Daily Archives: January 30, 2014

Neanderthal, human mixing had gene benefits, drawbacks

Posted: January 30, 2014 at 5:46 am

The amorous unions between modern humans and Neanderthals may have led to sons who weren't much good at fathering children themselves, a new study suggests. The findings hint that hybrid boys were partially infertile or perhaps entirely sterile due to the incompatibility of human and Neanderthal DNA. Bolstering those results, a second new study finds that some of the Neanderthal DNA that entered the human genome as a result of interbreeding seems to have made for more feeble offspring.

But both studies also find evidence that Neanderthals bequeathed useful DNA to humans ?? DNA that seems to have helped Homo sapiens adapt to new locales after they left their homeland in Africa. Whether the interbreeding was a net gain or a net loss for humans may never be determined, say the scientists involved.

"It's impossible to come to a simple conclusion like 'It was beneficial' or 'It was deleterious,' or 'It was not helpful,' " says University of Washington evolutionary geneticist Joshua Akey, an author of one of the new papers. "It was all of those things simultaneously. In different parts of our genome, (mixing) was advantageous. In other parts of our genome, it was not a good thing."

When modern humans moved out of Africa into Eurasia some 100,000 years ago, they found Neanderthals there to greet them. The two groups may have made war, but they certainly also made love. Today's Europeans and East Asians owe 1% to 2% of their DNA to Neanderthals, but the impact of those additions has been unclear.

To find out more, rival teams used different methods to conduct the first systematic surveys for Neanderthal genetic material in the DNA of modern humans. Despite their different techniques, both teams found evidence of Neanderthal DNA in genome regions involved with the production of keratin, a protein in skin and hair - a sign that the Neanderthal DNA was likely to have been beneficial. Perhaps the Neanderthal DNA helped make skin and hair more suitable for the Eurasian climate, or more resistant to the local germs. One set of findings was reported in this week's Nature, the other by Akey and a colleague in this week's Science.

Before modern humans arrived in Eurasia, "Neanderthals were living (there) for hundreds of thousands of years, and so they had genetics that were adapted to the environment," says statistical geneticist Sriram Sankararaman of Harvard Medical School, an author of the Nature paper. "Modern humans were moving into these same areas, and the genes they acquired from Neanderthals could have been beneficial." His group also found Neanderthal DNA in areas of the human genome that affect diseases such as type-2 diabetes, but the researchers can't say exactly how the Neanderthal genetic material affects human health today.

Both teams also found evidence that human-Neanderthal mating wasn't always good for the resulting children. Long stretches of DNA in living humans are devoid of Neanderthal DNA, suggesting it was purged from the human genome because of its negative effects. Perhaps offspring with the Neanderthal DNA were less likely to survive adulthood, or perhaps they were less likely to have children of their own. The Nature study indicates that some Neanderthal DNA, when introduced to the modern-human genome, led to male children with lower fertility.

That's a surprising result, says population geneticist Montgomery Slatkin of the University of California, Berkeley, who was not involved with the new research.

"I honestly thought (Neanderthals and modern humans) could interbreed freely, in the same way that different groups of modern humans can interbreed freely," Slatkin says. "And that is evidently not the case."

Instead the results "seem to confirm that Neanderthals and moderns were basically on separate evolutionary trajectories despite a little hanky-panky along the way," Ian Tattersall, curator emeritus at the American Museum of Natural History, says via e-mail.

Continue reading here:
Neanderthal, human mixing had gene benefits, drawbacks

Posted in Human Genetics | Comments Off on Neanderthal, human mixing had gene benefits, drawbacks

Neanderthal genes are in you

Posted: at 5:46 am

WASHINGTON Next time you call someone a Neanderthal, better look in a mirror.

Many of the genes that help determine most people's skin and hair are more Neanderthal than not, according to two new studies that look at the DNA fossils hidden in the modern human genome.

About 50,000 years ago, modern day humans migrated out of Africa north to Europe and East Asia and met up with furrow-browed Neanderthals that had been in the colder climates for more than 100,000 years. Some of the two species mated. And then the Neanderthals died off as a species except for what's left inside of us.

