According to the Scientists, the speed of human evolution increased rapidly during the last 40,000 years — and it’s only going to get faster. The findings were published by a team of U.S. anthropologists in the Proceedings of the National Academy of Sciences, overturn the theory that modern life’s relative ease has slowed or even stopped human adaptation. Selective pressures are still at work; they just happen to be different than those faced by our distant ancestors. “We’re more different from people 5,000 years ago than they were from Neanderthals,” said study co-author and University of Utah anthropologist Henry Harpending. In the study, researchers analyzed genomes from 270 people belonging to four disparate ethnic groups: Han Chinese, Africa’s Yoruba tribe, Japanese and Utah Mormons. By comparing areas of difference and similarity, they determined that about seven percent of the genome has undergone significant change since the end of the last Ice Age. If human beings had always evolved at such a rapid clip, said the researchers, genetic differences between people and chimpanzees would be 160 times greater than they are. Driving the changes are environmental fluctuations and population growth. As the number of people swells, so do the number of mutations generated by random chance. Further selecting for disparate genetic inheritances are the diverse terrains, climates and social structures inhabited since the glaciers retreated.
The findings contradict the hypothesis that evolution must be slowing down because people who once would have died are sustained by modern medicine and social safety nets. They also suggest that genetic differences between different ethnic groups can be significant.
“The actual genes that are sweeping have not been thoroughly identified in all cases, but we can see interesting patterns,” said Harpending. “There are something like 6 genes, all broken African genes, responsible for European light skin, blue eyes, blonde hair. They are evolving fast in Europe. Meanwhile, other genes responsible for light skin are sweeping in Asia, and they are different from those in Europe.” Asked about James Watson’s controversial claims that intelligence evolved less effectively in people of African descent, Harpending said the study wasn’t designed to test such characteristics. He also cautioned against interpreting the findings as suggesting that people are becoming fundamentally better. “Some of the mutations let us do better. We can eat simple carbohydrates, which hunter-gatherers never did. But we may also be accumulating damaging stuff,” said Harpending. He wondered whether social changes might not cultivate unfortunate tendencies. “Evolution is a double-edged sword,” he said. “What evolution cares about is that I have more offspring. If you can do it by charming and manipulating, and I’m a hardworking farmer that’s going to feed the kids ten years down the road, then you’re going to win. Hit-and-run, irresponsible males are reproducing more. That isn’t good for anyone except those males, but that’s evolution.” The study’s ultimate message, said Harpending: “Whatever changes are happening, they’re happening faster.” Recent acceleration of human adaptive evolution wonder how humans might still evolve in a modern society, with all our medicines and what-not. For it to happen there would have to be some kind of selective pressure, either positive or negative. Positive pressure being something that allows us to have more kids, and negative pressure being something that kills us off before we reach breeding age. The only negative pressure that comes to my mind right away is car accidents. I think they kill more kids than any other single cause. It makes me wonder if somehow our species might evolve to become better drivers. Pure speculation! Evolution does not necessarily mean selection. Genes can become widespread in small or isolated populations simply through the operation of probability in breeding, regardless of whether the gene is “advantageous.” at least 2 of these groups – mormons and japanese – were very isolated. (and further, what were these genes, and what were their effect on phenotype, if any?) it’s premature to say these changes were definitively the result of “selective pressures,” but evolution = selection is a popular error these days. also, the last part of this article, about which mutations are “better,” “hit-and-run males,” is not science, is purely speculative, and should be given about the same weight as, for instance, the evolutionary theories you might hear from drunks at a bar any given night
It is breathtaking how quickly genes can sweep through modern populations and become “fixed.” That’s why nearly all Europeans are lactose-tolerant, even though this evolved in their ancestors only 5-6k years ago.
Just an old wives’ tale… We were all created by the Flying Spaghetti Monster. Pastafarian | Dec 10, 2007 5:23:19 PM Yikes…
James Watson is gloating today. Actually lactose tolerance is still in the minority by a long shot. I was just having an argument with a friend about Watson. Now he has more ammo. No! No more ammo for Watson in the study! Or at least very little. It measured a limited sample of just four ethnic groups, two of which (Japanese and Utah Mormon) are pretty blurry, and it didn’t look at genes related to intelligence, which are notoriously difficult to pin down and almost certainly far less important than environment. So, yes, it added to evidence that different groups can evolve differently — but jumping from this to meaningfully differential intelligences is a big, big jump. Like when Homer Simpson tried to jump the Springfield Gorge. Hit-and-run, irresponsible males are reproducing more. That isn’t good for anyone except those males, but that’s evolution.” How funny. Evolution is what got us here, after all. How funny that now we have experts who claim to know the difference between good and bad evolution. My feet hurt something terrible, when will we develop claws so we can hang from a tree? Anyone see “Idiocracy”? What the world will be like if we continue down this path of “evolution” led by hit and run males.
To have wunderkinds who are going to develop the next breakthrough in cellular biology) is trumping another (finding a spouse with low susceptibility to disease, crooked teeth, physical deformity). This is just fine for civilization, but were humanity to face some sort of collapse, humanity would be much more fragile. It also makes us more susceptible to mass pandemic diseases, like smallpox, influenza.
This is surely a blow to the “there is no such thing as race” argument. The authors are looking at genes that convey selective advantage. In order to reject mutations that spread by genetic drift, they only looked at alleles that occur in more than 22% of the population. My population genetics is a bit rusty, but they claim that this is strong evidence for selection. Furthermore, the candidate selected genes occur predominantly in genic regions, and preferentially include genes in functional classes that are plausible targets for recent adaptive changes. No neutral explanation, including population structure, can account for these features; only selection can.” That is, if it was just genetic drift, you’d see as many new alleles in junk DNA as in functional DNA, which isn’t the case. Also, they’re looking at a time frame of 10’s of thousands of years–the Mormons have only been isolated for a few generations. The Japanese may have been isolated for longer than that, but Japan is a pretty big place, and I don’t think genetic drift could spread a neutral mutation through the population in only 100 generations or so.
