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Sunday, May 22, 2016

Parallel migrations in brown bears and humans within Eurasia


If, as per the abstract below, a major part of the Native American gene pool derives from the Altai-Sayan refugium, then it's likely to be the Ancient North Eurasian (ANE) part, rather than the East Asian part. So I'd say that for now the Altai-Sayan region looks like a pretty good option for the homeland of the ANE people (aka Mal'ta cluster).

Climatic changes during the Late Pleistocene had major impacts on the populations of many plant and animal species. During this period, humans and large mammals, e.g. brown bear and moose, were subject to analogous phylogeographic pressures and were linked by important ecological processes. However, evidence of human dispersal in northern Eurasia during the Late Pleistocene is scarce. Analysis of large mammals therefore has the potential to shed light on the population processes of humans during this period. We address several unresolved issues regarding the Late Pleistocene demography of brown bears: (a) the putative locations of refugia; (b) the direction of migrations across Eurasia and into North America; and (c) parallels with other mammals, including humans. We present results based on more than 200 complete mitochondrial genome sequences from Eurasian and North-American brown bears. Bayesian phylogenetic analysis revealed that most individuals belong to a very large Holarctic clade. The MRCA of this clade lived ca 40 thousand years ago, most likely in the Altai-Sayan area, a known Late Pleistocene refugium in Asia. We propose several migration scenarios for bears and suggest that brown bears and humans underwent a series of parallel migrations in Eurasia and to North America during the Late Pleistocene. Moreover, both species exhibited a demographic standstill in Beringia before colonizing North America. Synchrony in the timing of past migrations and standstill implies that the ecology of large mammals includes key limiting factors that can enhance our understanding of ancient human movements and on large carnivore conservation.

Saarma et al., Parallel migrations in brown bears and humans within Eurasia and into North America during the Late Pleistocene, ConGenomics 2016 abstract.

20 comments:

Krefter said...

Interesting stuff. I hope they have a system Brown bear mtDNA markers like human mtDNA. Something to keep in mind is Bears mature much younger than humans. So 40,000 years for them is about 200,000 years for humans. All human mtDNA/Y DNA comes from two lines when you go that far back.

Davidski said...

See here...

http://www.academia.edu/24317975/Sudden_expansion_of_a_single_brown_bear_maternal_lineage_across_northern_continental_Eurasia_after_the_last_ice_age_a_general_demographic_model_for_mammals

Grey said...

very cool - i like this kind of sideways approach

MH_82 said...

Sorry, not related to Polar Bears, but a very interesting article about Iberia :
https://www.academia.edu/23462994/Transition_and_conflict_at_the_end_of_the_3rd_millennium_BC_in_south_Iberia

It suggests if there was ever a suggestion of migration to southern Iberia after the Neolithic, but before proto-historic periods (eg Phoencians), then 2200 BC, with the advent of the El Agar culture might be it. Suggestive but not indisputable evidence for similarities between the finds in southern Iberia and some areas of Aegean.

? perhaps related to arrival of J2/ CHG people

Davidski said...

I'm betting that ancient DNA project on Iberian population history includes samples from El Agar, or it should anyway. But from memory it's scheduled to be completed in 2018, or something like that. So unless they put out some papers as they're going along, we might be waiting a long time.

MH_82 said...

A worthy wait ....

Davidski said...

Pain in the ass more like it.

Ideally, there should be an ancient genomes database online that is updated regularly as soon as new samples are sequenced.

But the problem is that no one's going to fund anything like that for the time being, because if they're going to spend, say, $200K on sequencing new samples, they'll want to first put out a paper and get some publicity out of it.

Davidski said...

By the way...

15 skeletons found at Harappan site in Hisar’s Rakhigarhi village

http://www.tribuneindia.com/news/haryana/15-skeletons-found-at-harappan-site-in-hisar-s-rakhigarhi-village/221923.html

The sources said excavators had opened 20 graves and skeletons had been found in 15 of them. They said DNA samples were being sent to the laboratories for bio-molecular scientific analysis.

The archeologists said the DNA samples would be analysed at the Centre for Cellular and Molecular Biology (CCMB), Hyderabad; Howard University, USA; and the Seoul National University, South Korea.


Do they mean Howard or Harvard? And if Howard, why?

Davidski said...

I think they screwed up in that article, but not that badly; what they probably mean is not Howard University, but Howard Hughes Medical Institute at Harvard.

Krefter said...

@Rob,
"? perhaps related to arrival of J2/ CHG people"

There's CHG in SouthWest Asia but I'm pretty sure it is small. The Near Eastern ancestry in Iberia, if it is there(which I think it is), had little CHG.

Nirjhar007 said...

Its a global collaboration , with no chances taken on the authenticity of the results.

MH_82 said...

@ Krefter

"There's CHG in SouthWest Asia but I'm pretty sure it is small. The Near Eastern ancestry in Iberia, if it is there(which I think it is), had little CHG."

I'm not sure if I understand your sentence, but there is some 20% CHG in Spaniards, no ?
That's not small, and I was not suggesting it came from 'SouthWest Asia"
And why would there be any doubts as to Near Eastern admixture in Iberia: it seems rather dominant, actually, if you combine EEF & CHG (70%) - even if some chunk of this ( ~ 10%) came with steppe admixture .

