“We aren’t the same as people even a thousand or two thousand years ago,” he says. Harpending theorizes that the attitudes and customs that distinguish today’s humans from those of the past may be more than just cultural, as historians have widely assumed. “We are getting less alike, not merging into a single mixed humanity.” “It is likely that human races are evolving away from each other,” says University of Utah anthropologist Henry Harpending, who coauthored a major paper on recent human evolution. Many of these DNA variants are unique to their continent of origin, with provocative implications. The mutations relate to the brain, the digestive system, life span, immunity to pathogens, sperm production, and bones-in short, virtually every aspect of our functioning.
The story of the human body : 7 transitions of human evolution skin#
The new genetic adaptations, some 2,000 in total, are not limited to the well-recognized differences among ethnic groups in superficial traits such as skin and eye color. Over the past 10,000 years, their data show, human evolution has occurred a hundred times more quickly than in any other period in our species’ history. They find an abundance of recent adaptive mutations etched in the human genome even more shocking, these mutations seem to be piling up faster and ever faster, like an avalanche. Yet a team of researchers has done just that. So to suggest that humans have undergone an evolutionary makeover from Stone Age times to the present is nothing short of blasphemous. “Our modern skulls house a Stone Age mind,” they wrote in a background piece on the Center for Evolutionary Psychology at the University of California at Santa Barbara. Even the founders of evolutionary psychology, Leda Cosmides and John Tooby, signed on to the notion that our brains were mostly sculpted during the long period when we were hunter-gatherers and have changed little since. Everything we’ve called culture and civilization we’ve built with the same body and brain.” This view has become so entrenched that it is practically doctrine. Since modern Homo sapiens emerged 50,000 years ago, “natural selection has almost become irrelevant” to us, the influential Harvard paleontologist Stephen Jay Gould proclaimed. Fossil evidence shows that Neanderthal prey, including wooly mammoths, may have shifted their range further south, leaving Neanderthals without their preferred foods.For decades the consensus view-among the public as well as the world’s preeminent biologists-has been that human evolution is over. There are several theories for their extinction.Īround 40,000 years ago, the climate grew colder, transforming much of Europe and Asia into a vast, treeless steppe. Neanderthals went extinct in Europe around 40,000 years ago, roughly 5,000 to 10,000 years after first meeting Homo sapiens. Neanderthals were already adapted to the climate of Eurasia, and some experts think Neanderthal DNA may have conveyed some advantage to modern humans as they exited Africa and colonized points north. Neanderthals had been living in Europe and Asia for hundreds of thousands of years when modern humans arrived. These include hair color, skin tone and sleeping patterns. Some of the Neanderthal genes that persist in humans today may influence traits having to do with sun exposure.
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That’s because the two species did not meet-and mate-until after modern humans had migrated out of Africa. Indigenous Africans may have little or no Neanderthal DNA. People of European and Asian descent have an estimated 2 percent Neanderthal DNA. Today, most people living outside of Africa have trace amounts of Neanderthal DNA in their genomes.
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These matings introduced a small amount of Neanderthal DNA into the human gene pool.