June 04, 2009

mtDNA haplogroup U5b3 (Pala et al. 2009)

As always, time estimates depend on the mutation rate used:
Because the mutation rate of Mishmar et al.37 is probably an overestimate, mainly caused by partial saturation of some synonymous mutations,40 and that of Kivisild et al.39 represents an underestimate,41 we used the intermediate global coalescence time of modern human mtDNA recently proposed by Perego et al.42 as a reference point for the internal calibration of both approaches. Accordingly, we converted the haplogroup sequence divergences into time estimates by using averaged time calibrations corresponding to 4610 years per coding-region substitution and 7650 years per synonymous transition (Table 1). With this approach, the coalescence time estimates for the entire U5b3 are between 10.1 ky and 8.1 ky.
See Time dependency of the human mtDNA evolutionary mutation rate for some discussion of mutation rates and archaeological correlations, and the newer paper on Purifying selection and the mtDNA clock.

American Journal of Human Genetics doi:10.1016/j.ajhg.2009.05.004

Mitochondrial Haplogroup U5b3: A Distant Echo of the Epipaleolithic in Italy and the Legacy of the Early Sardinians

Maria Pala et al.

Abstract

There are extensive data indicating that some glacial refuge zones of southern Europe (Franco-Cantabria, Balkans, and Ukraine) were major genetic sources for the human recolonization of the continent at the beginning of the Holocene. Intriguingly, there is no genetic evidence that the refuge area located in the Italian Peninsula contributed to this process. Here we show, through phylogeographic analyses of mitochondrial DNA (mtDNA) variation performed at the highest level of molecular resolution (52 entire mitochondrial genomes), that the most likely homeland for U5b3a haplogroup present at a very low frequency across Europewas the Italian Peninsula. In contrast to mtDNA haplogroups that expanded from other refugia, the Holocene expansion of haplogroup U5b3 toward the North was restricted by the Alps and occurred only along the Mediterranean coasts, mainly toward nearby Provence (southern France). From there, 7,0009,000 years ago, a subclade of this haplogroup moved to Sardinia, possibly as a result of the obsidian trade that linked the two regions, leaving a distinctive signature in the modern people of the island. This scenario strikingly matches the age, distribution, and postulated geographic source of a Sardinian Y chromosome haplogroup (I2a2-M26), a paradigmatic case in the European context of a founder event marking both female and male lineages.

Link

10 comments:

South Central Haplo said...

These data render an outof- Africa dispersal prior to the Toba eruption in Sumatra at ~74 kya less likely.

What about archeological proof of Human settlements before Toba eruption?.

Paper is good. why do they need to extend their arguments above archeological proof!!!!

Gioiello said...

Italy wasn't an important refuge? Who does say this? I not.
I think having demonstrated that the hgs. at a low frequence demonstrate a presence better than the massive one, which, being present overall, don't permite the location of their origin. See hg. R1b2b2 and the Franco-Cantabrian refugium! If my theory is right, I think we must expect to find this haplogroup at a very low frequence overall in Europe, perhaps in isolated region.

Maju said...

Italy wasn't an important refuge? Who does say this?.

Italy was populated by AMHs all the time since Aurignacian (north) and Gravettian (all but Sardinia). But Italy does not look an important source for other cultures in Europe after the LGM. While Western Magdalenian (and even to some extent Solutrean before it) expanded into Central and Northern Europe (derived Epipaleolithic cultures), Italy remained Epigravettian, ignoring Magdalenian altogether.

This implies that the Alps, then a huge mass of ice from Nice to Slovenia were a real barrier for culural and demic spread. Neither UP Italians colonized north or west of the Alps, nor westerners colonized Italy.

You can look at the archaeological before you even consider the gentic one. Makes things a lot easier (at least where archaeology is well developed as is the case of Europe).

Gioiello said...

But probably all your Westerners didn't survive the Younger Dryas,if the dominant YDNA (R1b1b2) went from East: someone thinks not more than 4000YBP (from Russia or from Middle East?), I think that he was here some thousands of years before. My theory is that he was that European hunter-gatherer who took agriculture from the Middle-Eastner farmers (G2a and J2), and certainly lived in Italy or nearby, not in Spain. Italy has also some rare mtDNA, not only U5b3a but also N1b, R0a etc., that I think can demonstrate from where Western Europeans of to-day came.
Not counting K, above all my K1a(1b1), that from Sykes to others is thought to have its origin in Italy and Otzi lived in Italy, not in Spain, where mtDNA K isn't present before very recent times.

