Brit-Am Anthropology and DNA Update
Contents:
1. Why Amish live longer
2. Netherlands.
Does natural selection favour taller stature among the tallest people on earth?
3. Scientists track last 2,000 years of British evolution
4. Sweeping DNA Survey Highlights Vikings' Surprising Genetic Diversity
5. Notes on R1b and J2 in Europe
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1. Why Amish live longer
https://en.wikipedia.org/wiki/Recent_human_evolution
A 2017 study by researchers from Northwestern University unveiled a mutation among the Old Order Amish living in Berne, Indiana, that suppressed their chances of having diabetes and extends their life expectancy by about ten years on average. That mutation occurred in the gene called Serpine1, which codes for the production of the protein PAI-1 (plasminogen activator inhibitor), which regulates blood clotting and plays a role in the aging process. About 24% of the people sampled carried this mutation and had a life expectancy of 85, higher than the community average of 75. Researchers also found the telomeres' non-functional ends of human chromosomes of those with the mutation to be longer than those without. Because telomeres shorten as the person ages, they determine the person's life expectancy. Those with longer telomeres tend to live longer. At present, the Amish live in 22 U.S. states plus the Canadian province of Ontario. They live simple lifestyles that date back centuries and generally insulate themselves from modern North American society. They are mostly indifferent towards modern medicine, but scientists do have a healthy relationship with the Amish community in Berne. Their detailed genealogical records make them ideal subjects for research.
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2. Netherlands.
Does natural selection favour taller stature among the tallest people on earth?
https://royalsocietypublishing.org/doi/full/10.1098/rspb.2015.0211
Gert Stulp, Louise Barrett, Felix C. Tropf and Melinda Mills
Abstract
The Dutch are the tallest people on earth. Over the last 200 years, they have grown 20 cm in height: a rapid rate of increase that points to environmental causes. This secular trend in height is echoed across all Western populations, but came to an end, or at least levelled off, much earlier than in The Netherlands. One possibility, then, is that natural selection acted congruently with these environmentally induced changes to further promote tall stature among the people of the lowlands. Using data from the LifeLines study, which follows a large sample of the population of the north of The Netherlands (n = 94 516), we examined how height was related to measures of reproductive success (as a proxy for fitness). Across three decades (1935-1967), height was consistently related to reproductive output (number of children born and number of surviving children), favouring taller men and average height women. This was despite a later age at first birth for taller individuals. Furthermore, even in this low-mortality population, taller women experienced higher child survival, which contributed positively to their increased reproductive success. Thus, natural selection in addition to good environmental conditions may help explain why the Dutch are so tall.
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3. Scientists track last 2,000 years of British evolution
Forwarded by Mark Williams
Technique tested on Britons' genomes provides first look at human genetic adaptation over the past 2,000 years.
https://www.nature.com/news/scientists-track-last-2-000-years-of-british-evolution-1.19917
Anna Nowogrodzki
Extract:
People of British origin are better able to digest milk than their ancestors were just two millennia ago.
Humans may be members of an advanced species, but we haven't stopped evolving. Over the past 2,000 years, British people have adapted to become taller and blonder, more likely to have blue eyes and better able to digest milk, according to researchers who have developed a technique to track very recent changes in the human genome.
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4. Sweeping DNA Survey Highlights Vikings' Surprising Genetic Diversity
https://www.smithsonianmag.com/smart-news/dna-analysis-reveals-vikings-surprising-genetic-diversity-180975865/
A new study suggests Viking identity didn't always equate to Scandinavian ancestry
By Tara Wu
SEPTEMBER 18, 2020
Extracts:
The term 'Viking' tends to conjure up images of fierce, blonde men who donned horned helmets and sailed the seas in longboats, earning a fearsome reputation through their violent conquests and plunder.
But a new study published in the journal Nature suggests the people known as Vikings didn't exactly fit these modern stereotypes. Instead, a survey deemed the 'world's largest-ever DNA sequencing of Viking skeletons' reinforces what historians and archaeologists have long speculated: that Vikings' expansion to lands outside of their native Scandinavia diversified their genetic backgrounds, creating a community not necessarily unified by shared DNA.
As Erin Blakemore reports for National Geographic, an international team of researchers drew on remains unearthed at more than 80 sites across northern Europe, Italy and Greenland to map the genomes of 442 humans buried between roughly 2400 B.C. and 1600 A.D.
