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Science

Recent Human Evolution May Have Been Driven By Self-Selection 448

Slur writes "The New York Times reports an insightful theory of Human evolution that gives credit for our accelerated evolution to the evolving brain. By virtue of our aesthetic and utilitarian preferences we ourselves have been responsible for molding the present human form and consciousness. Applied to other species we call it 'artificial selection,' but the new theory implies we did it all quite naturally, unconsciously, and that the exponential evolutionary acceleration we have achieved as a species in recent time is just what you'd expect. It also suggests that the current lull in our physical evolution is by 'choice' as well."
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Recent Human Evolution May Have Been Driven By Self-Selection

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  • by Anonymous Coward on Thursday December 13, 2007 @05:38PM (#21688784)
    It doesn't matter if we evolve, because we change the environment around us as opposed to adapting to it. Therefore evolution has been irrelevant as a factor of survival since humans learned to use tools.
  • Broken circularity (Score:5, Insightful)

    by Empiric ( 675968 ) on Thursday December 13, 2007 @05:44PM (#21688886)
    So, we're talking about teleological choices, made by teleological beings, driving a non-teleological process?
  • by __aaclcg7560 ( 824291 ) on Thursday December 13, 2007 @05:44PM (#21688896)
    Yeah, dumb luck usually works most of the time.
  • by Toonol ( 1057698 ) on Thursday December 13, 2007 @05:48PM (#21688952)
    Unless we are evolving to get better at using tools.
  • by plague3106 ( 71849 ) on Thursday December 13, 2007 @05:56PM (#21689136)
    who comes from that classic heartless eugenics-oriented pov that we as a species are getting physically unfit as we allow the autistic, the downs symdrome, the epileptic, etc., to survive and breed. in classic trollish fashion, he insisted the cavemen had it right when they just left the old, infirm, etc. to die outside in the snow

    You do realize this is how evolution works right? That's EXACTLY what every other complex organism does.

    Honestly, what is the benefit to our species as a whole to continue to create genetically wrong humans, that can't survive without depending on society the rest of their life? Other animals leave the unfittest behind because otherwise the ENTIRE group will perish. Empathy in any other species would spell the end of that species.
  • Thank you (Score:3, Insightful)

    by Chuck Chunder ( 21021 ) on Thursday December 13, 2007 @06:16PM (#21689486) Journal
    For demonstrating so succinctly the wilful ignorance that many religionists have with regard to evolution.
    You could have wasted our time but all it took was a 7 word comment and a three word sig. Ten words.
  • by Raffaello ( 230287 ) on Thursday December 13, 2007 @06:17PM (#21689506)
    This is an oversimplified view of how evolution works. In fact, it's so oversimplified as to be grossly misleading.

    Evolution works by *differential* reproductive success. This does not require in any way that we leave the "unfit" out in the snow. Their own genetic disadvantages will see to it that they simply leave fewer offspring.

    By intervening directly (the "leave them out in the snow" school) you run the very significant risk that you mistakenly identify as "unfit" individuals whose genomes contain significant survival advantages that would otherwise be passed on in the gene pool.

    IOW, not being omniscient, people are likely to identify as "unfit" individuals who they simply don't like, feel threatened by, etc., and prevent from reproducing people who are, in fact, carriers of genes with significant survival value.

    It's called "natural selection" for a reason: the inevitable expression of each individual's genome will of necessity result in some individuals leaving more offspring than others. These individuals are, *by definition* the fittest. No need to intervene - it's already taken care of.

    Note that in artificial selection, breeders can only select for heritable traits that they observe. In the process they often end up with breeds that carry significant deleterious traits because the breeders were not aware that they were inadvertently selecting for these as well.

    It all comes down to humility about our lack of omniscience. Anything short of a complete understanding of all the complexity of the human genome, epigenetics, and how these interact with various past, present and yes, even future environments, will lead to the unintended, but potentially disastrous reduction of variation and loss of genes of significant fitness.

