Distant Ancestors

In my never-ending quest to get my science knowledge a little more up-to-date (the better to write science fiction), I periodically surf the net in search of interesting but not too complicated science articles. This past week, I ran across quite a few articles about Neanderthals; when they died out, where they died out, why they died out, and so on.

You know about the Neanderthals; big heavy brows, broad flat noses, short chunky bodies. All those characteristics were helpful to them as they lived in Europe during ice age conditions. I don't remember how the heavy brows were helpful, but the noses helped warm the frigid air before it hit their lungs, and their compact bodies conserved body heat.

Up until recently, it was believed that the last of the Neanderthals died out in the area of Spain about 40-42,000 years ago, helped along on the road to extinction by the arrival of 'modern man' into Europe shortly before the demise of the Neanderthals. It wasn't certain that the two groups came into direct conflict and poked holes into one another, but if nothing else, they were both vying for the same food supply, and it was thought Neanderthals just couldn't effectively compete.

According to what I read this week, a new dating technique for old skeletons and other remains has now pushed the demise of the Spanish Neanderthals to around 50,000 years ago. So, were they completely gone before 'modern man' arrived? Probably not. The scientists were going to be conducting more tests on other sites, but it was rather expected that the new dating technique would also push back the date of modern man's arrival into Europe a similar amount of time. So, other than changing the position of a couple dots on a timeline, this didn't really change much.

On the other hand, genetic anthropologists have been analyzing tiny bits of Neanderthal DNA wherever they could find it, and by combining the results of all their work, they figure they've got about 12% of a complete Neanderthal DNA workup.

And it seems Jean Auel was correct when she wrote in Clan of the Cave Bear that Neanderthals and modern man had babies together. Scientists have compared current DNA to Neanderthal DNA and found that modern people have as much as 2% of their DNA from Neanderthals. The amount varies between ethnicities, but it's there.

So... I blame my son's unibrow on Several-times-great-grandfather Oogh, of the German Neanderthals.

Who's Your Distant Ancestor?

Back when I was in grade school, I remember one of my sisters preparing a display for her high school science fair project. In that project, she compared Neanderthals to Cro-Magnons. I don’t remember what kind of grade she received, but I found her project fascinating. Two types of humans, living at the same time! I wondered what their interactions would have been like.

Since then, the same question has been explored in various medias. Jean Auel’s Clan of the Cave Bear made a big splash with readers as it followed the life of a young Cro-Magnon, also known as a modern human, who was raised by Neanderthals, if I remember correctly. Various educational shows on TV have been made about the Neanderthals, the Homo Sapiens, how they were different, how they were alike, and how they might have interacted before the Neanderthals died out.

The impression I’ve gotten over all these years was that scientists didn’t feel these two species of humans had interbred, and I wondered why they thought that way. Neanderthals are depicted as kind of squat, hairy, with a heavy brow, broad noses and receding chins. I could look around and see people who had those attributes, although it’s usually one per person, not all of them. But no, it seemed we were determined to blame our own ancestors for killing the last of the Neanderthals.

At last, a skeleton has been discovered in northern Italy that appears to be that of a mixed breed. Although mostly that of a modern human, the jaw displays a receding chin. The DNA reveals this person had Neanderthal mitochondrial (maternal) DNA. So it would seem the two species did interbreed, at least once.

Which opens up a whole new mess of ancient ancestors we didn’t realize were in the gene pool.

Sometimes when I’m working out the background for a story, I pick 2 or 3 genetic things to track throughout the population and then work out how those attributes manifest in the population over the generations. The gene for dark hair, for instance, will dominate a gene for lighter hair, and blond will dominate red hair. But after a few generations of almost all the people having dark hair, you will start getting a generation or two of lots of blonds, and a few redheads will crop up. The number of blonds will ebb and flow; the number of redheads tends to remain fairly steady.

I never thought to track the occurrence of receding chins.