Scientists isolated the parts of the non-African modern human genetic blueprint that still contain Neanderthal remnants. Overall, it's barely more than 1 percent, said two studies released Wednesday in the journals Nature and Science.

However, in some places, such as the DNA related to the skin, the genetic instructions are as much as 70 percent Neanderthal and in other places there's virtually nothing from the species that's often portrayed as brutish cavemen.

- University of Washington genome scientist Joshua Akey

The difference between where Neanderthal DNA is plentiful and where it's absent may help scientists understand what in our genome "makes humans human," said University of Washington genome scientist Joshua Akey, lead author of the paper in Science.

Harvard researcher Sriram Sankararaman, the lead author of the Nature study, said the place where Neanderthal DNA seemed to have the most influence in the modern human genome has to do with skin and hair. Akey said those instructions are as much as 70 percent Neanderthal.

"We're more Neanderthal than not in those genes," Akey said.

However, Sankararaman cautions that scientists don't yet know just what the Neanderthal DNA dictates in our skin and hair.

Read more from the original source:
Neanderthal genes are in you

Posted in Human Genetics | Comments Off on Neanderthal genes are in you

KOTD – Rap Battle – DNA vs Eurgh – Collaborated – Video

Posted: at 5:46 am


KOTD - Rap Battle - DNA vs Eurgh - Collaborated

By: Sevil ien

See the article here:
KOTD - Rap Battle - DNA vs Eurgh - Collaborated - Video

Posted in DNA | Comments Off on KOTD – Rap Battle – DNA vs Eurgh – Collaborated – Video

Review HTC Droid DNA Nillkin Case3970 – Video

Posted: at 5:46 am


Review HTC Droid DNA Nillkin Case3970

By: Ayesha Henney

See the original post:
Review HTC Droid DNA Nillkin Case3970 - Video

Posted in DNA | Comments Off on Review HTC Droid DNA Nillkin Case3970 – Video

DNA Fingerprinting – Video

Posted: at 5:46 am


DNA Fingerprinting
Source: http://highered.mcgraw-hill.com/sites/dl/free/0072835125/126997/animation40.html.

By: juvedelinhm

Read more:
DNA Fingerprinting - Video

Posted in DNA | Comments Off on DNA Fingerprinting – Video

Sachin DNA Sample – Video

Posted: at 5:46 am


Sachin DNA Sample
Sachin Tendulkar provides a swab of his DNA for the Official Sachin Tendulkar Opus at the Press Announcement of his Opus, the Opus Store, Covent Garden.

By: thisisopus

Read more:
Sachin DNA Sample - Video

Posted in DNA | Comments Off on Sachin DNA Sample – Video

STOLEN BABIES "Filistata" live 10/22/13 @ DNA Lounge CAPITALCHAOSTV.COM – Video

Posted: at 5:46 am


STOLEN BABIES "Filistata" live 10/22/13 @ DNA Lounge CAPITALCHAOSTV.COM
http://www.facebook.com/CapitalChaos https://plus.google.com/u/0/b/118015811605522173893/118015811605522173893/photos http://www.capitalchaostv.com/ Stolen B...

By: Capital Chaos TV

More here:
STOLEN BABIES "Filistata" live 10/22/13 @ DNA Lounge CAPITALCHAOSTV.COM - Video

Posted in DNA | Comments Off on STOLEN BABIES "Filistata" live 10/22/13 @ DNA Lounge CAPITALCHAOSTV.COM – Video

DNA PREMIER – Video

Posted: at 5:46 am


DNA PREMIER
World premier of MAINBASE NEW MUSIC DNA on Irie fm JAMAICA https://www.facebook.com/BlueFlamesEntertainment?ref=hl.

By: Marlon Clarke

See more here:
DNA PREMIER - Video

Posted in DNA | Comments Off on DNA PREMIER – Video

Neanderthal DNA lives on in modern humans, research shows

Posted: at 5:46 am

The ancestors of most modern humans mated with Neanderthals and made off with important swaths of DNA that helped them adapt to new environments, scientists reported Wednesday.

Some of the genes gained from these trysts linger in people of European and East Asian descent, though many others were wiped out by natural selection, according to reports published simultaneously by the journals Nature and Science.