    The system (natural selection) works well precisely because there is nothing driving it except the objective reality of navigating the myriad vagaries of life successfully to the goal (from evolution's standpoint) of reproducing. Let's not pretend that we understand all of it fully and interfere with it.
  • by 2nd Post! ( 213333 ) <gundbear@pacbe l l .net> on Thursday December 13, 2007 @06:18PM (#21689514) Homepage
    What is the benefit to our species as a whole to create genetically wrong humans?

    Excuse me?

    How about the geniuses with perfectly sound minds but unsound bodies? Like Stephen Hawking?

    Are you saying the only value humans have is their ability to survive independently of each other? That children who cannot hunt down a buffalo without the help of a parent, or even a peer, is useless? Yet what is cooperation to achieve things greater than an individual (the space shuttle, the pyramids, the aqueducts of Rome, raising a single child) except "depending on society for the rest of their life"?

    Perfectly FIT people depend on society their whole lives! Can you generate your own electricity, recycle your own trash, smelt your own steel, craft your own furniture, etc?

    So even genetically wrong people can offer things, such as their minds, their voices, their arts, etc, to humanity. On top of that, their survival broadens our genepool; what if the AIDs resistance virus lies in a mildly autistic child? Or the resistance to the next bird flu pandemic lies in a mildly retarded child?
  • So what if we change the environment? That doesn't stop evolution. There are always traits that will give an advantage, and those that will give a disadvantage, and there are always novel ways of combining previous traits that can lead to something new. Evolution has never been about survival, it is about passing on genes. And every organism out there changes the environment. Organisms define the environment: prey to some, predator to others, host to still others. To stop evolution in humanity, one would need to ensure that every human on the planet had exactly the same chance to pass on their genes as every other.
  • by ChromeAeonium ( 1026952 ) on Thursday December 13, 2007 @06:19PM (#21689534)
    Eugenics might work in the short run, but I doubt it would be a very bad thing in the long run. First off, by selecting such traits, you decrease the amount of genetic difference between offspring. Sure, they might all live to be 120 and be able to bench press a truck, but that won't be much consolation when a single virus kills everyone. I find the commercial banana to be a good example. Years of breeding the best fruit and healthiest plants, and it is very possible that a single disease could ravage the population because of that lead to too much genetic similarity between plants. You can also look at the cheetah population to see the long term results of a small breeding pool. You stop the 'unfit' from breeding, you're going to have one hell of a mess on your hands in a few generations. Personally, I'll take cancer and obesity over crippling birth defects and constant fear of illness.

    And besides, evolutionarly speaking, life evolves by trying new and weird things. Maybe fat and ugly is the next phase in human evolution. Do you know? Do you think anyone knows enough to direct human evolution? Then shut up.

    Oh, and there's the fact that you'd have to be one immoral bastard to decide that certain groups arn't allowed to have kids.
  • Re:Physical lull. (Score:4, Insightful)

    by bkr1_2k ( 237627 ) on Thursday December 13, 2007 @06:23PM (#21689604)
    Yeah, but who's going to mate with you now in order to ensure that? I'm guessing no one.
  • by Andrew Kismet ( 955764 ) on Thursday December 13, 2007 @06:24PM (#21689616)
    Biological evolution has ceased, according to yourself.
    However, mental and social evolution continues.
    Any further biological evolution of humans will only be on the "resistance to disease" level, and that which we do ourselves. Transhumanists are gonna love this news. Augmentation's always getting closer.
  • by Dhar ( 19056 ) on Thursday December 13, 2007 @06:25PM (#21689618) Homepage
    Don't confuse evolution with speciation.
  • by EmbeddedJanitor ( 597831 ) on Thursday December 13, 2007 @06:35PM (#21689780)
    Natural selection tries to weed out a huge % of the population, but medical science overrides it.

    Nature determines that weak and premature infants should die, yet they are kept alive and become adults. Nature determines that some adults should not be breeding, yet fertility drugs override this. Nature determines that various people should die by heart failure etc, but drugs keep them alive.

