400K for
H. neander, but then it says the reason is:
quote:
” Time spans for modern humans, Neanderthals and archaic H. sapiens (H. heidelbergensis) have been extended back beyond accepted fossil limits to accommodate recent genetic evidence that the divergence between the Neanderthal and human lines occurred around 500,000 years ago.
Sorry, but I trust hard fossil dates much more than extrapolated genetic ones. The tree by the Smithsonian Institute appears to be based on fossils, not genetic "dates" ... which gets us back to ~200K for
H. neander fossils .... sigh.
Enjoy.
Edited by RAZD, : consistent nomenclature
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