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Thread: Genetic Genealogy and Ancient DNA in the News

  1. #101
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    Direct estimates of natural selection in Iberia indicate calcium absorption was not the only driver of lactase persistence in Europe

    http://mbe.oxfordjournals.org/conten...a-d330d155046f

    Abstract:

    Lactase persistence (LP) is a genetically determined trait whereby the enzyme lactase is expressed throughout adult life. Lactase is necessary for the digestion of lactose – the main carbohydrate in milk – and its production is down-regulated after the weaning period in most humans and all other mammals studied. Several sources of evidence indicate that LP has evolved independently, in different parts of the world over the last 10,000 years, and has been subject to strong natural selection in dairying populations. In Europeans LP is strongly associated with, and probably caused by, a single C to T mutation 13,910bp upstream of the lactase (LCT) gene (-13,910*T). Despite a considerable body of research, the reasons why LP should provide such a strong selective advantage remains poorly understood. In this study we examine one of the most widely cited hypotheses for selection on LP – that fresh milk consumption supplements the poor vitamin D and calcium status of northern Europe's early farmers (the calcium assimilation hypothesis). We do this by testing for natural selection on -13,910*T using ancient DNA data from the skeletal remains of eight late Neolithic Iberian individuals, whom we would not expect to have poor vitamin D and calcium status because of relatively high incident UVB-light levels. None of the 8 samples successfully typed in the study had the derived T-allele. In addition, we reanalyse published data from French Neolithic remains to both test for population continuity and further examine the evolution of LP in the region. Using simulations that accommodate genetic drift, natural selection, uncertainty in calibrated radiocarbon dates, and sampling error, we find that natural selection is still required to explain the observed increase in allele frequency. We conclude that the calcium assimilation hypothesis is insufficient to explain the spread of lactase persistence in Europe.
    Paternal: R1b-U152 >> L2 >> FGC10543, Pietro della Rocca, b. 1559, Agira, Sicily, Italy
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  3. #102
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    Humanity's forgotten return to Africa revealed in DNA
    http://www.newscientist.com/article/...ed-in-dna.html

    Call it humanity's unexpected U-turn. One of the biggest events in the history of our species is the exodus out of Africa some 65,000 years ago, the start of Homo sapiens' long march across the world. Now a study of southern African genes shows that, unexpectedly, another migration took western Eurasian DNA back to the very southern tip of the continent 3000 years ago.

    According to conventional thinking, the Khoisan tribes of southern Africa, have lived in near-isolation from the rest of humanity for thousands of years. In fact, the study shows that some of their DNA matches most closely people from modern-day southern Europe, including Spain and Italy.

    Because Eurasian people also carry traces of Neanderthal DNA, the finding also shows – for the first time – that genetic material from our extinct cousin may be widespread in African populations....

    "These are very special, isolated populations, carrying what are probably the most ancient lineages in human populations today," says David Reich of Harvard University. "For a lot of our genetic studies we had treated them as groups that had split from all other present-day humans before they had split from each other."

    So he and his colleagues were not expecting to find signs of western Eurasian genes in 32 individuals belonging to a variety of Khoisan tribes. "I think we were shocked," says Reich.

    The unexpected snippets of DNA most resembled sequences from southern Europeans, including Sardinians, Italians and people from the Basque region (see "Back to Africa – but from where?"). Dating methods suggested they made their way into the Khoisan DNA sometime between 900 and 1800 years ago – well before known European contact with southern Africa (see map).

    Archaeological and linguistic studies of the region can make sense of the discovery. They suggest that a subset of the Khoisan, known as the Khoe-Kwadi speakers, arrived in southern Africa from east Africa around 2200 years ago. Khoe-Kwadi speakers were – and remain – pastoralists who make their living from herding cows and sheep. The suggestion is that they introduced herding to a region that was otherwise dominated by hunter-gatherers.
    Posted details of the actual paper here: http://www.anthrogenica.com/showthre...ll=1#post29931
    Last edited by Jean M; 02-03-2014 at 09:37 PM.

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  5. #103
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    http://www.nature.com/nature/journal...ture12921.html
    Although it is generally agreed that the Arctic flora is among the youngest and least diverse on Earth, the processes that shaped it are poorly understood. Here we present 50 thousand years (kyr) of Arctic vegetation history, derived from the first large-scale ancient DNA metabarcoding study of circumpolar plant diversity. For this interval we also explore nematode diversity as a proxy for modelling vegetation cover and soil quality, and diets of herbivorous megafaunal mammals, many of which became extinct around 10 kyr bp (before present). For much of the period investigated, Arctic vegetation consisted of dry steppe-tundra dominated by forbs (non-graminoid herbaceous vascular plants). During the Last Glacial Maximum (25–15 kyr bp), diversity declined markedly, although forbs remained dominant. Much changed after 10 kyr bp, with the appearance of moist tundra dominated by woody plants and graminoids. Our analyses indicate that both graminoids and forbs would have featured in megafaunal diets. As such, our findings question the predominance of a Late Quaternary graminoid-dominated Arctic mammoth steppe.