    Sure, these are all good from the emotional point of view of keeping people alive and making childless couples happy etc, but does it really help the human gene pool? Perhaps Mother Nature had a good reason to kill off a weak child or prevent that infertile couple from breeding. The long term impacts can only be known in a few generations.

  • Re:Eugenics (Score:4, Insightful)

    by SatanicPuppy ( 611928 ) * <SatanicpuppyNO@SPAMgmail.com> on Thursday December 13, 2007 @06:57PM (#21690082) Journal
    I'd call into question whether or not it works...Far as I know we've had no solid scientific trials among human-type animals.

    The root of the problem is that someone really has to know what traits are going to be best for the entire species, otherwise they're just extinguishing genetic diversity in pursuit of a goal which may turn out to be a stupid goal.

    There is an economic equivalent to eugenics; communism. The idea there is that the government is smart enough to be able to decide what everyone should be producing and what everything should cost. It's an utter disaster...Whenever you add free market reforms to a communist country you can watch their economies go nuts.

    The reason for this is simple. Having a few thousand people making decisions about what will benefit millions doesn't work as well as all those millions making those decisions about what will benefit themselves...No matter how smart or well informed that minority is, they can't be reliably informed about the minutiae of every member of the majorities' positive and negative qualities.

    What is dating but a process by which you weed out people whom you believe to be inferior to share your genes with? It's a long term research project carried out by literally billions of people, and you really think that a few people with an idea of what the "perfect" person will be like can do it better? That's some serious arrogance.
  • by Lord Ender ( 156273 ) on Thursday December 13, 2007 @07:01PM (#21690166) Homepage
    Altruistic tendency is considered "fit" when dealing with social animals (anything with packs, herds, or tribes). Empathy helps with altruism. It means we make personal sacrifices in order to help the group as a whole (because the group shares many common genes with us).

    Empathy so extreme that it hurts society, such as allocating resources away from growing our numbers to extending the lifespans of the severely disabled is NOT evolutionary altruistic.
  • Actually...No. (Score:4, Insightful)

    by SatanicPuppy ( 611928 ) * <SatanicpuppyNO@SPAMgmail.com> on Thursday December 13, 2007 @07:05PM (#21690240) Journal
    If you really think evolution is limited to gross physical changes, you've got a really poor understanding. We may not be evolving hooves or fur, but resistance to diseases, resistance to certain types of chemicals that are now more abundant in our environments, ability to withstand a lifestyle that would have been utterly alien to our cave-dwelling ancestors...All these things represent tremendous environmental pressures.

    Couple that with a vastly increased species population, representing a staggering amount of genetic diversity, I have no problem believing that we're still evolving, and indeed, that the rate may very well have increased.
  • by Toonol ( 1057698 ) on Thursday December 13, 2007 @07:24PM (#21690504)
    It's not that one-sided. For example, we've invented cars, and now we drive fast. People with a poor ability to process visual information quickly, project trajectories, and convert that to a decision to turn/brake are going to be selected against. That's just an innate consequence of having developing an automobile.

    We are changed our tools, while our tools are changing us. Granted, our tools are changing at a much faster rate...
  • Re:sigh (Score:3, Insightful)

    by merreborn ( 853723 ) on Thursday December 13, 2007 @07:43PM (#21690798) Journal

    Your inference that there has been intellectual evolution is rather disturbing, one look at US politics should tell you that not much intelligence evolution has really occurred


    The fact that college students spend years studying the scientific discoveries of men who have been dead for centuries is something of a testament to that. Much of what we know about math, physics, chemistry, and philosophy was explained by the likes of Euler, Newton, and Descartes.

    Not to say we haven't come a long way since then, but stop and think about that -- much of what your average highschool graduate has learned has been public knowledge for centuries.
  • by 2nd Post! ( 213333 ) <gundbear@pacbe l l .net> on Thursday December 13, 2007 @08:19PM (#21691272) Homepage
    It IS evolutionary beneficial, however, if it means it broadens the diversity of our genepool.

