Posted on 12/19/2013 12:22:35 PM PST by 2ndDivisionVet
A high-quality genome sequence obtained from a female Neanderthal toe bone reveals that the individual’s parents were close relatives and that such inbreeding was prevalent among her recent ancestors, according to a paper published today (December 18) in Nature. But the sequence also reveals that interbreeding occurred between Neanderthals and other hominin groups, including early modern humans.
“Did humans evolve like a constantly branching tree? A lot of people think so,” said Milford Wolpoff, a professor of anthropology at the University of Michigan, who was not involved in the study. “But there’s also been this thread of thought, by some people like me, that humans evolved more like a network, where there are different populations and they split and sometimes they come back together and they mate.” The new toe bone sequence data, he said, is “really important because it’s giving us good evidence that there’s been constant interbreeding between different human groups all through prehistory.”
The toe bone was found in a cave in Denisova, Siberia, where the conditions for DNA preservation are near-perfect. “The cave year-round has an average temperature of zero degrees Celsius and that’s probably helping to contribute to the preservation,” explained John Hawks, a professor of anthropology at the University of Wisconsin, who also did not participate in the study.
Indeed, the toe bone and its DNA were so well preserved that it was possible to obtain sequence data that “is on the same level, as far as quality goes, as many other modern human genomes,” said Kay Prüfer, an evolutionary geneticist from the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, who led the study. “For every position in the genome we have on average 50 fragments covering it, which is amazing,” he said. Just how amazing? Previously sequenced Neanderthal genomes have average coverages of 0.5 to 1.3.
Also amazing, was the fact that the toe bone was Neanderthal at all. Previous bone and tooth samples found in the cave had yielded high-quality DNA sequences identified as belonging to a new and different group of hominins called the Denisovans, who were named after the location. “We were expecting that it [the toe] would be another Denisovan,” said Prüfer, “but, to our surprise, it wasn’t.”
Another surprise followed. The high degree of coverage allowed the team to observe subtle sequence differences that were present in the maternal and paternal copies of the chromosomes. But “what we actually saw was that there are long stretches where the two copies of the chromosomes were actually very, very similar,” said Prüfer, “and that essentially means that the two parents must have been closely related.” From the team’s calculations, the parents were likely half siblings, an uncle and niece, or similar. And further sequence analysis indicated that inbreeding had been typical among the individual’s recent ancestors. In fact, the level of variation “was among the lowest observed for any organism,” Prüfer said.
Despite the high degree of inbreeding that took place in the family of this particular Neanderthal—named the Altai Neanderthal—there was also evidence that Neanderthals in general interbred with other hominin groups. The team compared the genomes of the Altai Neanderthal, a Denisovan, a number of modern humans, and Neanderthals from Croatia and the Caucasus mountains, and confirmed earlier indications that modern humans contain both Neanderthal and Denisovan DNA.
They also showed that Denisovans contained both Neanderthal DNA sequences—most similar to that from the Altai Neanderthal—and sequences absent from Neanderthals and modern humans, which thus appear to have come from an unknown archaic hominin group.
“The general picture is that we have lots of different admixtures. So we see that any type of human group . . . seems to have some exchange of [genetic] material with another group,” Prüfer said.
Besides revealing the complexities of ancient hominin mating habits, the high-quality Neanderthal and Denisovan genomes should also help scientists better understand modern humans, said Prüfer. “We can now ask: What are the variants on the human lineage that are definitely new and that we all have and. . . that enabled us to do certain things that Neanderthals and Denisovans didn’t accomplish, including growing to now seven billion people, living all over the planet, and having airplanes to go from A to B? If there is some genetic basis to that, then it is hidden in these changes,” he said.
The good news, said Hawks, is that such genetic changes are few. “There is not that much that sets modern humans apart from these ancient people . . . and that’s a pretty cool message,” he said.
K. Prüfer et al., “The complete genome sequence of a Neanderthal from the Altai Mountains,” Nature, doi:10.1038/nature12886, 2013.
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My guess doggy style...
After getting a degree and graduate studies in Anthropology, I’ve come to the conclusion re this article that the best summation of the DNA evidence is that the human male’s policy was, “if it moves, screw it”.
I didn’t waste 6 years of school and money for nuthin’.
Thanks. Very interesting. Tough sell to the Navaho.
If I understand correctly, neither Neanderthal or Denisovians would be classed as modern humans.
What about the gay, lesbian, bisexual, and transgendered early ancestors of modern man????? we’re talking about only the heterosexual aspects of their behaviors??? Isn’t that bigoted????
Whoops! Thanks SteveH!
The heterosexual aspect is the only relevant consideration for heredity and subsequent humans.
Seduction is for sissies. A He-Man like his rape.
Blazing Saddles clip
http://www.youtube.com/watch?v=2_urvjCXg6c
global warming is a hoax.
Global warming is NOT HOAX...
The scam part of it is attributing it to human activities..
The global has been warming AND cooling for millions of years..
AT least ten of thousands.. (verified)..
global warming is a hoax
and man(capitalism) affecting the climate is also a hoax
anthropogenic global warming
global warming is a hoax
it’s getting colder not warmer . check out the Sun’s solar cycle 24 and 25 and see what is happening
10 Headlines Show Why Global Warming Alarm Is Bunk
The alarmists moved on from “global warming” to “climate change” because it was obvious that not only was the world not getting hotter, winter kept arriving with intense cold and mountains of snow
• “Record low temperature recorded in Antarctica: scientists” — Chicago Tribune, Dec. 9
• “National Weather Service says stretch of Arctic temperatures coldest since 1972” — Minneapolis Star Tribune, Monday
• “Al Gore wasn’t even warm about the disappearance of Arctic ice” — New Jersey Star-Ledger, Sept. 16
• “Scientists: Antarctic set record cold temperatures” — examiner.com, Dec. 10
• “Study: Earth was warmer in Roman, Medieval times” — Daily Caller, Friday
• “Global warming? Satellite data shows Arctic sea ice coverage up 50 percent!” — Daily Caller, Monday
• “Cairo Witnesses First Snowfall in 112 Years” — Pakistan Tribune, Sunday
• “Over half the USA covered in snow, the most in 11 years” — wattsupwiththat.com, Monday
• “Are tornadoes getting stronger? No” — wattsupwiththat.com, Sunday
HEY!
Lighten up Francis.
It gets warmer, it gets cooler, it gets warmer, it gets cooler. It's done this all by itself, and forever.
Now saying it's getting warmer WHEN it's actually getting cooler...that is a hoax.
there is no warming
and the slowing of the Sun’s solar cycle indicates more cooling to come
it’s cooling not warming so global warming is a hoax . that is why your news media changed the name of it to climate change
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