The results showed that Viking identity didn't always equate to Scandinavian ancestry. Just before the Viking Age (around 750 to 1050 A.D.), for instance, people from Southern and Eastern Europe migrated to what is now Denmark, introducing DNA more commonly associated with the Anatolia region. In other words, writes Kiona N. Smith for Ars Technica, Viking-era residents of Denmark and Sweden shared more ancestry with ancient Anatolians than their immediate Scandinavian predecessors did.
Other individuals included in the study exhibited both Sami and European ancestry, according to the New York Times, James Gorman. Previously, researchers had thought the Sami, a group of reindeer herders with Asiatic roots, were hostile toward Scandinavians.
Overall, the scientists found that people who lived in Scandinavia exhibited high levels of non-Scandinavian ancestry, pointing to a continuous exchange of genetic information across the broader European continent.Scandinavians. (Public domain via Wikimedia Commons)
In addition to comparing samples collected at different archaeological sites, the team drew comparisons between historical humans and present-day Danish people. They found that Viking Age individuals had a higher frequency of genes linked to dark-colored hair, subverting the image of the typical light-haired Viking.
'It's pretty clear from the genetic analysis that Vikings are not a homogenous group of people,' lead author Eske Willerslev, director of the University of Copenhagen's Center of Excellence GeoGenetics, tells National Geographic. 'A lot of the Vikings are mixed individuals.'
He adds, 'We even see people buried in Scotland with Viking swords and equipment that are genetically not Scandinavian at all.'
Per the Times, the researchers report that Vikings genetically similar to modern Danes and Norwegians tended to head west on their travels, while those more closely linked to modern Swedes preferred to journey eastward. Still, exceptions to this pattern exist: As Ars Technica notes, Willerslev and his colleagues identified an individual with Danish ancestry in Russia and a group of unlucky Norwegians executed in England.
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5. Notes on R1b and J2 in Europe
Haplogroup R1b (DNA)
https://www.eupedia.com/europe/Haplogroup_R1b_Y-DNA.shtml
R1b is the most common haplogroup in Western Europe, reaching over 80% of the population in Ireland, the Scottish Highlands, western Wales, the Atlantic fringe of France, the Basque country and Catalonia. It is also common in Anatolia and around the Caucasus, in parts of Russia and in Central and South Asia. Besides the Atlantic and North Sea coast of Europe, hotspots include the Po valley in north-central Italy (over 70%), Armenia (35%), the Bashkirs of the Urals region of Russia (50%), Turkmenistan (over 35%), the Hazara people of Afghanistan (35%), the Uyghurs of North-West China (20%) and the Newars of Nepal (11%). R1b-V88, a subclade specific to sub-Saharan Africa, is found in 60 to 95% of men in northern Cameroon.
The three main branches of R1b1 (R1b1a, R1b1b, R1b1c) all seem to have stemmed from the Middle East.
It has been hypothetised that R1b people (perhaps alongside neighbouring J2 tribes) were the first to domesticate cattle in northern Mesopotamia some 10,500 years ago.
Nowadays small percentages (1 to 4%) of R1b-V88 are found in the Levant, among the Lebanese, the Druze, and the Jews, and almost in every country in Africa north of the equator. Higher frequency in Egypt (5%), among Berbers from the Egypt-Libya border (23%), among the Sudanese Copts (15%), the Hausa people of Sudan (40%), the the Fulani people of the Sahel (54% in Niger and Cameroon), and Chadic tribes of northern Nigeria and northern Cameroon (especially among the Kirdi), where it is observed at a frequency ranging from 30% to 95% of men.
It had first been hypothetised that R1b was native to Western Europe, because this is where it was most prevalent. It has since been proven that R1b haplotypes displayed higher microsatellite diversity in Anatolia and in the Caucasus than in Europe. European subclades are also more recent than Middle Eastern or Central Asian ones.
Haplogroup J2 (DNA)
https://www.eupedia.com/europe/Haplogroup_J2_Y-DNA.shtml
Haplogroup J2 is thought to have appeared somewhere in the Middle East towards the end of the last glaciation,
The Romans probably helped spread haplogroup J2 within their borders, judging from the distribution of J2 within Europe (frequency over 5%), which bears an uncanny resemblance to the borders of the Roman Empire (once concessions are made for the Germanic invasions that appear to have lowered the frequency of J2 between Belgium and Switzerland).