    What if the severely disabled (with the ability and the inclination to reproduce) have the genes for AIDs resistance? Bird-flu resistance?

    You don't know a priori which genes are important until a selective pressure makes them important. Early optimization is a bad choice in that case. It is a question of degree; how disabled is too disabled?
  • by Anonymous Coward on Thursday December 13, 2007 @08:35PM (#21691456)
    People, get a grip on yourselves! The human race is not "speeding up its evolution" - there's no known way for a species to do that. Instead, the human race, having removed all driving forces of evolution, has stagnated to a dead standstill and half of it is now slipping back to the ape stage. The vast discrepancy is not attributable to the higher half advancing, but the lower half falling back.

    And don't get too smug. Soon it will be all the humans slipping back. I've seen this coming for 20 years. Nature has no use for exceptional brains, beyond knowing how to feed yourself and stay alive long enough to ejaculate or spew out a kid, nature doesn't give a damn.

    Yes, it's an awful truth, but face it anyway.
  • by Cairnarvon ( 901868 ) on Thursday December 13, 2007 @09:21PM (#21691920) Homepage
    Good to see the type of ignorance that led to the eugenics movement is still alive and well in the world today.

    http://en.wikipedia.org/wiki/Naturalistic_fallacy [wikipedia.org]
  • by ucblockhead ( 63650 ) on Thursday December 13, 2007 @09:27PM (#21691992) Homepage Journal

    Girls like tall guys, so we'll get taller.


    Thing is, there are equal numbers for the sexes. Girls like tall guys, so attractive girls will get the tall ones. Unattractive ones will get the short ones. Since there are as many women as men, everyone finds someone to mate with even if they aren't ideal. Since everyone breeds successfully, we *won't* get taller, though you might see a flatting of the bell curve of men think tall women are attractive. There is no "survival of the fittest" as everyone, tall or otherwise, survives to breed.

    As long as humans a serial monogamists, this is the way it would go. For animals that are polygamous, it would happen as you say.
  • by gwait ( 179005 ) on Thursday December 13, 2007 @09:33PM (#21692056)
    Odd how people think humans have stopped evolving.

    A huge evolution experiment is sadly taking place in Africa, with the Aids epidemic.

    The flu pandemic of 1918 was a significant evolutionary event, estimated deaths of up to 40 million people worldwide. http://virus.stanford.edu/uda/ [stanford.edu]

    The next big flu pandemic will also cause evolutionary change. Read "Collapse" by Jared Diamond for many examples of pandemics in recent history - including the 95% wipeout of North and South American natives who had never been previously exposed to the many diseases brought over from Europe and Asia.

    If we end up with something like Aids or SARS that spreads from a simple sneeze, then we just might find that natural selection favours a society completely isolated from air travel.

    The individual cases you mention in a rich western society are just a noise floor in the bigger picture.

  • by Anonymous Coward on Thursday December 13, 2007 @10:03PM (#21692362)
    "Since there are as many women as men, everyone finds someone to mate with even if they aren't ideal"

    My 27 years of life without sex or even a partner seems to show a flaw in your model. And I'm above average height and attractiveness. Granted, I've got a lot of life left to go, but the safe bet would be on things not changing for me any time soon--if ever. I suppose I'm also just one case, and statistically insignificant, but you're using words like "everyone" and since I'm part of everyone...
  • Re:Eugenics (Score:4, Insightful)

    by servognome ( 738846 ) on Thursday December 13, 2007 @10:09PM (#21692430)

    Why would breeding for intelligence at the expense of resilience be desirable?
    Because historically we've seen intelligence can compensate for resilience better than resilience can compensate for intelligence.
  • by Baumi ( 148744 ) on Friday December 14, 2007 @12:14AM (#21693506) Homepage

    "Since there are as many women as men, everyone finds someone to mate with even if they aren't ideal"

    My 27 years of life without sex or even a partner seems to show a flaw in your model. [...] I suppose I'm also just one case, and statistically insignificant, but you're using words like "everyone" and since I'm part of everyone...
    Trust me, you're not alone with this one. IMHO, the number of "unwilling" singles has increased quite a bit in the past few decades.

