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Science

Humans Evolving 100 Times Faster Than Ever 584

Posted by kdawson
from the or-maybe-we're-just-getting-more-intelligently-designed dept.
John Hawks writes "A new genomics study in PNAS shows that humans have been evolving new adaptive genes during the past 10,000 years much faster than ever before. The study says that evolution has sped up because of population growth, making people adapt faster to new diseases, new diets, and social changes like cities. Oh, and I'm the lead author. I've been reading Slashdot for a long time, and let me just say that our study doesn't necessarily apply to trolls."
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Humans Evolving 100 Times Faster Than Ever

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  • Re:Not anymore (Score:5, Informative)

    by Rezazur (677119) on Tuesday December 11, 2007 @06:27AM (#21653691)
    I think you meant sickle cell anaemia where defective red blood cells are less prone to malaria infection.
  • by hansg (264039) <hans.gunnarssonNO@SPAMgmail.com> on Tuesday December 11, 2007 @06:34AM (#21653723)

    If the lead author on the study submitted the summary - why didn't he link to a proper paper rather than the press release junk?
    Maybe because it's not a press release, but a news article from Reuters? And if you bothered to RTFA (yes, i know, I'm new here) it says that the study is published in Proceedings of the National Academy of Sciences [wikipedia.org], which is a pretty important paper.

    Since they peer-review their articles, I would imagine that other experts thought 270 people ought to be good enough for everyone...

    /Hans

  • by The Grassy Knoll (112931) on Tuesday December 11, 2007 @07:48AM (#21654181) Homepage
    It's not "faster", it's "more quickly", as it's a comparative adverb...
  • by John Hawks (624818) on Tuesday December 11, 2007 @08:21AM (#21654435)
    The rate of mutations per genome has not changed, as far as we can tell. What is happening is that the overall larger number of people has generated more potential adaptive mutations, and these have been captured by selection. As a result, the neutral genetic changes in the population have slowed -- these being inversely proportional to population size. The very small fraction of mutations that are adaptive have caused rapid change by selection. Great question, I'll put it in the FAQ.
  • by prandal (87280) on Tuesday December 11, 2007 @08:21AM (#21654437)
    The PNAS (http://www.pnas.org) are notoriously slow at getting new papers onto the web. It'll be there within a week or so.
  • Re:Not anymore (Score:2, Informative)

    by macintyred (988926) on Tuesday December 11, 2007 @08:29AM (#21654505) Homepage
    Evolution requires TWO steps.

    The first step is to diversify the genome, which your statement points out correctly is happening at an increasing rate.

    However, the second step is culling. That's where the "Survival of the Fittest" part comes in.

    You need BOTH to evolve.
  • Re:Bad Science (Score:5, Informative)

    by John Hawks (624818) on Tuesday December 11, 2007 @08:34AM (#21654541)
    Good comment.

    Here's the answer: natural selection takes initially rare mutations and magnifies them to large numbers, spreading them to most of the population rapidly. Our survey was looking at things between 20 and 80 percent frequency in living populations. That means that the average person has around half the new selected mutations, even though each mutation is very recent. As a result, genetically today's people really are radically different than the average person living 5,000 years ago -- it's within the last 5000 years we are seeing the most rapid change in frequency of these new alleles.

    This rapid evolutionary change has also been skeletal -- bodies really have changed during this time period. But the skeletal changes are just the tip of the iceberg -- most of the changes are metabolic, or pathogen-host interaction, or brain development -- things we will never see from the archaeological record.
  • by John Hawks (624818) on Tuesday December 11, 2007 @08:40AM (#21654609)
    In terms of number of selected variants, the three populations in the HapMap are quite similar -- each has around 3000 new selected variants by our measures. Few of these are shared, because these recent things haven't had time to spread. Of the things that aren't shared, some of them probably have parallel phenotypic effects.

    For example, skin pigmentation genes causing lighter skin in Europeans are largely different from those in East Asians, even though they have the same general effect. Still, some specific effects, like hair pigmentation, may be quite different.

    Other genes respond to selection pressures that have historically been very different. Malaria is a huge source of selection in African populations historically, but it was much less important in Europeans, for example.

    As far as behavioral variations, the fact is that we don't know what most genetic changes may do. So we certainly can't say that some populations have undergone more or less behavioral change than others. Most of these changes are genetically very simple, so we're not looking at any kind of radically new changes in phenotype -- no growing antlers. The same would be true of any kind of behavioral changes under selection.
  • by John Hawks (624818) on Tuesday December 11, 2007 @08:56AM (#21654763)
    The number of people sampled is more relevant when looking for smaller and smaller genetic changes -- things that presently are at very low frequency. In such cases we will miss rare things -- just like, if we sampled 270 Americans today, we would be pretty unlikely to find an NBA player in our sample, for instance. So that undersamples diversity.

