Kissing cousins

Our view: If humans and Neanderthals have practically the same DNA, where do you draw the line?

May 15, 2010

You know those TV ads for car insurance that pitch switching policies to save money as something so easy that even a caveman could do it? Turns out those ad makers really knew their audience.

Scientists now say that new tests on ancient fossil bones show that modern humans and Neanderthals interbred tens of thousands of years ago — and that the results of those dalliances were fairly predictable: 1 percent to 4 percent of the human genetic code today can be traced back to those cave-dwelling ancestors.

The research, carried out at the Max Planck Institute for Evolutionary Anthropology and published in the journal Science, suggests that the Neanderthals, who died out around 30,000 years ago, were our kissing cousins on the evolutionary tree. Not only are they homo sapiens' closest hominid relatives, but, genetically speaking at least, they live on in modern humans today.

The DNA samples on which the study was based were painstakingly extracted from 40-century-old bones and compared with those of modern humans. The technology that made that possible represents an enormous scientific breakthrough, but more importantly, it may spur a revolution in thinking about our evolutionary forebears.

One of the Stanford researchers involved in the project was asked recently whether it would be possible to reconstitute Neanderthal DNA to, in effect, resurrect a member of an extinct species. The scientist replied that while such a procedure would involve formidable technical difficulties, the main obstacle would be an impossible moral and ethical dilemma: Do you put such an individual on display in a zoo — or send him or her to study at Stanford?

We don't know what drove the Neanderthals, who left Africa hundreds of thousands of years before modern humans did, to extinction. Perhaps they were less adaptable to environmental changes, or perhaps they were eventually overwhelmed by later-arriving human competitors.

Whatever the reason for their demise, on a genetic level, Neanderthals and modern humans are almost as closely related as today's ethnic groups are to each other — so close that today, scientists consider them virtually human in all essential respects.

No wonder the caveman in the TV ad took offense at the suggestion that he was any less adept than we are at finding the lowest rates on car insurance. He must have known in his bones that he is more like us than we think — and now we have the DNA to prove it.

—Glenn McNatt

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