    There are several social factors at work, here:

    1) Less financial pressure to look for a mate, since people can afford living without a family. You don't necessarily need a partner or children to care for you when you're old. (Although it would probably be nice to have someone who'd visit you...) Also, women do not depend on marriage to survive anymore.

    2) Less social pressure to seek a mate, since it's become socially acceptable to be single for both men and women.

    Both #1 and #2 contribute to a shrinking market of potential mates, since people have less reason to look for one in the first place, and even if they do they'll be more discriminating, since their survival doesn't depend on finding a partner.

    3) Less opportunities to meet people. Imagine the world before TV: If you didn't want books or crafts to be your only source of entertainment in your spare time, you had to go outside and meet living, breathing people. With TV, your home offers more entertainment than any theatre, but without the fellow audience. (Actually, the internet may lessen this effect, since it's obviously a very social medium, although without actual physical presence.)

    4) More ways to spend your time alone. This is closely related to #3: With more solo activities available, shy people will have more ways to avoid human contact, thus they'll have less opportunities to develop their social skills and overcome their shyness. Again, social contacts via the internet might counter that effect to a certain extent.

    With relationships being much more optional than ever before, the natural advantage of sociable people is amplified, and quieter, more reclusive people are less likely to find a mate. However IMHO, this state would need to stay like that for quite awhile in order to have any significant evulutionary impact, especially since all of this only applies to societys that are roughly similar to our western culture, of course. I have no idea how things work in other cultural regions.
  • by misanthrope101 ( 253915 ) on Friday December 14, 2007 @02:05AM (#21694224)
    I'm always perplexed when people blame eugenics on evolution. It's not as if no one had thought to wipe out a particular group of people before Darwin came along. Obviously if you kill all the blind people, there won't be blind people. If you kill the Jews, there won't be Jews.

    After Darwin wrote The Origin of Species, people just took what they were doing before and rephrased it as pseudoscience. Now you have Hovind and other creationists saying that the eugenics crowd were motivated by evolutionary theory. The movement had much less to do with evolution than it did Mendelian genetics--does that mean genetics is a fraud? Does the idea of inheritance lead inexorably to Nazi eugenics experiments?

    Or can we safely say that people have always been tempted, here and there, to wipe out anyone whose existence they found distasteful, and they'll tack their bigotry onto any pseudo-science they can just to lend their efforts a patina of legitimacy?

  • Re:Eugenics (Score:4, Insightful)

    by Iron Condor ( 964856 ) on Friday December 14, 2007 @02:53AM (#21694520)

    [...] conceivably we could be living much, much longer.

    Longevity is an evolutionary dead end.

    Physical immortality is easy. Bacteria figured it out. That's why they're still bacteria.

    If you keep hardware around for too long, it'll be yesterdays hardware very quickly. And thus be obsoleted by tomorrows hardware.

    Planned obsolescence of hardware keeps the means of production busy and allows for constant incremental improvements to the layout of the product.

  • Re:Eugenics (Score:2, Insightful)

    by mastershake_phd ( 1050150 ) on Friday December 14, 2007 @04:11AM (#21694950) Homepage
    Longevity is an evolutionary dead end.

    True, but I wouldn't mind being immortal and obsolete.
  • by jandersen ( 462034 ) on Friday December 14, 2007 @09:10AM (#21696280)
    So, yeah, let's instead believe bogus shiny-happy fairy-tales where surely the biggest advantage was being sexy

    Hmm, something seems to have touched a nerve there. So, you don't like the thought about being nice as a selective force? No problem.

    Your reasoning isn't entirely wrong; but then again it isn't entirely true either. You seem to want to make evolution something that only favours violence and selfishness, which is a rather one-sided view of the world. I haven't read this particular article, but I am familiar with this topic - it isn't as if this is an entirely new idea.

