An “In Press Corrected Proof” of
a paper by Cosimo Posth et. al (1), released last week had an enormously
shocking (to me at least!) statement in its summary.
Here is that summary with the
true shocker in bold - the emphasis is of course mine.
“Summary
How modern humans dispersed into Eurasia and Australasia, including the
number of separate expansions and their timings, is highly debated [ 1, 2 ].
Two categories of models are proposed for the dispersal of non-Africans: (1)
single dispersal, i.e., a single major diffusion of modern humans across
Eurasia and Australasia [ 3–5 ]; and (2) multiple dispersal, i.e., additional
earlier population expansions that may have contributed to the genetic
diversity of some present-day humans outside of Africa [ 6–9 ]. Many variants
of these models focus largely on Asia and Australasia, neglecting human dispersal
into Europe, thus explaining only a subset of the entire colonization process
outside of Africa [ 3–5, 8, 9 ]. The genetic diversity of the first modern
humans who spread into Europe during the Late Pleistocene and the impact of
subsequent climatic events on their demography are largely unknown. Here we
analyze 55 complete human mitochondrial genomes (mtDNAs) of hunter-gatherers
spanning ∼35,000 years
of European prehistory. We unexpectedly
find mtDNA lineage M in individuals prior to the Last Glacial Maximum (LGM).
This lineage is absent in contemporary Europeans, although it is found at high
frequency in modern Asians, Australasians, and Native Americans. Dating the
most recent common ancestor of each of the modern non-African mtDNA clades
reveals their single, late, and rapid dispersal less than 55,000 years ago.
Demographic modeling not only indicates an LGM genetic bottleneck, but also
provides surprising evidence of a major population turnover in Europe around
14,500 years ago during the Late Glacial, a period of climatic instability at
the end of the Pleistocene.”
But it doesn’t end there.. oh no!
Or should I rather shout yes, yes, YES!
From the Results and Discussion
section we also have:
“However, whereas present-day Asians, Australasians, and Native
Americans carry both M and N mtDNA hgs.”
As most bloggers interested in the
peopling of the Americas will know, the accepted mtDNA haplogroups found in the
pre-Colombian population have been limited to A, B, C, D and X and one case of
mtDNA M in a mid-Holocene burial from China Lake, British Columbia (Malhi et.
al. 2007 (2)), so this would be BIG news.
I’ll update this post when I have closely read every sentence of the paper and supporting materials.
Let’s hope it’s not me going off
my trolley or the authors making a huge error!
Update 24th of February
Apologies for nearly for wetting myself with excitement over the wording of Posth et. als paper.
Let me explain, after reading it several times I had doubts that it meant what I thought it meant: Haplogroups M and N are found in America.. I thought I had missed some major paper.
However just to check I posted on several genetics forums that had discussions on the paper. The replies I had were polite and explained what I had suspected Posth et al meant the lineages descended from haplogroups M and N i.e. the A, B, C, D and X of Native Americans.
Here are some of my postings and the thoughtful replies:
Here's the one from the Molecular Ecologist
References
1. Posth, C. 2016. Pleistocene Mitochondrial Genomes Suggest
a Single Major Dispersal of Non-Africans and a Late Glacial Population Turnover
in Europe.In Press Corrected Proof Current Biology. Retrieved from:
http://www.cell.com/current-biology/fulltext/S0960-9822(16)00087-7
Pdf download at:
For a totally hilarious exchange see here! All I can say regarding this one is that it just goes to prove that the arrogant, opinionated and unreasonable of the 'real' world are found in fairly rarefied world of genetics discussion boards.. Go on click.. it really REALLY is worth a read.
ReplyDeleteAll I can say regarding that exchange is what a fool you are to equate me to mooreisbetter and to some other person with the name Onur.
Dear 'Onur', thank you for your, as usual, well-thought-out response. NeilB
Delete