Brit-Am Anthropology and DNA Update (6 September 2015, 22 Elul 5775)
Contents:
1. Smoking Marijuana Lowers Fertility [in both men and women]
2. Study: Holocaust trauma can be genetically transmitted
3. English More Celtic than Anything Else
British Origins (Leslie et al. 2015)
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1. Smoking Marijuana Lowers Fertility [in both men and women]
http://www.webmd.com/men/news/20031013/smoking-marijuana-lowers-fertility
Sperm Burn Out, Less Potent When Men -- or Women -- Smoke Marijuana
By Daniel J. DeNoon
WebMD Health News
Extracts:
Oct. 13, 2003 -- Smoking marijuana makes sperm less fertile -- even if the woman is the one who smokes it, a new study shows.
The smokers weren't the only ones who got high. The drug affected their sperm, too. These stoned sperm party hard. And then? They burn out, researchers say.
"Marijuana-smoking men's sperm are hyper. They are way out there," Burkman tells WebMD. "They already have begun the vigorousswimming called hyperactivation. Sperm should be quiet at first. They should be waiting to be washed into cervix and approach the egg before they start hyperactivation."
Of course, men who smoke marijuana do get women pregnant. But some men are more fertile than others, or are more fertile at different times of their lives. Smoking marijuana, Burkman warns, will make a borderline-infertile man frankly infertile.
"The marijuana-smoking men had significantly lower semen volume," Burkman says. "Many had pretty low volume, about half the male norm. If they came to our clinic as patients, we'd tell them they are abnormal. ... They are delivering significantly fewer sperm to the female when they have sexual intercourse."
Burkman's team studied only men. But she says that when women smoke marijuana, the active ingredient -- THC -- appears in their reproductive organs and vaginal fluids. Sperm exposed to this THC are likely to act just as sperm exposed to THC in the testes.
"When women smoke marijuana, nicotine, or other drugs, their reproductive fluids contain these drugs," Burkman says. "The woman smoking marijuana is putting THC into her oviduct, into her cervix. If the man is not smoking but the woman is, his sperm go into her body and hit THC in the vagina, oviduct, and uterus. Her THC is changing his sperm."
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2. Study: Holocaust trauma can be genetically transmitted
http://www.ynetnews.com/articles/0,7340,L-4693259,00.html
Researchers at Mount Sinai hospital in New York find the same hormonal abnormalities in both Holocaust survivors and their children.
Extracts:
The research, which was published in the journal Biological Psychiatry, included 32 test subjects, Jewish men and women who were at concentration camps during the Holocaust, witnessed or experienced torture, or had to hide from the Nazis during World War II.
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Researchers said this is the first demonstration of how psychological trauma endured by a person can have intergenerational effects on his offspring.
Researchers also examined the genes of 22 of their adult offspring and compared them to Jewish families who did not live in Europe during the Nazis' rule.
Children of Holocaust survivors were found to be three times more likely to develop post-traumatic stress disorder if they were exposed to a traumatic event than demographically similar Jewish people whose parents did not survive the Holocaust.
Researchers found that children of Holocaust survivors had the same neuroendocrine or hormonal abnormalities that the Holocaust survivors and other people suffering from post-traumatic stress disorder had.
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"The gene changes in the children could only be attributed to Holocaust exposure in the parents," Dr. Rachel Yehuda, who led the study, determined.
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The research examined "epigenetic inheritance" - a theory asserting that environmental influences like smoking, weight loss and pressure could affect the genes of one's children and even grandchildren.
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While the scientific convention is that only genes that are included in one's DNA could transmit biological information from one generation to the next, genes do change based on the environment on a regular basis, through chemical marks that attach themselves onto one's DNA.
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Past research showed that some of these chemical marks are passed on to the next generation, which shows that the environment can influence the health of the unborn child.
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3. English More Celtic than Anything Else
British Origins (Leslie et al. 2015)
http://dienekes.blogspot.co.il/2015/03/british-origins-leslie-et-al-2015.html
Stephan Schiffels, Wolfgang Haak, Pirita Paajanen, Bastien Llamas, Elizabeth Popescu, Louise Lou, Rachel Clarke, Alice Lyons, Richard Mortimer, Duncan Sayer, Chris Tyler-Smith, Alan Cooper, Richard Durbin
http://dx.doi.org/10.1101/022723
Iron Age and Anglo-Saxon genomes from East England reveal British migration history
... we find that today's British are more similar to the Iron Age individuals than to most of the Anglo-Saxon individuals, and estimate that the contemporary East English population derives 30% of its ancestry from Anglo-Saxon migrations, with a lower fraction in Wales and Scotland.
... the British are, overall, a very homogeneous population... the authors are able to detect 17 main clusters of the British.
Most of the clusters are geographical, but some span different regions.