As part of a working group sponsored by the National Evolutionary Synthesis Center in Durham, NC, the team of researchers decided to find out if natural selection — a major driving force of evolution — is still at work in humans today. The result? Human evolution hasn’t ground to a halt. In fact, we’re likely to evolve at roughly the same rates as other living things, findings suggest.
Taking advantage of data collected as part of a 60-year study of more than 2000 North American women in the Framingham Heart Study, the researchers analyzed a handful of traits important to human health. By measuring the effects of these traits on the number of children the women had over their lifetime, the researchers were able to estimate the strength of selection and make short-term predictions about how each trait might evolve in the future. After adjusting for factors such as education and smoking, their models predict that the descendents of these women will be slightly shorter and heavier, will have lower blood pressure and cholesterol, will have their first child at a younger age, and will reach menopause later in life.
“The take-home message is that humans are currently evolving,” said Stearns. “Natural selection is still operating.”
Sadly, the article does not mention exactly what those emerging traits were naturally selected for…
There is still a lot of debate about how the changes in human habitation of the planet have influenced our rate of evolution. In contrast to the article quoted above, there are those who speculate that our evolution rate is actually increasing.
“We are more different genetically from people living 5,000 years ago than they were different from Neanderthals.”
John Hawks -University of Wisconsin anthropologist
In a fascinating discovery that counters a common theory that human evolution has slowed to a crawl or even stopped in modern humans, a study examining data from an international genomics project describes the past 40,000 years as a time of supercharged evolutionary change, driven by exponential population growth and cultural shifts.
A team led by University of Wisconsin-Madison anthropologist John Hawks estimated that positive selection just in the past 5,000 years alone -dating back to the Stone Age - has occurred at a rate roughly 100 times higher than any other period of human evolution. Many of the new genetic adjustments are occurring around changes in the human diet brought on by the advent of agriculture, and resistance to epidemic diseases that became major killers after the growth of human civilizations.
The findings may lead to a very broad rethinking of human evolution, especially in the view that modern culture has essentially relaxed the need for physical genetic changes in humans to improve survival.
Interesting if true. I know women hate being equal sized to men. I wonder if there is some pressure pushing women to be smaller? I just assumed that the latest generation of women being smaller was a result of the relatively poor nutritional value of fashionable diets. Personally, women under 5’5"~5’4’ are starting to get short. Under 5’1" or so is very small.
I can’t find the link to back it up, but I believe both sexes are getting taller, I recall an article where some american chap of average height heads out to one of the scandinavian countries, and tries to pickup women. He fails utterly as he is barely seeing eye to eye to most of them.
I’d be interested in looking at evolution from a city / suburbran / rural perspective. I live in a rural area, work in a suburban area (eg, not a lot of pollution / smog)…when I was in LA a few years ago, I really had a bad reaction and wondered if people who are living in LA for generations are evolving to handle the smog / pollution. I wonder how the lungs on a 3rd or 4th generation LA person differs from somone in a more rural area.
My 5’10" 21 year old daughter also laughs at it. I’m not sure what we fed our kids. My oldest boy is 6’4" and my twin 18 year old boys are 6’1". I’m 5’11" and their mother is 5’6".
Is the depletion of the ozone layer allowing more gamma rays through? Maybe that’s it.