    But we aren't looking at very rare things, we're looking at the most common ones -- things between 20 and 80 percent today. In this case, it's like measuring the mean -- if we measure 270 Americans, they are unlikely to be very far from the average height. Just in the same way, these people are unlikely to present unusual evidence of selection on very common alleles.

    Of course, we must keep in mind the limits -- if we identify selected things in these few populations, we are not seeing many things that may exist in other populations.
  • by Anonymous Coward on Tuesday December 11, 2007 @09:04AM (#21654841)
    Or at least they did. Something that is fast is moving at a high speed; something that is quick has a high rate of change of speed (originally, its meaning was closer to lively, and this is the origin of the medical-religious term quickening). The proper adverbial form of fast is fast; not every adjective adds the suffix -ly when it becomes an adverb.
  • by flynt (248848) on Tuesday December 11, 2007 @09:40AM (#21655227)
    Why does every single time someone mention 'sample size', they get modded up? Look, the reason you calculate sample size for a study is so that you have an adequately powered trial to show some hypothesized effect size. If their paper is well written, they will have a small section on what they were trying to prove, and why N=270 would give them enough power to do it. All you have is one number and a gut feeling. As someone else said, what should their sample size have been then? It's completely dependent on what they were measuring. If they were able to reach statistical significance on a prespecified hypothesis, then obviously N=270 was enough!
  • Re:adaptation? (Score:2, Informative)

    by OeLeWaPpErKe (412765) on Tuesday December 11, 2007 @10:00AM (#21655483) Homepage
    fairly meditate between palestinians and israelis ?

    You do realise that the palestinians refuse to shake hands with israeli's as peace conferences, right ? WHO doesn't want peace here ? If this isn't the worst kind of racism, then what is ?

    http://www.alertnet.org/thenews/newsdesk/N26424077.htm [alertnet.org]

    There can be no peace with people who want war. And any muslim who doesn't want war is not a muslim (quran 2:219), this is to be interpreted literally (quran 3:7). Also did you know that you are "less than an animal" to any muslim (quran 8:55, again whoever disagrees with this is not a muslim, so speaks allah)
  • Re:adaptation? (Score:3, Informative)

    by OeLeWaPpErKe (412765) on Tuesday December 11, 2007 @10:39AM (#21656017) Homepage
    Did you even bother to read what I wrote? Can I say that any Christian who engages in pre-martial sex is not a Christian?

    No, you can say that a Christian who engages in pre-marital sex, damages someone by that (e.g. pregnancy and poor conditions for the child), and doesn't regret that isn't a Christian.

    Maybe any Christian that charges interest on a loan isn't a Christian.

    Again you need to take the full picture into account. If a person says "I give you X now, you give me 2X tomorrow or I kill you", certainly you can say he isn't a christian.

    And don't even get me started about all those people working on the sabbath....

    You really haven't read the bible, have you ? What does it emphasize, and what does it de-emphasize. First anyone who works in infrastructure "stuff" is exempt from this rule. So docters, road repair workers, ... all exempt. Furthermore the essence of the rule is that people are with their family, and everyone having a day off together is only to simplify this.

    So the only people you can blame are the ones working on sunday, that purposefully prevent themselves from being together with family/friends during that time. And for those, yes, you can say that their behavior is very unchristian.

    You don't know anything about any of these religions, not about Christianity and not about islam. Islam = opression (literally, the word islam means opression). Please get yourself informed. There are 6 muslim "interpretations" of islam ( 4 sunni, 2 shi'a ). ALL call for extermination of non-muslims by violent means. The shi'a ones say in addition to doing this, they should lie about it. ALL say that there can never be peace (but muslims can sign peace treaties, they just can't enforce them to their armies and/or people).

    If quotes from the quran don't define islam, then what does ?

    "fight until there isn't a single non-muslim left, and allah reigns supreme" (quran 8:39)
  • by Qwaniton (166432) on Tuesday December 11, 2007 @08:26PM (#21665669)
    What you said sounds vaguely similar to a recent Slashdot post about retroviruses. Unfortunately, all you've demonstrated is poor reading comprehension. You have no idea what you're talking about, and throwing around jargon doesn't make you make sense.

    Of course, it sounds brilliant to the Slashbot crowd.

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