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  7. #104
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    I'm posting as a moderator. As requested I tried to move discussion of ancient Egyptians over to a thread where it can get its due amount of focus. http://www.anthrogenica.com/showthre...-and-their-DNA

    Hopefully, I picked out the right items to moved.

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  9. #105
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    Richard III's DNA to be analysed to create complete genome sequence
    http://www.theguardian.com/uk-news/2...e-sequence-dna

    The bones of the king under the car park have more to tell: scientists are to analyse the DNA from the remains of Richard III to create the world's first complete genome sequence for a named historical figure. The process could reveal his hair and eye colour, his susceptibility to conditions including Alzheimer's disease and diabetes, whether he was lactose intolerant, and whether the scoliosis that contorted his spine was genetic. It could also show if any of the surviving portraits, all completed years after his death, are accurate.

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  11. #106
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    The genome of a Late Pleistocene human from a Clovis burial site in western Montana, Morten Rasmussen, 2014: http://www.nature.com/nature/journal...ture13025.html
    Clovis, with its distinctive biface, blade and osseous technologies, is the oldest widespread archaeological complex defined in North America, dating from 11,100 to 10,700 14C years before present (bp) (13,000 to 12,600 calendar years bp)1, 2. Nearly 50 years of archaeological research point to the Clovis complex as having developed south of the North American ice sheets from an ancestral technology3. However, both the origins and the genetic legacy of the people who manufactured Clovis tools remain under debate. It is generally believed that these people ultimately derived from Asia and were directly related to contemporary Native Americans2. An alternative, Solutrean, hypothesis posits that the Clovis predecessors emigrated from southwestern Europe during the Last Glacial Maximum4. Here we report the genome sequence of a male infant (Anzick-1) recovered from the Anzick burial site in western Montana. The human bones date to 10,705 ± 35 14C years bp (approximately 12,707–12,556 calendar years bp) and were directly associated with Clovis tools. We sequenced the genome to an average depth of 14.4× and show that the gene flow from the Siberian Upper Palaeolithic Mal’ta population5 into Native American ancestors is also shared by the Anzick-1 individual and thus happened before 12,600 years bp. We also show that the Anzick-1 individual is more closely related to all indigenous American populations than to any other group. Our data are compatible with the hypothesis that Anzick-1 belonged to a population directly ancestral to many contemporary Native Americans. Finally, we find evidence of a deep divergence in Native American populations that predates the Anzick-1 individual.
    See also here: http://www.nature.com/news/ancient-g...debate-1.14698

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  13. #107
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    Y chromosomes of ancient Hunnu people and its implication on the phylogeny of East Asian linguistic families
    http://comonca.org.cn/lh/doc/A104.pdf
    we analyzed three samples of Hunnu ... determined Q-M3 ... Hunnu samples examined by multiple studies are belonging to the Q haplogroup. Q is mostly found in Yeniseian and American Indian peoples
    Yenisei

    Last edited by parasar; 02-13-2014 at 07:39 PM.

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  15. #108
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    Maja Krzewińska, Human origins and migrations in Norway inferred from ancient and modern DNA analysis (dissertation January 2014)

    http://www.mn.uio.no/ibv/forskning/a...scheme_phd.pdf

    A new Ph.D. project on human genetics, University of Oslo, shows that human Iron Age population of Norway was similar but not identical to extant Norwegians. Findings suggest that females were important agents in Viking expansions and that Viking Age society was stratified, diverse and multi-ethnic...

    The findings suggest that the Iron Age women were involved in Viking migration and colonisation processes, previously chiefly attributed to males. The results point to the importance of ancient DNA analyses in relation to human migration studies. The analyses of modern mitochondrial DNA and Y chromosome from 515 individuals from Bergen, Førde, Haugesund and Trondheim, revealed that geographically complex regions such as Norway, could harbour regionally structured human genetic variation, which could reflect both geographical isolation and historical events, such as Hanseatic trade and Iron Age migration.

    ...also shows that Iron Age and present day inhabitants of Norway were closely related but not identical as exposed by identification of extinct lineages and lineages characteristic of other than Norse ethnic groups. In addition, through collaboration with Elise Naumann and combination of different methods, namely
    ancient DNA and isotope analyses, the study revealed multiple burials from Norway Viking Age could house representatives of different social strata suggestive of slaves being buried with their masters.

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  17. #109
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    Quote Originally Posted by parasar View Post
    Y chromosomes of ancient Hunnu people and its implication on the phylogeny of East Asian linguistic families
    http://comonca.org.cn/lh/doc/A104.pdf


    Yenisei

    This blows my mind! To think that my wife's grandfather (Y-DNA Q-M3), whose father came from the Sierra Madre Oriental Mountains in Northern Mexico ultimately has roots in the Yenisei River Valley of Siberia. Crazy!

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  19. #110
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    That Norway study fits with what I have seen with mtDNA K1a10a. Google Map http://goo.gl/maps/u3wmC

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