The stretches of Neanderthal DNA that remain include genes that altered hair and pigment, as well as others that strengthened the immune system, the scientists wrote. Together, they offer intriguing hints about how Neanderthal genes may have helped humans adapt as they spread around the globe.

They also add to evidence that Neanderthals linger in us, about 30,000 years after they mysteriously vanished.

"They are not fully extinct, if you will," said geneticist Svante Paabo of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, a coauthor of the Nature study. "They live on in some of us today a little bit."

Genes controlling keratin, a key component in the development of skin and hair, stand out as the strongest Neanderthal signal in a modern genome, Paabo said. Precisely how these may have helped change modern physical characteristics remains unresolved, he added.

The new studies confirm earlier findings that modern humans did more than bump elbows with Neanderthals when they encountered them after they left Africa.

An estimated 1% to 3% of the human genome comes from Neanderthals, suggesting that members of the two species mated perhaps 300 times about 50,000 years ago, said Joshua M. Akey, a population geneticist from the University of Washington and lead author of the study published in Science. There's no way to tell whether those encounters happened about the same time or were spread out over many generations, he said.

"Individually, we are a little bit Neanderthal," Akey said. "Collectively, there is a substantial part of the Neanderthal genome that's still floating around in the human population that's just shattered into different pieces, and everyone has slightly different parts."

Confirming that there are slivers of Neanderthal DNA in modern humans is one thing; knowing what effect it had on us is another, said UC Berkeley biologist Montgomery Slatkin, who has done similar research on Neanderthal genetics but was not involved in either study. "Now there is convincing evidence that indeed some [genes] were selected in humans."

Read the original here:
Neanderthal DNA lives on in modern humans, research shows

Posted in DNA | Comments Off on Neanderthal DNA lives on in modern humans, research shows

Neanderthal Genes Found in Modern Human DNA, Studies Find

Posted: at 5:46 am

Neanderthals that have been extinct for 28,000 years live on in human DNA, according to research suggesting the genes may help us better survive cold weather and be linked to some present-day diseases.

The Neanderthal genes make up only about 2 percent to 4 percent of the DNA carried by a given human today, according to a paper published in the journal Science. Even so, it may be linked to the development of our hair and skin, as well as to immune disorders such as Type 2 diabetes, the research found.

New DNA techniques are reshaping knowledge of human evolution just as quickly as theyre sparking the development of medical tests and treatments. Thats allowing scientists to peek into history by comparing modern DNA with the Neanderthal genome, recently reconstructed by scientists using material from the toe bone of a female who lived 50,000 years ago.

Were not as beholden to ancient DNA anymore, said Joshua Akey, an associate professor of genome science at the University of Washington in Seattle, and an author of one of the studies. Rather than excavating bones, we can now excavate DNA from modern individuals.

Akeys study identified the skin and hair traits. A second report yesterday by scientists at Harvard Medical School in Boston and the Broad Institute in Cambridge, Massachusetts, found nine links between Neanderthal DNA and previously identified human genes, some of which affect immune function.

The Neanderthal DNA found in the ancient toe bone was reported in the journal Nature in December. That study suggested inbreeding may have been common for Neanderthals, and may have led to their demise. Earlier studies using less complete genetic profiles determined that Neanderthals probably mated with ancient humans as well.

The latest DNA research supports that conclusion and suggests the Neanderthal genes left behind as a result may have aided humans in adapting to non-African environments, Akey said, adding, Whats striking is you can really look at the distribution of Neanderthal DNA across the entire genome.

Both studies published yesterday identified significant areas within the human genome where no Neanderthal genes appear, more than would be anticipated by chance. That suggests some mutations werent passed on, probably because they didnt help survival.

The shared genes that influence hair and skin traits also influence other things, Akey said. Its possible, for instance, that the Neanderthal genes helped alter pigmentation and moisture retention in humans, helping to increase body warmth in colder climates.

The Harvard study found that genes that are most active in the testes and those in the X chromosome have the least Neanderthal influence, compared to other parts of the genome. The pattern may have been a way for the body to naturally overcome infertility among different species.

Continued here:
Neanderthal Genes Found in Modern Human DNA, Studies Find

Posted in DNA | Comments Off on Neanderthal Genes Found in Modern Human DNA, Studies Find