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  (Source: BBC)
New study offers strong genetic evidence in support of the hypothesis that humans and their close kin hooked up

With the sequencing of the Neanderthals (Homo neanderthalensis) genome, we discovered that 1 to 4 percent of genes of humans (Homo sapiens) matched those found in Neanderthals.  Notably, matching genes suggested Neanderthals likely were fair skinned with blond/red hair, while humans at the time appeared to mostly have dark skin and black/brown hair.
 
The hot question in the aftermath of that sequencing was whether these similarities occurred spontaneously or whether they were the result of our ancestors getting it on, technically speaking, with Neanderthals.
 
The interbreeding hypothesis is attractive due to geography if nothing else.  Namely, the locations with the last surviving Neanderthal populations (Scandinavia, the English isles) also happen to have the most prevalent rate of Neanderthal appearance genes (fair skin, blond/red hair) of anywhere in the world.
 
We felt this particular hypothesis to be quite compelling.  That Neanderthal glancing at you across the campfire might look a little odd at first, what with her fair skin, auburn hair, and angular cheekbones.  But get a couple of Stone Age beers in you and she starts to look like a perfect 10.

Stone Age beer
Stone Age beer likely played a key role in human and Neanderthal hook ups.
[Image Source: Asle Rønning]

Now evolutionary geneticists with the University of Edinburgh and the Wageningen University (Netherlands) have published an impressive study in the peer-reviewed journal Genetics that indicates that's indeed how the genetic similarity likely arose.
 
The new study comes in response to a 2012 study in the Proceedings of the National Academy of Sciences by Anders Eriksson and Andrea Manica of the University of Cambridge.  That study acknowledged the interbreeding possibility, but argued in favor of an alternative -- sustained substructure.  According to that theory, certain subpopulation of each group retained traits, or evolved traits in parallel, via random mutations.
 
But Professor Laurent Frantz of Wageningen University calls that idea "unparsimonious" (too theoretically complex/violating Occam's razor).  He and his UK colleague did a more thorough analysis of known human mutation rates and genetic variance, plus looked at population distribution and other factors.  The results, he states, show a resounding win for the interbreeding hypothesis, while leaving the door open to the possibility that some common genes did come from sustained substructure.

Neanderthal chuck norris
Likely not a coincidence: apparently Neanderthals looked a lot like Chuck Norris.
[Image Source: BBC]

Professor Frantz was the study's senior author, UK Professor Konrad Lohse was the first author.  Professor Frantz comments to The Verge:

We did a bunch of math to compute the likelihood of two different scenarios.  We were able to do that by dividing the genome in small blocks of equal lengths from which we inferred genealogy.

Our analysis shows that a model that involves interbreeding is much more likely than a model where there was sustained substructure in Africa.  [Substained substructure might have contributed to genetic commonality] but it cannot be used to explain the genetic similarities [alone].

There seemed to be something that has gone wrong [in that study] because it seems unparsimonious... When we tested two hypotheses, we got a high support for a scenario where humans and Neanderthals interbred.

There have been a lot of arguments about what happened to these species.  Some think that we outcompeted [other hominins] or that they were killed by humans, but now we can see that it's not that simple.  Human evolution is much more complex than we previously thought.

In other words, why would early man, struggling to survive against nature and competing tribes, waste resources on killing and driving out Neanderthals? They could instead ally with them, recruiting the close relative to join the tribe.

neanderthal skull
Geneticist Svante Pääbo, one of the men who helped sequence the Neanderthal genome peers at the fossilized remains of his possible ancestor. [Image Source: Frank Vinken]

It's a compelling notion indeed.  So crack open a cold beer; chances are your ancestors were doing the same on one fateful night some 500,000 years ago.  Thanks to them, now that Neanderthal isn't just your close phylogenetic kin, it's also your direct ancestor.

Sources: Genetics, The Verge



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RE: is anybody surprised?
By purerice on 4/14/2014 3:00:15 AM , Rating: 2
No, evidence does not point to such violence as the most likely explanation for Neanderthals' disappearance.
A single Neanderthal jawbone showed scratches similar to that of deer hunted by humans.

It could have been post-death cannibalism.
It could have been botched surgery.
It could have been a nasty fall.
It could have been an autopsy.
It could have been a single murder.
It could have been punishment for a crime.
It could have been Neanderthal on Neanderthal.

Let us look at the facts and employ Occam's Razor. Neanderthals were bigger, smarter, had better "technology", and were native to the environment. A violent end to their race at the hands of smaller, weaker, dumber, primitive race seems highly unlikely. More likely is that they were out-bred, kind of like African and west-Asian immigrants in Europe out-breeding the natives today.


RE: is anybody surprised?
By Reclaimer77 on 4/14/2014 8:53:29 AM , Rating: 1
The fact that you just said Neanderthals were smarter than homo sapiens, twice, ruins any credibility in this discussion you might have had.

Within a thousand years of the appearance of man, the Neanderthal race was completely extinct.


RE: is anybody surprised?
By Jeffk464 on 4/14/2014 11:59:51 AM , Rating: 2
Last show I watched they were thinking climate change led to their extinction. Neanderthals were better adapted to the cold and were better at hunting at close quarters in dense forests. We were better at hunting on open grasslands. Neanderthal were more robust and had brute strength, we had speed and agility.


RE: is anybody surprised?
By Jeffk464 on 4/14/2014 12:01:30 PM , Rating: 2
I'm pretty sure they also said that Neanderthal required 4X the calories that we do, that could be a pretty big disadvantage when things are scarce.


RE: is anybody surprised?
By woody1 on 4/16/2014 4:48:44 PM , Rating: 2
I never read any account that suggested that Neanderthals were more intelligent than Homo Sapiens. In fact, the opposite is the general consensus. Neanderthals are considered to lack language skills (or even the physical ability for language) and are considered to have had inferior tool-making skills. Sounds like you're trying to bend the facts to support your racist beliefs about inferior/superior races in current-day Europe.


RE: is anybody surprised?
By Silver2k7 on 4/17/2014 3:03:44 PM , Rating: 2
I belive some finds that have been attributed to homo sapiens such as tools and cave art etc have recently been proven to be much older and thus proven that Neanderthal was smarter than previously thought.


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