New DNA Papers

General discussions regarding DNA and its uses in genealogy research

Posts: 1730
Joined: Fri Mar 16, 2012 5:43 pm
PostPosted: Tue Mar 07, 2017 12:52 am
https://rd.springer.com/article/10.1007 ... 017-1769-8

Abstract
"The great apes (orangutans, gorillas, chimpanzees, bonobos and humans) descended from a common ancestor around 13 million years ago, and since then their sex chromosomes have followed very different evolutionary paths. While great-ape X chromosomes are highly conserved, their Y chromosomes, reflecting the general lability and degeneration of this male-specific part of the genome since its early mammalian origin, have evolved rapidly both between and within species. Understanding great-ape Y chromosome structure, gene content and diversity would provide a valuable evolutionary context for the human Y, and would also illuminate sex-biased behaviours, and the effects of the evolutionary pressures exerted by different mating strategies on this male-specific part of the genome. High-quality Y-chromosome sequences are available for human and chimpanzee (and low-quality for gorilla). The chromosomes differ in size, sequence organisation and content, and while retaining a relatively stable set of ancestral single-copy genes, show considerable variation in content and copy number of ampliconic multi-copy genes. Studies of Y-chromosome diversity in other great apes are relatively undeveloped compared to those in humans, but have nevertheless provided insights into speciation, dispersal, and mating patterns. Future studies, including data from larger sample sizes of wild-born and geographically well-defined individuals, and full Y-chromosome sequences from bonobos, gorillas and orangutans, promise to further our understanding of population histories, male-biased behaviours, mutation processes, and the functions of Y-chromosomal genes."

Posts: 1730
Joined: Fri Mar 16, 2012 5:43 pm
PostPosted: Tue Mar 07, 2017 8:50 am
dartraighe wrote:https://rd.springer.com/article/10.1007%2Fs00439-017-1769-8

Abstract
"The great apes (orangutans, gorillas, chimpanzees, bonobos and humans) descended from a common ancestor around 13 million years ago, and since then their sex chromosomes have followed very different evolutionary paths. While great-ape X chromosomes are highly conserved, their Y chromosomes, reflecting the general lability and degeneration of this male-specific part of the genome since its early mammalian origin, have evolved rapidly both between and within species. Understanding great-ape Y chromosome structure, gene content and diversity would provide a valuable evolutionary context for the human Y, and would also illuminate sex-biased behaviours, and the effects of the evolutionary pressures exerted by different mating strategies on this male-specific part of the genome. High-quality Y-chromosome sequences are available for human and chimpanzee (and low-quality for gorilla). The chromosomes differ in size, sequence organisation and content, and while retaining a relatively stable set of ancestral single-copy genes, show considerable variation in content and copy number of ampliconic multi-copy genes. Studies of Y-chromosome diversity in other great apes are relatively undeveloped compared to those in humans, but have nevertheless provided insights into speciation, dispersal, and mating patterns. Future studies, including data from larger sample sizes of wild-born and geographically well-defined individuals, and full Y-chromosome sequences from bonobos, gorillas and orangutans, promise to further our understanding of population histories, male-biased behaviours, mutation processes, and the functions of Y-chromosomal genes."



The estimated ancestor of all modern humans originated 350,000 ybp , so the above does not make one ounce of sense. The replication process today is 99% accurate. In the past the accuracy must have been greater, so it is not possible that humans and apes had the same ancestor if the replication process is near perfect. The more births the more mutations is what the scientists tell us. Will the chimps rule the world in 350,000 years and humans will become extinct, I asked the question already. The reply I got was that we are in the final phase of evolution. For those who believe in evolution there is no such state as the final phase. Evolution is either in a perpetual state or it isn't.

The 1% difference in our dna is mostly due to regional variation. That is what the scientists state.

