What DNA Says About Aryan Invasion Theory -2

[Husky]

Not about AIT.



Post 1/2



www.newscientist.com/article/mg22129542.600-neanderthalhuman-sex-bred-light-skins-and-infertility.html

via rajeev2004.blogspot.co.uk/2014/01/whites-are-descended-from-neanderthals.html





(Wasn't it already long hypothesised that neanderthals may have interbred with homo sapiens? Is it that now's the first time they have genetic evidence?)





IMO the article's interesting not for the conclusions that Rajeev initially drew from it (especially since the subsequent article that he found stated that all non-Africans are thought to genetically be between 1%-3% Neanderthal - though only European and E Asian genomes were mentioned as having been considered in the study - and that the E Asians in the study had on avg more Neanderthal DNA than Europeans), but for the red bit below.

Neanderthal-human sex bred light skins and infertility

29 January 2014 by Michael Marshall

Magazine issue 2954. Subscribe and save



For similar stories, visit the Neanderthals , Genetics and Human Evolution Topic Guides



IT IS surprising what a little hanky-panky can do. A handful of sexual encounters between humans and Neanderthals made many of us what we are today, affecting both our appearance and our vulnerability to disease. But the genetic legacy left by the Neanderthals also highlights just how different we are from our sister species.



Neanderthals lived in Europe and Asia between about 200,000 and 30,000 years ago. Our species – sometimes dubbed "modern humans" – made it to Eurasia about 65,000 years ago, and so the two species had plenty of time to cosy up. In 2010, geneticists discovered that they had been very close neighbours indeed. They sequenced a Neanderthal genome and discovered it carried genes that also appear in the genomes of people of European and Asian descent: our species must have interbred with Neanderthals.



Now, by studying Neanderthal genes in people alive today, researchers are beginning to appreciate how that interbreeding influenced our species.



In one new study of 1000 human genomes, Sriram Sankararaman and David Reich of Harvard Medical School and colleagues found that Neanderthal DNA is most common in regions of the genome with the greatest genetic variability, making them a prime target for natural selection. While Neanderthal DNA may make up only 1.6 to 1.8 per cent of the Eurasian genome, it punches above its weight in terms of biological impact, says Reich (Nature, DOI: 10.1038/nature12961).



Joshua Akey and Ben Vernot of the University of Washington in Seattle have analysed the Neanderthal DNA in a further 665 humans (Science, DOI: 10.1126/science.1245938). Both their study and the Harvard one found a hotspot of Neanderthal ancestry in genes relating to keratin, a fibrous protein found in our hair, skin and nails.



One of the genes, BNC2, is involved in skin pigmentation. That implies that Eurasians owe their paler skins partly to Neanderthals. Light skin is an advantage at higher latitudes because it is more efficient at generating vitamin D from sunlight, so Neanderthal DNA may have helped modern humans to adapt to life outside Africa.



If so, the adaptation took thousands of years to become universal. A third study published this week describes a DNA analysis of one person who lived in Stone Age Europe about 7000 years ago – 40,000 years after any Neanderthal interbreeding. His genes suggest his skin was dark (Nature, doi.org/q74). It may be that the Neanderthal keratin affected early Eurasians' hair instead, perhaps straightening it.





Not all of the Neanderthal genes are beneficial. Sankararaman and Reich found that our Neanderthal inheritance includes several genes that make us susceptible to diseases including type 2 diabetes, lupus and Crohn's disease.



Some of the genes, meanwhile, appear to have led to fertility problems. For instance, Sankararaman found that the X chromosome is almost devoid of Neanderthal DNA. This suggests that most Neanderthal DNA that wound up on the X chromosome made the bearer less fertile – a common occurrence when related but distinct species interbreed – and so it quickly disappeared from the human gene pool. "Neanderthal alleles were swept away," says Sankararaman.



"This underlines that modern humans and Neanderthals are indeed different species," says Fred Spoor of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, who was not involved in any of the studies.



The genetic evidence further backs this up. Neanderthal DNA is irregularly spaced through the modern human genome rather than being fully mixed. That implies that interbreeding occurred very rarely. Sankararaman estimates it may have happened just four times.



"But these relatively few matings obviously were an important event in the history of non-Africans," says Reich.



