You’d think that the ease of world travel would have an homogenizing effect on the human species, but new research suggests that the residents of various continents are becoming increasingly different from each other.
If evolution had been proceeding steadily at the current rate since humans and chimps separated 6 million years ago there should be 160 times more differences than the researchers found.
That indicates that human evolution had been slower in the distant past, Harpending explained.
“Rapid population growth has been coupled with vast changes in cultures and ecology, creating new opportunities for adaptation,” the study says. “The past 10,000 years have seen rapid skeletal and dental evolution in human populations, as well as the appearance of many new genetic responses to diet and disease.”
Obviously, even fairly rapid change won’t result in species differentiation for thousands of years, but we might wind up with Eloi and Morlocks yet.
One response to “Evolution May be Speeding Up”
Sure, the raw number of mutations is up because of a population exponentially in excess of previous ages and, possibly, increased exposure to toxins and radiation in the environment. But, the nature and direction of the statistically slim minority of favorable mutations that impact success in terms of reproduction has diverged from the traditional model. Success, in evolutionary terms, means increased capability to produce viable, fertile progeny in greater numbers. The pressures that favored, for example, intelligence, stamina, coordination, good eyesight, better pattern recognition, etc. are disappearing in the wake of modern medicine and prosthetic technology. Traditional models like “intelligence = success = wealth = better diet and increased reproductive longevity = the ability to produce and raise more fertile progeny” are disappearing. Birthrates are down in the wealthier nations and they’re up in poorer ares. The increased efficacy of famine relief and medical aid insure that more children in impoverished surroundings live to sexual maturity. In wealthier nations, government programs frequently help subsidize children born in unfavorable economic situations. All these things — hunger relief, medical aid, government subsidy of less fortunate children, etc. are undeniably good things, but they *do* change the dynamics of traditional human evolutionary models.
I don’t argue that human evolution isn’t continuing, even at an accelerated rate, but the traits being selected for in our current context are subtle and possibly surprising. What traits *are* likely to be evolutionary winners in the modern model?