Posts: 1730
Joined: Fri Mar 16, 2012 5:43 pm
PostPosted: Tue Mar 14, 2017 10:16 am
https://link.springer.com/article/10.10 ... 017-1770-2

Abstract
"Y-chromosomal variation in West Asian populations has so far been studied in less detail than in the neighboring Europe. Here, we analyzed 598 Y-chromosomes from two West Asian subregions—Transcaucasia and the Armenian plateau—using 40 Y-SNPs and 17 Y-STRs and combined them with previously published data from the region. The West Asian populations fell into two clusters: upland populations from the Anatolian, Armenian and Iranian plateaus, and lowland populations from the Levant, Mesopotamia and the Arabian Peninsula. This geographic subdivision corresponds with the linguistic difference between Indo-European and Turkic speakers, on the one hand, and Semitic speakers, on the other. This subdivision could be traced back to the Neolithic epoch, when upland populations from the Anatolian and Iranian plateaus carried similar haplogroup spectra but did not overlap with lowland populations from the Levant. We also found that the initial gene pool of the Armenian motherland population has been well preserved in most groups of the Armenian Diaspora. In view of the contribution of West Asians to the autosomal gene pool of the steppe Yamnaya archaeological culture, we sequenced a large portion of the Y-chromosome in haplogroup R1b samples from present-day East European steppe populations. The ancient Yamnaya samples are located on the “eastern” R-GG400 branch of haplogroup R1b-L23, showing that the paternal descendants of the Yamnaya still live in the Pontic steppe and that the ancient Yamnaya population was not an important source of paternal lineages in present-day West Europeans."

Posts: 1730
Joined: Fri Mar 16, 2012 5:43 pm
PostPosted: Wed Mar 15, 2017 1:32 pm
dartraighe wrote:More of the same old mantra. 40-50% of the males in western Europe today are descended from one man who lived 5000 years ago in western Europe. That is the reason that this paper is rubbish if they are referring to R1b.



"Thousands of horsemen may have swept into Bronze Age Europe, transforming the local population"

http://www.sciencemag.org/news/2017/02/ ... population

"The finding that Yamnaya men migrated for many generations also suggests that all was not right back home in the steppe. “It would imply a continuing strongly negative push factor within the steppes, such as chronic epidemics or diseases,” says archaeologist David Anthony of Hartwick College in Oneonta, New York, who was not an author of the new study. Or, he says it could be the beginning of cultures that sent out bands of men to establish new politically aligned colonies in distant lands, as in later groups of Romans or Vikings."

Why did the epidemics not push the women out of the Steppe????????????????? Were they immune to epidemics and diseases????????????????

The Romans and the Vikings had very little genetic impact on the regions they invaded!!!!!!!!!!!!!!



http://www.biorxiv.org/content/early/2017/03/14/114124

Abstract
"We fail to replicate a genetic signal for sex bias in the steppe migration to central Europe after ~5,000 years proposed by Goldberg et al. PNAS 114(10):2657-2662. Estimation of X-chromosome steppe ancestry in the Bronze Age central European population with the qpAdm method (Haak et al. Nature 522, 207-11) does not indicate lower steppe ancestry on the X-chromosome than in the autosomes. We perform a simulation which indicates presence of estimation bias of -19.5% in the inference of X-chromosome admixture proportions using the method used by Goldberg et al., largely eliminating the observed sex bias."

Posts: 1730
Joined: Fri Mar 16, 2012 5:43 pm
PostPosted: Wed Mar 22, 2017 3:09 pm
Reconciling evidence from ancient and contemporary genomes: a major source for the European Neolithic within Mediterranean Europe
Joana B. Pereira, Marta D. Costa, Daniel Vieira, Maria Pala, Lisa Bamford, Nourdin Harich, Lotfi Cherni, Farida Alshamali, Jiři Hatina, Sergey Rychkov, Gheorghe Stefanescu, Turi King, Antonio Torroni, Pedro Soares, Luísa Pereira, Martin B. Richards
Abstract

"Important gaps remain in our understanding of the spread of farming into Europe, due partly to apparent contradictions between studies of contemporary genetic variation and ancient DNA. It seems clear that farming was introduced into central, northern, and eastern Europe from the south by pioneer colonization. It is often argued that these dispersals originated in the Near East, where the potential source genetic pool resembles that of the early European farmers, but clear ancient DNA evidence from Mediterranean Europe is lacking, and there are suggestions that Mediterranean Europe may have resembled the Near East more than the rest of Europe in the Mesolithic. Here, we test this proposal by dating mitogenome founder lineages from the Near East in different regions of Europe. We find that whereas the lineages date mainly to the Neolithic in central Europe and Iberia, they largely date to the Late Glacial period in central/eastern Mediterranean Europe. This supports a scenario in which the genetic pool of Mediterranean Europe was partly a result of Late Glacial expansions from a Near Eastern refuge, and that this formed an important source pool for subsequent Neolithic expansions into the rest of Europe."
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