This article appeared in print under the headline "Neanderthal sex, the aftermath"

economist.com/news/science-and-technology/21595403-genetic-contribution-neanderthal-man-made-modern-humanity

via rajeev2004.blogspot.co.uk/2014/02/more-on-interspecies-hanky-panky-of-out.html

Human evolution

Kissing cousins

[color="#0000FF"]The genetic contribution Neanderthal man made to modern humanity is clearer[/color]

Feb 1st 2014 | From the print edition



HOW Neanderthal are you? That question sounds vaguely insulting. But unless you are African, or of recent African ancestry, the answer is likely to be 1-3%.



Though Homo sapiens is the only type of human around at the moment, that was not true until recently. Sixty thousand years ago, when modern humans first left Africa, they encountered other species of humanity, such as Neanderthals (imagined above, in an artist’s interpretation), in Europe and Asia. In some cases, they interbred with them. The genetic traces of those encounters remain in modern human genomes. And two studies, one just published in Nature, and one in Science, have now looked in detail at this miscegenation, and tried to understand its consequences.





The Nature study, conducted by Sriram Sankararaman of Harvard Medical School and his colleagues, looked at the genomes of 1,004 living people of European and Asian descent and compared them with Neanderthal DNA from a 50,000-year-old toe bone found in a Siberian cave, and also with the genomes of 176 west Africans. This latter group, Dr Sankararaman assumed, could have little Neanderthal DNA in them because Neanderthals, as far as can be determined from the fossil record, lived only in Europe and western Asia.



Dr Sankararaman and his colleagues certainly did find plenty of DNA which seems to have come from Neanderthals in their Eurasians. Tellingly, it was not sprinkled evenly throughout the modern human genome. That let them make educated guesses about the effects it is having on those who carry it. For instance, genes affecting the production of keratin—an important component of hair and skin—showed more Neanderthal influence than most. Neanderthals, whose homeland was much colder then than it is now because of the ice age, were hairier (and thus better insulated) than Homo sapiens. Retaining Neanderthal traits of this sort, in an African species that was trying to make good in sub-Arctic conditions, would thus be encouraged by natural selection.



More surprisingly, Dr Sankararaman also found Neanderthal DNA in genes associated with diabetes, Crohn’s disease, lupus and even the propensity to smoke. This does not necessarily mean such DNA was bad for those who inherited it. A gene which increases the risk of diabetes in modern circumstances of abundant food might, for example, have had benefits in a more austere environment.



Indeed, truly deleterious DNA would be expected to be noticeable by its absence, because natural selection would have worked to eliminate it in the 30,000 years since Neanderthals died out. And Dr Sankararaman found evidence for exactly that, as well.

(So any Neanderthal interbreeding with homo sapiens who had moved out of Africa would have had to take place 30,000 years ago at latest?)



There is, for example, little Neanderthal DNA on the X chromosome (which, along with the Y chromosome, determines an individual’s sex). Nor is there much in genes that are expressed in the testicles. Studies from other hybrid animals, which are frequently sterile, suggest genes which reduce male fertility are often found on the X chromosome. Since few things are a bigger evolutionary no-no than being unable to produce children, tremendous selective pressure would have existed to remove the offending DNA from the hybrid descendants of Neanderthals and Homo sapiens.



The study published in Science, by Benjamin Vernot and Joshua Akey of the University of Washington, in Seattle, reaches similar conclusions to Dr Sankararaman’s. Dr Vernot and Dr Akey hunted down Neanderthal DNA in the genomes of 665 Europeans and East Asians. They, too, found evidence of its having inserted itself into genes associated with the skin, and that not all of the newly arrived genetic material is helpful to its current bearers.



They made other discoveries, too. With the help of computer models, they concluded that there were probably several pulses of interbreeding over the millennia, rather than a steady stream of it. Both they and Dr Sankararaman also found that, on average, East Asians have more Neanderthal DNA than Europeans do—which is odd, because Neanderthals are not known to have lived in East Asia.



