Javier Trueba/MSF, via Science Source
Carl Zimmer has an interesting article about genetics over on his Origins column at the New York Times. A recent paper in the journal Genome Biology and Evolution derails generic research that suggests some of our circadian traits might come from Neanderthal genes. Modern humans and the ancient humans that became Neanderthals diverged about 700,000 years ago, when a group of humans migrated north into Europe. Those humans later split into two groups with the Neanderthals in the west and the Denisovans in the east.
About 400,000 years ago, the population split in two. The hominins who spread west became Neanderthals. Their cousins to the east evolved into a group known as Denisovans.
The two groups lived for hundreds of thousands of years, hunting game and gathering plants, before disappearing from the fossil record about 40,000 years ago. By then, modern humans had expanded out of Africa, sometimes interbreeding with Neanderthals and Denisovans.
And today, fragments of their DNA can be found in most living humans.
Research carried out over the past few years by John Capra, a geneticist at the University of California, San Francisco, and other scientists suggested that some of those genes passed on a survival advantage. Immune genes inherited from Neanderthals and Denisovans, for example, might have protected them from new pathogens they had not encountered in Africa.