Maju said...

There is no reasonable doubt on the case, Gioello: there is clear continuity through the Magdalenian into Epipaleolithic.

The debate rages only in regard to Neolithic and post-Neolithic events but, as I have said before many times, there is no possible post-Paleolithic event or process that can explain the current distribution of R1b in Europe.

My theory is that he was that European hunter-gatherer who took agriculture from the Middle-Eastner farmers (G2a and J2), and certainly lived in Italy or nearby, not in Spain. Italy has also some rare mtDNA, not only U5b3a but also N1b, R0a etc., that I think can demonstrate from where Western Europeans of to-day came.

Italy, notably southern and central Italy played a role in Cardium Pottery (which is not original from West Asia but from the Western Balcans anyhow). But CP is demonstrated archaeologically to have made only so many colonial foundations, being most of it aculturized natives (who continued with ancient tool-making traditions rooted locally). Whatever the case, CP is restricted to central and western Mediterranean areas (plus an offshot in Lebanon).

Overall European agriculture began in Northern Greece and, while it's probably rooted in West Asian one, it has a very marked unique personality and an almost totally autonomous evolution since pre-Sesklo. It had two expansion routes: one continental towards the Danub and then around it (Balcano-Danubian Neolithic) and another along the Mediterranean Sea (Cardial Neolithic). It's impossible to associate either or both processes to modern R1b distribution no matter how you look at it.

Others have argued that Indoeuropeans but again this seems to make no sense. The only cultural pattern that approximates very well the modern extension of R1b1b2a (i.e. the West European clade of R1b) are Magdalenian (or maybe its remote antecessor: Aurignacian, that had a similar distribution).

Not counting K, above all my K1a(1b1), that from Sykes to others is thought to have its origin in Italy and Otzi lived in Italy, not in Spain, where mtDNA K isn't present before very recent times.

In this you may be right. MtDNA K is mostly distibuted around the alps and it has not been detected in Epipaloelithic nor Neolithic samples in Portugal. It is also very rare among Basques (but it's sister U8a is typical Basque instead). I'd say that there is a strong possibility that U8 spread with Aurignacian and that K had a near-Italy coalescence maybe (could be Balcans too?)

Gioiello said...

Many thanks for your learned response, but for supporting your theory (re R1b1b2a: mine) you must break the positions of Vizachero and others. Anyway I am with you.

Gioiello said...

From "Genealogy-DNA":

Sorenson Molecular Genealogy
Foundation Assists International Scientific Team in Establishing Italian
Peninsula as a Significant Source of the People Who Recolonized Post-Ice Age
Europe ; * Italy Acted as a Refuge for Paleolithic Humans When Advancing Ice Sheets
and Permafrost of the Last Glacial Maximum Forced Abandonment of Most of
European Continent for 10,000 Years * Large Sample of Rare European
Mitochondrial DNA Analyzed at Highest Level of Molecular Resolution Provides
Evidence to Fill Gaps in Scientific Record * Research will be Published in the
June 12 Issue of American Journal of Human Genetics

Maju said...

This is not a military struggle, hence I need not to break the positions of anybody. Truth defends itself and is pretty stubborn.

I just discuss where I can because I normally find it enjoyable, not to win any war but to share information, to make a point, to exchange opinions and that's about it. The world won't be any better or any worst for that reason.

Sincerely, while these issues of prehistory and genetics are interesting and even fascinating, what really matters are things like child slavery, destruction of the sea or colonial racism in Palestine. There is where a war can and must be fought - and won.

Gioiello said...

If you recall why I was banned from two forums and by whom, you'll be able to understand that others make wars and always they have blown under the belt. You, as you speak, are an izquierdo. I not, and my wars I do make also by myself and, sincerely, I feel having already won it.

terryt said...

"while these issues of prehistory and genetics are interesting and even fascinating, what really matters are things like child slavery, destruction of the sea or colonial racism in Palestine".

Very true. However such issues are very often supported by mythological beliefs about the past. In that case exposing those beliefs to the truth will help bring about the changes in beliefs that really matter.