The ghost in the machine



Dr Vernot and Dr Akey also used their data to try to improve understanding of the Neanderthal genome itself, by combining the bits and bobs scattered among modern humans. Though both their study and Dr Sankararaman’s depended on being able to identify what was Neanderthal by comparing modern human genomes with fossil DNA, the fossil material available is imperfect. Looking at the exact sequence of DNA “letters” (the chemical bases which carry the genetic message) in areas identified as Neanderthal in modern genomes can therefore improve understanding of the Neanderthal original.



Crucially, though the amount of Neanderthal DNA in any individual is small, the exact bits vary a lot from person to person. Look at enough people, then, and it becomes possible to rebuild quite large swathes of the Neanderthal genome. Dr Vernot and Dr Akey reckon that from their sample of 665 they have recovered around 20% of it.



This is an impressive figure for an extinct species. It shows just how much the concept of a “species” is a construct of human thinking rather than a truly natural category. Technically, Neanderthals may be gone. But their DNA ghosts linger on.



From the print edition: Science and technology

Before continuing, first the aside. Concerning these 2 statements in the 2nd article:

1. "The study published in Science, by Benjamin Vernot and Joshua Akey of the University of Washington, in Seattle, reaches similar conclusions to Dr Sankararaman’s. Dr Vernot and Dr Akey hunted down Neanderthal DNA in the genomes of 665 Europeans and East Asians. They, too, found evidence of its having inserted itself into genes associated with the skin, and that not all of the newly arrived genetic material is helpful to its current bearers."



2. "They made other discoveries, too. With the help of computer models, they concluded that there were probably several pulses of interbreeding over the millennia, rather than a steady stream of it. Both they and Dr Sankararaman also found that, on average, East Asians have more Neanderthal DNA than Europeans do—which is odd, because Neanderthals are not known to have lived in East Asia."



(The fact that they find this odd - does it mean they know for certain that ancestors of E Asian populations could not have had Neanderthal input before they moved into E Asian regions? Alternatively, maybe a cluster of Neanderthals did live in their vicinity but no evidence of Neanderthals' historical presence has yet been found in the fossil record there?

Why is my suspicious mind thinking they will namedrop the Ainu of Japan or the Kennewick Man of North America next?

And there's another suspicion. It's probably an irrational fear.)

Anyway. The opening statement that all non-Africans tend to have 1% to 3% Neanderthal DNA... yet most of the article only speaks of Europeans and E Asians. What is the % in native Australians or native Americans or other Asian (incl. Indians) or Middle East? Were these even studied? But surely they must have been, else why generalise for "all non-Africans"?





Moving on. Want to draw attention again to the 3 studies mentioned in the first link, in order to discuss the red bit - which I think is rather interesting:

1. "In one new study of 1000 human genomes, Sriram Sankararaman and David Reich of Harvard Medical School and colleagues found that Neanderthal DNA is most common in regions of the genome with the greatest genetic variability, making them a prime target for natural selection. While Neanderthal DNA may make up only 1.6 to 1.8 per cent of the Eurasian genome, it punches above its weight in terms of biological impact, says Reich (Nature, DOI: 10.1038/nature12961)."



2. "Joshua Akey and Ben Vernot of the University of Washington in Seattle have analysed the Neanderthal DNA in a further 665 humans (Science, DOI: 10.1126/science.1245938). Both their study and the Harvard one found a hotspot of Neanderthal ancestry in genes relating to keratin, a fibrous protein found in our hair, skin and nails."



3. "A third study published this week describes a DNA analysis of one person who lived in Stone Age Europe about 7000 years ago – 40,000 years after any Neanderthal interbreeding. His genes suggest his skin was dark (Nature, doi.org/q74). It may be that the Neanderthal keratin affected early Eurasians' hair instead, perhaps straightening it."

Notice how the first 2 studies specifically went looking for and noticed Neanderthal DNA. The *third* study does not mention anything about neanderthal DNA (and was not looking for it) as per what's in the news article. All the text says about the 3rd study is that the DNA analysis of one person who lived in Stone Age Europe about 7000 years ago had genes that suggest his skin was dark. It is *NewScientist* that has decided to tie the discoveries in studies 1 and 2 about Neanderthals, into what study 3 says, and where/how Neanderthal genetics may fit into the picture that study 3 reveals.



