Rule Five Friday

2014_02_21_Rule Five Friday (1)Meet Svante Pääbo.  Who is he and why is he interesting?  He’s the Neandertal Hunter, and he’s uncovering some fascinating new information on what makes up modern humans – at least those of us of European, Asian and Middle Eastern descent.

That information?  Neandertal DNA.  Excerpt:

Fired by his early success, Pääbo announced, in 2006, his group would sequence a full Neanderthal genome made of nuclear DNA within two years. In the end, the project was beset by tribulations – contamination, dastardly tricks by rival geneticists, dwindling supplies of Neanderthal bone – and Pääbo was more than a year late in completing the project.

2014_02_21_Rule Five Friday (2)His results provided a shock for both researchers and the public. When he compared his newly created Neanderthal genome with those of modern humans, he found a small but significant overlap in many of them. About 2% of Neanderthal genes could be found in people of European, Asian and far eastern origin. People from Africa had no Neanderthal genes, however. “This was not a technical error of some sort,” Pääbo insists. “Neanderthals had contributed DNA to people living today. It was amazingly cool. Neanderthals were not totally extinct.”

Most scientists, including Pääbo, now account for this result by arguing that modern humans – when they first emerged from Africa – encountered and mated with Neanderthals in the Middle East. Their offspring carried some Neanderthal genes and as modern humans swept through Asia and Europe they carried these genes with them.

2014_02_21_Rule Five Friday (3)There’s a down side, apart from the effect of the Neandertal genes on a couple of my cousins; as Pääbo’s work has uncovered, those genes may also be the cause of some chronic diseases:

Just what that input of Neanderthal DNA has done for Homo sapiens’s evolution is less clear. Pääbo speculates that changes in sperm mobility and alterations in skin cell structure could be involved. In addition, US researchers have recently proposed that Neanderthals passed on gene variants that may have had a beneficial effects in the past but which have now left people prone to type 2 diabetes and Crohn’s disease. “This is work that is going to go on for years,” he adds.

So what’s the upshot of these findings, when we seek to get a little insight into human behavior?  That’s simple:

2014_02_21_Rule Five Friday (4)Sex.  (Thus making this a great topic for a Rule Five Friday post.)

Humans like sex.  And sometimes – maybe much of the time – they aren’t too picky about who they have sex with.

The Neandertal were a controversy for many years.  Initially the preponderance of opinion was that smarter, more adaptable H. sapiens crowded the Neandertal out of Europe and the Levant.  A few enigmatic skeletons seemed to combine modern human and Neandertal features, but none of them were conclusive.

But now we have genetic evidence.   If your ancestry is European, Asian or Middle Eastern, you likely have some Neandertal DNA.  Interesting stuff.

2014_02_21_Rule Five Friday (5)Oh, and Pääbo’s work also uncovered an entire new species of early human – the enigmatic Denisovans.  (To be fair the discovery was made by Russian archaeologists from the Institute of Archaeology and Ethnology of Novosibirsk, but Pääbo did the genetic analysis that established them as a distinct form.)

It’s a fascinating time to be working in paleoanthropology – or even have it as a particular interest.

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