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listopencil 03-19-2013 10:31 AM

Hillbilly Cavemen
 
Prehistoric Human Skull Shows Signs of Inbreeding

http://blogs.smithsonianmag.com/scie...03/CT-scan.jpg

In 2010, the surprising discovery that Neanderthals likely crossbred with our ancestors tens of thousands of years ago generated headlines around the world.

Now, we have a new finding about the sex lives of early Homo sapiens: It looks like they engaged in some inbreeding as well.

That is the conclusion of anthropologist Erik Trinkhaus of Washington University in St. Louis and Xiu-Jie Wu and Song Xing of the Chinese Academy of Sciences’ Institute of Vertebrate Paleontology and Paleoanthropology, based on a fractured 100,000-year-old skull excavated from China’s Nihewan Basin. Their finding, published yesterday in PLOS ONE, is that the skull shows evidence of an unusual genetic mutation that is likely the result of high levels of inbreeding.

The researchers used CT scanning and 3D modeling to join together for the first time the 5 pieces of the fractured skull—known as Xujiayao 11, named for the site where it was found back in 1977—and realized that it exhibited an unusual deformity. When the pieces are combined, they leave a hole on the crown of the skull, but there is no evidence that the fracture was caused by a traumatic injury or disease. As a result, they consider it most likely that the hole is a defect known as an enlarged parietal foramen.
Nowadays, this hole is mostly found in people with a particular pair of genetic mutations on chromosomes 5 and 11—most often a consequence of inbreeding—and occurs in about 1 of 25,000 live births. The mutation interferes with bone formation in the skull over the first five months of an infant’s life, when the pieces of the skull are supposed to fuse together to cover up the “soft spot.”

Given the tiny sample size of human skulls this old and the fact that similar kinds of genetic abnormalities have been seen so often in other prehistoric skulls—the researchers count 22 individuals with skull deformities discovered from this era—Trinkhaus thinks the simplest explanation is that small and unstable human populations forced our ancestors to inbreed.

If no inbreeding occurred, “the probability of finding one of these abnormalities in the small available sample of human fossils is very low, and the cumulative probability of finding so many is exceedingly small,” he said in a press statement. “The presence of the Xujiayao and other Pleistocene [2.6 million to 12,000 years ago] human abnormalities therefore suggests unusual population dynamics, most likely from high levels of inbreeding and local population instability.”


http://blogs.smithsonianmag.com/scie...enceinbreeding

WhiteWhale 03-19-2013 10:35 AM

Kinda figured as much.

Human kind almost went extinct more than once. Population bottle necking... founder effect... all names for various levels of inbreeding.

Dave Lane 03-19-2013 10:35 AM

The universe and humans are only 6,000 years old. Anyone knows that.

/DC forum

ptlyon 03-19-2013 10:37 AM

Of course they did, they didn't know any better

boogblaster 03-19-2013 10:37 AM

inbreedin' my fav game .. pumpkin .....

buddha 03-19-2013 10:39 AM

Arkansas is asking, "What's the big deal?"

listopencil 03-19-2013 10:40 AM

Why go down the creek when you can just go across the cave?

WhiteWhale 03-19-2013 10:43 AM

Quote:

Originally Posted by Dave Lane (Post 9513341)
The universe and humans are only 6,000 years old. Anyone knows that.

/DC forum

I'm an atheist. I just want to make that clear before I tell you to shut the **** up.

There is already a dumbass thread for you to troll creationists. I can't stand people who turn every science topic into that stupid circular argument.

Fish 03-19-2013 10:48 AM

You look mighty good in that loin cloth, sis.....

listopencil 03-19-2013 10:49 AM

Quote:

Originally Posted by WhiteWhale (Post 9513340)
Kinda figured as much.

Human kind almost went extinct more than once. Population bottle necking... founder effect... all names for various levels of inbreeding.

Yeah, you would think that a very primitive society would have substantially different "moral" standards than us. I hesitate to refer to it as a moral standard for those issues that you stated. This is where tribalism began, and survival of the tribe was the key imperative.

ptlyon 03-19-2013 10:50 AM

Quote:

Originally Posted by listopencil (Post 9513379)
Yeah, you would think that a very primitive society would have substantially different "moral" standards than us. I hesitate to refer to it as a moral standard for those issues that you stated. This is where tribalism began, and survival of the tribe was the key imperative.

So it was "Take one for the team, Honey"?

WhiteWhale 03-19-2013 11:00 AM

Quote:

Originally Posted by listopencil (Post 9513379)
Yeah, you would think that a very primitive society would have substantially different "moral" standards than us. I hesitate to refer to it as a moral standard for those issues that you stated. This is where tribalism began, and survival of the tribe was the key imperative.

Well, I mean the founder effect can be seen in a lot of closed communities. It's the reason Amish people are usually born with an extra finger. I think morals went as far as empathy and protecting the tribe. In smaller communities in America it's not as uncommon as you think for people to marry within their family tree. It usually takes a few generations before problems arise.

Also, I post this any time inbreeding comes up.

http://www.genealogyintime.com/Image...amily_tree.jpg

listopencil 03-19-2013 11:09 AM

Quote:

Originally Posted by WhiteWhale (Post 9513403)
Well, I mean the founder effect can be seen in a lot of closed communities. It's the reason Amish people are usually born with an extra finger. I think morals went as far as empathy and protecting the tribe. In smaller communities in America it's not as uncommon as you think for people to marry within their family tree. It usually takes a few generations before problems arise.

Also, I post this any time inbreeding comes up.

http://www.genealogyintime.com/Image...amily_tree.jpg

Man, and the NFL coaching trees are considered incestuous...

Radar Chief 03-19-2013 11:32 AM

It’s a damn shame we got the same last name,
dang girl why you gotta be related? /Mountain Sprout

CrazyPhuD 03-19-2013 12:18 PM

In those days it wasn't called inbreeding as much as inraping.


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