Study 3's actual discovery in itself - which said nothing about Neanderthals though - is what's really interesting: they found a native of Europe 7000 years ago that likely had dark skin. And 7000 years is not at all long ago:



E.g. "Kurgan culture" in Southern Russia according to Elst in his Sati article was "definitely IE":

From archaeological excavations in Southern Russia it appears that widows were already climbing the funeral pyres of their deceased husbands in the fourth millennium before our chronology, in the so-called Kurgan-culture, an apparantly proto-Scythian and definitely Indo-European culture.

While cases of "Sati" like practices among them occurred in the 4th millennium BCE, Kurgan kultur's origins are itself dated to 5th millennium BCE. Which is between 6000 and 7000 years ago.



en.wikipedia.org/wiki/Kurgan

Those scholars who follow Gimbutas identify a "Kurgan culture" as reflecting an early Indo-European ethnicity which existed in the steppes and southeastern Europe from the 5th to 3rd millennia BC.

Anyway. Confirmed: no Neanderthal stuff mentioned in the paper on the dark-skinned European -



nature.com/nature/journal/vaop/ncurrent/full/nature12960.html

(doi.org/q74)

Derived immune and ancestral pigmentation alleles in a 7,000-year-old Mesolithic European



Iñigo Olalde,1, 18 Morten E. Allentoft,2, 18 Federico Sánchez-Quinto,1 Gabriel Santpere,1 Charleston W. K. Chiang,3 Michael DeGiorgio,4, 5 Javier Prado-Martinez,1 Juan Antonio Rodríguez,1 Simon Rasmussen,6 Javier Quilez,1 Oscar Ramírez,1 Urko M. Marigorta,1 Marcos Fernández-Callejo,1 María Encina Prada,7 Julio Manuel Vidal Encinas,8 Rasmus Nielsen,9 Mihai G. Netea,10 John Novembre,11 Richard A. Sturm,12 Pardis Sabeti,13, 14 Tomàs Marquès-Bonet,1, 15 Arcadi Navarro,1, 15, 16, 17 Eske Willerslev2 & Carles Lalueza-Fox



Ancient genomic sequences have started to reveal the origin and the demographic impact of farmers from the Neolithic period spreading into Europe1, 2, 3. The adoption of farming, stock breeding and sedentary societies during the Neolithic may have resulted in adaptive changes in genes associated with immunity and diet4. However, the limited data available from earlier hunter-gatherers preclude an understanding of the selective processes associated with this crucial transition to agriculture in recent human evolution. Here we sequence an approximately 7,000-year-old Mesolithic skeleton discovered at the La Braña-Arintero site in León, Spain], to retrieve a complete pre-agricultural European human genome. Analysis of this genome in the context of other ancient samples suggests the existence of a common ancient genomic signature across western and central Eurasia from the Upper Paleolithic to the Mesolithic. The La Braña individual carries ancestral alleles in several skin pigmentation genes, suggesting that the light skin of modern Europeans was not yet ubiquitous in Mesolithic times. Moreover, we provide evidence that a significant number of derived, putatively adaptive variants associated with pathogen resistance in modern Europeans were already present in this hunter-gatherer.

Grief, every interesting journal article requires membership/pay access. Why can't this information be free for all to read?





[color="#0000FF"]Question: What bearing does the time-frame have on the common white-supremacist version of PIE-ism: that Proto-Indo-Europeans were "white". (Or that Europe is "white" even originally. Etc.*)

Am I right in thinking that such data actually indicates both an upper limit (and at least one lower limit - to be found in the IE Kurgans) on an all-white PIE population in the urheimat scenario?[/color]

I mean, there's not much time for dark European (from 7000 years ago) to turn all-white in time for - as white supremacists claim - an all-white PIE or IE=post-PIE Kurgan kultur (from between 7000 and 6000 years ago). And their darkness / the frequency of dark Europeans is only going to be greater *before* that - which says something about any PIE that is set earlier - so...



[* NewScientist choosing to tie the Neanderthal studies into the "Dark-skinned European" study - with the "maybe they started Europeanising by getting straight hair at this period"* - seems almost to imply a subconcious need to clearly delineate in some other way between Europeans and Africans. Perhaps since 7000 years ago is rather all too recent?]

His genes suggest his skin was dark (Nature, doi.org/q74). It may be that the Neanderthal keratin affected early Eurasians' hair instead, perhaps straightening it.