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One "detail" that seems quite important when analyzing the structure of human dispersal are those moments of sudden very dynamic expansiveness that leave a mark in form of star-like structure, that is when many subclades diverge from a common core node. This is a clear signature of very rapid expansion.
Following the phylogeny, I can detect the following star-like structures in human mtDNA:
Large stars:
These are only two: M and H.
M has 43 basal sublineages and surely signals the beginning of the Great Eurasian Expansion after the out of Africa episode.
H has 34 basal sublineages and may signal the colonization of Europe arguably.
Medium stars:
There are three star-like structures with 15-16 sublineages. These are R, H1 and D4.
R has 16 basal sublineages and seems to mark the final episode of the Great Eurasian Expansion.
H1 has 15 basal subclades and would seem to be the largest continuation of the H expansion in Europe.
D4 has 16 basal subclades and would indicate, along with other lineages the colonization of NE Asia and eventually America as well.
Additionally, macro-haplogroup N, with 12 branches, can also be considered in this group, participating in the Great Eurasian Expansion, along with its "sister" M and its "daughter" R.
Small stars:
I arbitrarily decided that the smallest size for a star-like structure in this mini-research would be of 5 sublineages. Why not 4 or 3? Just because I'm lazy enough. You can if you wish consider those as "tiny stars" or whatever but I'm not bothering listing them here.
Hence my small stars have between 5 and 9 basal branches. I have found a good deal mtDNA structures of this kind and will list them with a geographic logic:
In Africa we find only four of these star-like structures, all small. They are L3 (7 branches, two of them being the Eurasian macro-haplogroups M and N) and its subclade L3e1 (Central and East Africa), L1b1a (West Africa mostly) and L2a1c'd'e'h'i'j'k (East Africa basically). All them but L3 have just 5 branches. The lack of many and large star-like structures suggests that the demic growth in Africa was pretty much continuous, without many sudden expansive episodes like those we can detect in Eurasia, surely as signal of colonization of new frontiers in most cases.
In South Asia there are just three small stars: M4''64 (7 branches) and its sublineage M30 (5). Also M5a (5 spikes). M4''64 and M30 were probably sequential "aftershocks" of the M explosion itself. M5 instead seems more recent in time to my eye.
In East Asia, Siberia and/or America I find 7 star-like structures, which are: A (7 branches), M7a1a (7), C1b (6), D1 (6), D4a1 (5), D4h3a (5) and Z1'2'3'4'7 (5). All but A are derived from macro-haplogroup M (subclades: M7, M8 and D). Also all seem related to the colonization of the Northern fringes of Asia and/or America itself (except M7a1a1 if you wish, that seems mostly related to Japan instead).
It gives the impression that, barring macro-haplogroup N as such node, there were no large sudden demic expansions in South East Asia but rather a scatter of colonizations by diverse groups, leaving the signatures of rapid demic expansion for when some of these groups finally faced the Far North or the American new frontier: D1, D4h3 and C1b are exclusive of Native Americans.
In West Eurasia (and in some cases also parts of Africa or America) there are a lot of small stars, exactly 18: J1c (8 branches), H3 (7) X2 (7), T2 (7) and its subclade T2b (6), HV (6) and its subclade V (9), U5b3 (6), U6a (6), M1a (5), H1b'f'g'k'q (5), H2a (5), I (5), W(5), U2'3'4'7'8'9 (5) and its distant sublineages K1a1 (9) and K2a (6), R0a2 (5).
One third of these starlike structures belong to haplogroup R0, being surely related to the impressive spread of haplogroup H. Almost as many (5) belong to its "sister" haplogroup U, which probably spread in parallel, in my opinion.
In Oceania we only see one starlike structure and corresponds to haplogroup P (7 branches).
4 comments:
"macro-haplogroup N, with 12 branches, can also be considered in this group, participating in the Great Eurasian Expansion, along with its 'sister' M and its 'daughter' R".
Why do you believe that is necessarily so? Surely the 'mother' could expand quite some time before the 'daughter'.
"In South Asia there are just three small stars: M4''64 (7 branches) and its sublineage M30 (5). Also M5a (5 spikes). M4''64 and M30 were probably sequential 'aftershocks' of the M explosion itself".
Suggesting a rather leisurely expansion, rather than a rapid one along coasts and rivers?
"It gives the impression that, barring macro-haplogroup N as such node"
Again. Why do you persist in ignoring it's own expansion?
"Surely the 'mother' could expand quite some time before the 'daughter'".
Surely, indeed. The Great Eurasian Expansion, if you follow the way I describe it, is not a single moment but a process that begins with the M star and seems to end by the time of the R scatter. I don't know how long it took but it was some time, indeed.
The GEE is what happened between the OoA migration and the regionalization of the Eurasian peoples. It is an important phase that has not been paid much attention as such, at least on light of what I've read but that seems crucial to understand the genetics and prehistory of Eurasia and its peripherical regions.
"Suggesting a rather leisurely expansion, rather than a rapid one along coasts and rivers?"
After the M node yes maybe. A single rapid expansion followed by:
1. Localized slower expansions of many clades.
2. Some broader ones, notably those in the M4''64 (and M30) branch, which is widespread, and the M5 expansion (not sure of the details right now). M4''64 can be compared with N (smaller but not much smaller in fact).
"Why do you persist in ignoring it's own expansion?"
I'm not ignoring it. :?
I even placed it with the medium sized stars even if it's intermediate between them and the small ones.
What happens with N is that, excepting N9 and S (neither one forming a star), the daughter lineages take their time to spread in the East. Only R, in a different geographical context, would really make a serious impact.
So what happened with N is that it had an initial multi-branching episode, with many lineages heading in various directions. Of these only four are notable early on: N1'5, N9, S (none too impressive in their secondary expansion: no stars) and R (this one is the really impressive stuff within N).
"is not a single moment but a process that begins with the M star and seems to end by the time of the R scatter".
But then you go on to claim:
"macro-haplogroup N, with 12 branches, can also be considered in this group, participating in the Great Eurasian Expansion, along with its 'sister' M and its 'daughter' R".
Are you sure it was 'along with its sister M and its daughter R'? That sounds as though you do believe they all moved together. From the same place. That's why I often accuse you of believing in a 'Garden of Eden'. Surely all of M's daughter lines didn't move along with M. Nor did all of R's daughter lines mave along with R. So why must N's daughter R have moved along with N?
"So what happened with N is that it had an initial multi-branching episode, with many lineages heading in various directions".
And where did they finish up? Surely none need have been anywhere near R, where-ever R was. Secondary expansions are irelevant, except in so far as they suggest the different members of the star moved very little once they arrived somewhere near where they're found today.
What sounds to you is not necessarily what I meant or what sounds (hopefully) to the average reader.
I'm just describing the historical role of those macro-lineages in few words.
I'm sure you'd be happier if I wrote something like "participating in the Great Eurasian Expansion... from a undoubted Wallacean homeland, where they domesticated the cuscus, what explains the Moroccan dish of the same name, as well as the canoes of Pygmies and Groucho Marx (somehow)".
But it's not my way.
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