April 05, 2012
“Copernican” Reassessment of the Human Mitochondrial DNA Tree
The supplement (the paper itself is open access). Table S5 within the supplement is very interesting, as it contains age estimates for the nodes of the new mtDNA phylogeny, and places the common mtDNA ancestor of humans (represented by the new reference sequence) at ~177,000 years.
The age of L3 (~67,000 years) is a useful sanity check of the time depth estimates, and it corresponds with the onset of Marine Isotope Stage 4. Another useful check is for that of haplogroup H (~13,000 years), consistent with a late Paleolithic origin and Neolithic expansion of this haplogroup.
The two main Eurasian macrohaplogroups M (~50,000 years) and N (~59,000 years) also appear appropriately dated on the cusp of the major Paleolithic expansion of humans across Eurasia. The higher age of N may indeed correspond to an earlier split (this haplogroup is shared by all Eurasians), whereas M has a more contained distribution (largely lacking in West Eurasians), and may have spread later. The age of haplogroup U (~47,000 years), which is the oldest West Eurasian lineage also seems to correspond appropriately to the arrival of the earliest modern humans in Europe.
Related: PhyloTree Build 14.
The American Journal of Human Genetics, Volume 90, Issue 4, 675-684, 6 April 2012 doi:10.1016/j.ajhg.2012.03.002
A “Copernican” Reassessment of the Human Mitochondrial DNA Tree from its Root
Doron M. Behar et al.
Mutational events along the human mtDNA phylogeny are traditionally identified relative to the revised Cambridge Reference Sequence, a contemporary European sequence published in 1981. This historical choice is a continuous source of inconsistencies, misinterpretations, and errors in medical, forensic, and population genetic studies. Here, after having refined the human mtDNA phylogeny to an unprecedented level by adding information from 8,216 modern mitogenomes, we propose switching the reference to a Reconstructed Sapiens Reference Sequence, which was identified by considering all available mitogenomes from Homo neanderthalensis. This “Copernican” reassessment of the human mtDNA tree from its deepest root should resolve previous problems and will have a substantial practical and educational influence on the scientific and public perception of human evolution by clarifying the core principles of common ancestry for extant descendants.