    What is evolution really, when you think about it? One component is the fact that in each generation of organisms, some will survive and have descendants and some won't. It is worth remembering that you don't have to be particularly 'fit' in any way in order to produce desendants, you may just be lucky. The thing about 'fitness' only comes in when you look at it statistically - over time, and over a large population, it makes sense to say that the ones that kept surviving and reproducing had traits that made them more 'fit for survival'. This also means is that at any given point in time there is likely to be a proportion of traits in the population that are not advantageous, just to make that point clear.

    Another factor that is worth keeping in mind is that the environment is not something seperate from the population. In the case of human evolution this becomes especially important as our numbers grow; it is not surprising to see that genes that influence our social abilities seem to have evolved rapidly since we began to live in larger communities than the typical family groups we see with other primates. Another area where our sheer force in numbers has been important is in diseases; the more people and the close they live together, the more they will contaminate their environment and the more they will pass on infections etc, so we are under a large pressure when it comes to evolving resistence against infections.

    The examples you mention, on the other hand, don't seem to make too much sense. Humans are apes; our great advantage has been adaptability; our teeth and gut are general purpose, we are able to both walk and climb, and we have learned to work together - and it is that cooperative ability that has been our greatest asset, and it is probably also the single greatest factor contributing to the evolution of our intelligence. It has also made us the most efficient hunters on the planet - quite well done for a species that is not a predator.

    As for what you call 'bogus shiny-happy fairy-tales' - I assume you mean the idea that things like beauty and altruism play a role in evolution. Well, I'm sorry to upset your view on the world, but they do. Altruism is still one of the things we don't entirely understand from an evolutionary point of view, but we can see it happen, even amongst chimpanzees; ie. it is a FACT. Beauty, on the other hand is not difficult to understand - beautiful people are people who look healthy (ie. likelier to produce good offspring), whose facial expressions are mostly kind (probably better at bringing up succesful offspring) etc etc. Our ide of beauty is a result of evolution and therefore important in evolution. The same goes for our morals - our moral rules are the ones that have been valuable for our survival as species.

    You refer to some historical facts or factoids about the Romans etc. However, our written history doesn't stretch much more than about 5000 years, and large scale evolution doesn't happen quite as fast as that, which tends to invalidate your arguments. You may not like the idea that physical beauty is important, so you try paint an ugly picture of mankind; yes, even an ugly man or woman can have sex and thus offspring, but looks are after all only one factor in this - an ugly person may have other traits that make him/her very attractive, such as a caring personality, or high social intelligence. But physical beauty is an important factor f
  • Re:Eugenics (Score:3, Insightful)

    by moeinvt ( 851793 ) on Friday December 14, 2007 @09:47AM (#21696552)
    "Hitler uses the State to enforce survival of the fittest, Libertarians essentially put the burden on the Market . . ."

    Hitler used the state to promote his own personal theories of eugenics. That's "arbitrary" selection, not "natural" selection.

    "Libertarians . . . prefer to blur the distinction between Nazism and Communism."

    If that's true, I think the primary reason would be that both of those systems are fundamentally based on the supreme power of the state and(typically brutal) suppression of the individual. The core belief of Libertarianism is limiting the power of the state and promoting the freedom of the individual.

    "the Commies were despised by the Nazis exactly because of the refusal to embrace survival of the fittest"

    That's completely ridiculous. You're suggesting that Hitler attacked Russia because Communism didn't include an appropriate amount of social Darwinism? The fact is that Hitler, again based on his PERSONAL and ARBITRARY theories of genetic superiority, viewed the Slavs as an inferior people. He planned on military conquest and large scale ethnic cleansing in order to create a larger Germany populated by his "master race". That's not "Darwinistic" in any sense of the word.

    If you want to do a hatchet job on Libertarians, try something a little less convoluted than Libertarians==Nazis and Atlas_Shrugged==Mein_Kampf.

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