I’m not confident in our ability to determine whether traits are an advantage or not. For some of the reasons mentioned above. The many changes may even be effectively meaningless.
Lots of evidence that we are actually devolving! Take mac users for instance. If that chick in the sunglasses is wearing a Led Zeppelin t-shirt, I’d like to irresponsibly spread my genes with her. FAT UGLY PIGS ARE TENDING TO PROCREATE MORE OFTEN, HENCE THE WORLD WILL BE FILLED WITH… —->”TWO LEGGED PORKER PIGS” <—- Ever noticed how the most stupid, over weight members of society are too busy producing huge families while they live off of welfare. And notice how most of these parasites live in places like New Orleans? Fear NOT ! In 5-10 yrs huge leaps in technology will make it possible for a very small group of people to dictate who gets to breed and who gets turned into Soylant Green. There will be a huge cleansing of the human race with fascist overtones. So, enjoy these Last Days before you will be seen as unfit to spread your DNA. Few of us will be spared. The paper talks about genes, not traits. As far as I can tell, the authors don’t even have any idea what most (or all) of the mutations do. From that point of view, determining if a trait is an advantage is a matter of statistics, not judgment. We have a pretty good idea how fast a neutral gene will spread, so if something spreads significantly faster, it’s advantageous by definition. It’s funny, there’s so much emotion around issues of human evolution that it’s easy to slip into more philosophical discussions. (“What is an advantage? How can you say gene X is better than gene Y?”). Evolution is science, and science is about data–it’s probably more useful to think of an evolutionary advantage as just meaning that the dice are loaded, not that 2 is ‘better than’ 5. Pastafarian. Bless his noodly appendages. Asked about James Watson’s controversial claims that intelligence evolved less effectively in people of African descent, Harpending said the study wasn’t designed to test such characteristics.” What a neat little evasion! *Who* asked this question and why? Why is this little aside included in the article? It has seemingly no relevance to anything at all but some idiotic, ideologically racist claims made decades ago that have no validity whatsoever. Evolution has not moved forward at all. Except for the fact, that humans are becoming more resiliant to infections and illness’s… Apart from that, there is no proof, that evolution is indeed moving forward. If anything, yes its moving backwards… Less exercise (Tv,ps3’s), less human contact (computers, cellphones, chat rooms). There is only one thing to prove evolution… my XBOX 360 using HD! :).
At least the article is making some quite major errors. Claiming that evolution has not stopped due to medical advances, and basing that claim on genome changes from several thousand years, is just not tenable. If someone can show that there are increasingly large genomic changes happening in the last 150 years, then I could admit that medicine has not stopped evolution. But come on – people with asthma, allergies, or any of the more serious handicaps, would not have survived and breeded 200 years ago. They do now. So, in fact, genetic drift may very well be occuring, but it is probably making us as a species more handicapped and dependent on medical treatments. How about measuring noise? The article is *not* discussing natural selection. It is discussing the rate of genetic mutation, which can easily be (almost solely) explained by the huge population increases over the last 400 years. As far as genetic mutation goes, we have evolved. Perhaps due to the lack of *natural* selection, those evolved changes are not as apparent as they could otherwise be.
The theory of evolution is just that: a theory. No one really knows for sure how it works- this seems as good a theory as any. And modernized or not- our environment is still an environment and has its pressures and needs much as any other. One could assume that the genes that do well in that setting will be the ones that continue to press forward. Whether that’s really better than what we were at say, the turn of the 20th century is rather up in the air. We’ve got massive amounts of both positive and negative influences and some come from some pretty odd places.
From the actual paper: “Recent genetic drift including founder effects would affect all genomic regions equally, but the candidate selected genes occur predominantly in genic regions, and preferentially include genes in functional classes that are plausible targets for recent adaptive changes. Selection is the only explanation consistent with all these features.” “Hit-and-run, irresponsible males are reproducing more. That isn’t good for anyone except those males, but that’s evolution.” However, if the offspring of these males are less well looked after, surely *their* chances for offspring are reduced? It seems to me evolution applies here to selectively encourage the looking after of children. “Evolution has not moved forward at all. Except for the fact, that humans are becoming more resilient to infections and illness’s… Apart from that, there is no proof, that evolution is indeed moving forward. If anything, yes its moving backwards… Less exercise (Tv,ps3’s), less human contact (computers, cellphones, chat rooms)” Depends what you mean by forward. Physicaly, it could be said (in the west) we are getting worse. However…we have more mental stimulation than ever before. Those same video games and our intensive media systems in general have been increasing our pattern recognition abilities. Whatever the arguments over IQ, it is a measure of pattern recognition, and it is rising. “The theory of evolution is just that: a theory. No one really knows for sure how it works”. You could say the same about gravity. Actually, scratch that. Evolution is much better understood then gravity. Imagine if we were gorillas!It darkens the skin from the inside-out is headed towards clinical trials to treat actual skin diseases, thousands of people are already experimenting with the drug, thanks to the pharmacy we call the Internet. Melting Arctic Prompts Calls for ‘National Park’ on Ice The chunks of the arctic that will retain ice in a warming climate need to be preserved for wildlife, say some scientists. Autonomous Robots Invade Retail Warehouses I, for one, welcome our new Gap.com robot overlords. Top 5 Most Extreme Exoplanets While astronomers haven’t found a exoplanetary fit for life yet, they have found plenty that are too big, too hot, too cold, too dense, too close to their star, or too distant.