Cossue said...

Actually, accoding to http://eurogenes.blogspot.com.es/2016/03/d-statsnmonte-open-thread.html, Spaniards are mostly:

56% EEF (which itself is partly WHG, and partly basal)
20-30% Yamnaya (which itself is partly CHG)
10-12% extra WHG
2-6% extra CHG

Cossue said...

While, for example, Northern-Central French people would be:
47% EEF (partly WHG, partly basal)
36% Yamnaya (partly CHG)
11% extra WHG
3% extra CHG

And Southern French people:
55% EEF
22% Yamnaya
15% extra WHG
3.5% extra CHG

So, there's an interesting gradation there.

Krefter said...

@Rob,

Sorry I should have been more clear. By "Near Eastern" admixture I mean post-3000 BC ancestry from the Near East. Near Eastern ancestry our Neolithic and Bronze age European genomes lack. Near Eastern admixture from people similar to the ones living there today. Ones that have minor CHG ancestry.

There's no perfect way to accurately estimate CHG ancestry. 20% doesn't sound right. Anyways much of that would not be straight from the Near East but instead from Eastern Europe.

capra internetensis said...

Interesting abstract. IIRC moose colonized America at the same time as humans did as well.

I wonder if the 40 000 years means anything in particular? That would be around Greenland Stadial 9/Heinrich Event 4, which produced colder and stormier conditions (even by Ice Age standards) in Siberia as well as Europe. I don't know what effect this had on human occupation though. Seems too early to be the bottleneck leading to Y hg P1 but could have contributed to ANE-specific drift.

MH_82 said...

@ Krefter
@ Krefter


You need to go back and read my original statement, and properly digest that I was referring to a colonization from the Bronze Age Aegean or Anatolia, specifically to the said corner of southeast Iberia - El Agar. The paper I referenced clearly alludes to this, so whether you think it possible or not, is irrelevant, all the more given that you quite apparently know little if anything about the details of BA Iberia, or Europe in general.

If there was indeed a BA migration from the Aegean to Iberia, then it has nothing to do with modern 'middle Eastern people' - which appears to be what you're focussing on (as the latter don't come from Bronze Age Greece, last I checked).

Lastly, you claim 20% CHG in modern Spaniards doesn't 'sound right'.
Again, its not relevant what "sounds right' to you. In any case, just check the multiple data available from various threads here. Sure, some CHG came via central Europe & ultimately the steppe(as I clearly stated), but it appears a good chunk of it also came directly via Mediterranean routes.

Before attempting any grand-hypotheses (or retorting others'), you should make significant investment into coming to grips with basic geography & history, not to mention comprehension, writing & grammar.

Krefter said...

@Rob,

There's no need to be snippy. I don't understand why you're angry and gave a long response anyways.

"Before attempting any grand-hypotheses (or retorting others'), you should make significant investment into coming to grips with basic geography & history, not to mention comprehension, writing & grammar."

Congratulations you got an A+ in being a wannabe academic snob. Is that really who you want to be? Someone who trys to appear open minded and intellectual and who mocks people he thinks he's smarter than.

"If there was indeed a BA migration from the Aegean to Iberia, then it has nothing to do with modern 'middle Eastern people' - which appears to be what you're focussing on (as the latter don't come from Bronze Age Greece, last I checked). "

We need to forget about Asia/Europe borders when discussing genetics. Aegean is close to the Near East. People in SoutHEastern Europe today pull towards the Near East more than other Europeans. There's also a signal of Near Eastern admixture(not EEF or CHG) in Spain. I guess you could also call that a Aegean/Greek signal if you want. It does have to do with the Near East. There's no point in arguing about this it's fact.

Conclusion: Bronze age Greece and modern Middle East are connected. Admixture from either one would create a similar signal in Spain.

"The paper I referenced clearly alludes to this, so whether you think it possible or not, is irrelevant, all the more given that you quite apparently know little if anything about the details of BA Iberia, or Europe in general. "

I don't need to know about archaeology. All I need is DNA. I know from DNA there's Near Eastern admixture in Spain, that isn't EEF or CHG. There's hardly any CHG in Spain. If anything Lithuanians have more than Spanish.

D-stats dis agree with the idea of lots of CHG ancestry outside of the Caucasus mountains and SC Asia. The Agean or Near Eastern immigrants into Spain wouldn't have had lots of CHG.

MH_82 said...

Krefter

I'm not concerned about what definitions you wish to caste for the geography of the ancient world, as we all understand terms are relative. But Greece isn't in the Near East, unless one is completely clueless.

Like I said, if you wish to be understood better, you should work on your delivery. There is extra CHG in modern Spaniards over that which arrived from eastern Europe. If it wasn't there in the Neolithic, then the hypothesis that it came with some Bronze Age Mediterranean colonists, as posed by the paper, seems like a reasonable one to me.

And I wouldn't get too brash about your understanding of D-stats, either, as it seems you more often than not misunderstand things (NB the spelling: misunderstand, not "mis understand")

Karl_K said...

@Rob @Krefter

There's no need to be snippy or too brash. Mostly because these are words that almost nobody uses.

Seriously. If anyone wants to start an argument, please direct it at me. I love arguing, but I have never quite gotten the hang of starting arguments. Usually people just ignore me.