DNA shows humans & Neanderthals mated

[Hum]

A decade after scientists first cracked the human genome, scientists announce in the May 7 issue of Science that they have done the same for Neanderthals, the species of hominid that existed from roughly 400,000 to 30,000 years ago, when their closest relatives, early modern humans, may have driven them to extinction.

Led by ancient-DNA expert Svante P??bo of Germany's Max Planck Institute for Evolutionary Anthropology, researchers reconstructed about 60% of the Neanderthal genome, by analyzing tiny chains of ancient DNA extracted from bone fragments of three female Neanderthals excavated in the late 1970s and early 1980s from a cave in Croatia. The bones are between 38,000 and 44,000 years old.

The genetic information turned up some intriguing findings, indicating, for instance, that at some point after early modern humans migrated out of Africa, they mingled and mated with Neanderthals, possibly in the Middle East or North Africa as early as 80,000 years ago. If that is the case, it would have occurred significantly earlier than scientists who support the interbreeding hypothesis would have expected.

Comparisons with DNA from modern humans show that some Neanderthal DNA has survived to the present day.

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[Growled Member]

So that's why some of my family act like they do. :p

[morebaker]

I should go shave my beard :laugh:

[Hum]

That explains Isaac Hanson :laugh:

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[+Fulcrum Subscriber¹]

After years of anticipation, the Neanderthal genome has been sequenced. It?s not quite complete, but there?s enough for scientists to start comparing it with our own.

According to these first comparisons, humans and Neanderthals are practically identical at the protein level. Whatever our differences, they?re not in the composition of our building blocks.

However, even if the Neanderthal genome won?t show scientists what makes humans so special, there?s a consolation prize for the rest of us. Most people can likely trace some of their DNA to Neanderthals.

?The Neanderthals are not totally extinct. In some of us they live on a little bit,? said Max Planck Institute evolutionary geneticist Svante P??bo.

Read More http://www.wired.com/wiredscience/2010/05/neanderthal-genome/#ixzz0oCM6OBXS

Source - Wired.com.

[Rigby]

Shouldn't this be obvious? We already know we had a common ancestor.

[User6060]

Considering we share like 99% of our genome with mice I'm not too impressed with this finding.

It would be better if they could ascertain if we interbred with Neanderthals or we killed them off in war in a battle for resources.

[zhangm Supervisor]

I read the actual paper in Science. They did a good job working with what DNA they had, and I think they did some serious controls to show that their data was not contaminated by human DNA.

It would be better if they could ascertain if we interbred with Neanderthals or we killed them off in war in a battle for resources.

They found that Neanderthals share more DNA markers with certain human populations than others. This could be evidence of genetic exchange between early humans and early Neanderthals, however, another explanation could be that natural selection positively selected for certain sets of genes in both human and Neanderthal populations. If gene flow did occur between the two populations, it did not occur on a large scale.

Anyway, one of the first things you learn in genetics is that its not what you have, but what you express. It is the pattern of gene expression that determines an organism's phenotype, rather than the content of its genome. As an oversimplified example, imagine that you buy two identical boxes of Legos. From the contents of one box, you assemble a boat. From the contents of the other box, you assemble an airplane. While the boat and the airplane are composed of the same building blocks, you can't say that the final products are identical.

Comparisons saying that humans are about 80% genetically identical to bananas is fairly meaningless when they have vastly different patterns of gene expression. Furthermore, mutating just a small subset of genes, such as those encoding transcription factors or other gene expression regulators (miRNAs, siRNAs, and splicing factors) can have a huge impact on the gene expression pattern of an organism.

A great paper applying this principle was published by Hal Alper in Science on Global Transcriptome Metabolic Engineering (Alper et al, 2006. Engineering Yeast Transcription Machinery for Improved Ethanol Tolerance and Production). It is a good read if you want an idea of how crazy-powerful genetic engineering and screening can be if you aim for the right targets.

[Growled Member]

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