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It's funny. Laugh. Science

Pants Were Optional, 100,000 Years Ago 68

Posted by timothy from the lousy-research-methods dept.
RobertB-DC writes "German scientists have used differences in the DNA of lice to determine when humans started wearing clothes. It seems lice are highly specialized -- head lice lay their eggs only on hair, while body lice hide theirs in the folds of clothing. Using the differences in the two species' DNA and a "standard" mutation rate, the scientists determined when clothing-specific lice (and by extention, clothes) came into existence. No comment, though, from Calvin Klein."
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Pants Were Optional, 100,000 Years Ago More

Pants Were Optional, 100,000 Years Ago

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  • Sadly... (Score:5, Funny)

    by danratherfan ( 624592 ) on Tuesday August 19, 2003 @10:50PM (#6740536) Journal
    washing clothes wasn't invented until 5,000 years ago.

  • Huh? (Score:3, Funny)

    by BladeMelbourne ( 518866 ) on Tuesday August 19, 2003 @10:51PM (#6740541)
    Pants are still optional, depending upon where you like to [let it] hang out.


  • Determine the first "casual Friday" and follow its migration around the country.

  • We naturists... (Score:3, Informative)

    by n1ywb ( 555767 ) on Tuesday August 19, 2003 @11:00PM (#6740595) Homepage Journal
    We naturists [naturistlife.com] have known for some time that pantsless is the way to go. No news to us.
  • right here & right now, baby...

  • furs? (Score:2)

    by zenyu ( 248067 )

    If specialization is as important as they state this only indicates that sewn cotton clothes with seams originated in the last 200,000 years. It doesn't tell us when Lama/Wool sweaters were first worn or when furs were first worn or even when we started wrapping ourselves in decorative blankets...

    It seems like all of those would serve the same sexual and political purposes as tailored slacks.

    "Dude, she's wrapped in a purple blanket! Choice!" -- da Caveman speaks...

    "i c u'r wearing a lion skin, let's make
    • I doubt sewn cotton clothes have been around anywhere near that long (200,000 years), as that requires both a spinning wheel and a loom of some sort. I suspect we were wearing hides up until probably 10,000 years ago, if not later. Seems doubtful that writing and language would develop that far behind the ability to make cotton fabric.

  • Hrm... (Score:4, Funny)

    by asdfx ( 446164 ) on Wednesday August 20, 2003 @12:01AM (#6740894) Homepage
    They're not optional now? That probably explains a few things...

  • This... (Score:5, Funny)

    by FreeMath ( 230584 ) on Wednesday August 20, 2003 @12:03AM (#6740900) Homepage Journal
    comes as no supprise to CmdrTaco, as he has long known that:

    Pants are optional, but recommended for you.
  • The logic in the link is that since we can prove lice that live on clothes evolved 100,000 ago, then clothing must have emerged about 100,000 ago.

    Wrong - evolution is _slow_. It could as easily have taken a million years for the lice to make the jump from hair to cloth. In the intervening period, man would have had clothing without clothing-specific lice. So the 100,000 guessat at in the article cannot be right.

    • I think they overstate their case but it is not entirely flawed.

      Evolution may be slow but it can express itself in a population very quickly. An adaptation that provides no specific advantage may spread through an isolated group (keep in mind this is happening in a huge number of groups). Then at some point in time it does become an advantage so the population of this group explodes as it expands into the newly created niche.

      The fossil record provides strong evidence that changes in populations occur

    • Re:Atricle has flawed logic IMO (Score:4, Informative)

      by Lars Arvestad ( 5049 ) on Wednesday August 20, 2003 @04:04AM (#6741918) Homepage Journal
      This is what the actual paper in Current Biology by Kittler et al says:
      A critical assumption is that the origin of body lice reflects the origin of clothing; it is possible that clothing existed for some time before lice exploited this new ecological niche, in which case the origin of clothing could be much more ancient than the origin of body lice. While we cannot exclude this possibility, the colonization of a new ecological niche usually occurs rapidly after it becomes available. Since modern humans and archaic humans such as Neandertals diverged about 250,000-500,000 years ago, in order to associate clothing with archaic humans, clothing would have had to exist for hundreds of thousands of years before the origin of body lice, which seems improbable. Moreover, archaeological evidence does not contradict an association of clothing specifically with modern humans, as the only tools that can be definitely associated with clothing, such as needles, are only about 40,000 years old.
      So they certainly address the issue. These guys are not naive---The last author, Mark Stoneking, is a very experienced and respected investigator.

      Their dating is actually 72000 +- 42000 years btw.

    • > The logic in the link is that since we can prove lice that live on clothes evolved 100,000 ago, then clothing must have emerged about 100,000 ago.

      > Wrong - evolution is _slow_. It could as easily have taken a million years for the lice to make the jump from hair to cloth. In the intervening period, man would have had clothing without clothing-specific lice. So the 100,000 guessat at in the article cannot be right.

      Antibiotic resistance happens pretty fast. We've only had antibiotics for about ha

      • antibiotic resistance need not come from mutation. If we kill off all the non-resistant bacteria, then only the resistant are left to propagate, but they haven't developed any new DNA or anything. No evolution, no mutations, so, yes, it happens very quickly. (As soon as you kill off all the non-resistant bacteria.)

        • > antibiotic resistance need not come from mutation. If we kill off all the non-resistant bacteria, then only the resistant are left to propagate, but they haven't developed any new DNA or anything. No evolution, no mutations, so, yes, it happens very quickly. (As soon as you kill off all the non-resistant bacteria.)

          Yes, but you can compare the DNA of the resistant strain to your samples of earlier strains and see whether the resistant strain is merely a subset of the old or is actually something new.

        • antibiotic resistance need not come from mutation.

          It does if you start your culture with only one bacterium. This is such an obvious experiment that surely someone has tried it at some point; does anyone happen to have any references?
    • Evolution in longer-living creatures is often slow. I don't believe lice actually live very long, therefore in a human lifespan you'd probably have many many louse lifespans.

      Wasn't this one reason some tests were done with flies? Because evolution/change in the flies would occur faster due to the more rapid birth/reproduction/death cycle?

      That, and we're talking hundreds of thousands of years... being off by a few centuries (which would be a lot of louse generations I would expect) wouldn't be a bad marg
  • Using the differences in the two species' DNA and a "standard" mutation rate, the scientists determined when clothing-specific lice (and by extention, clothes) came into existence.

    The article states that the "scientists" calculated one metronome per 30,000 years and thus concluded that body lice branched off from head lice about 72,000 years ago. What?!?!? How likely is it that mutations really occur on average without much of a deviation from the mean that regularly? For all we know, mutations occur in l
    • Not very accurate at all and the authors of the original research paper says that too. The estimate the present is actually 72000+-42000 years.

    • Re: How accurate is this really? (Score:5, Insightful)

      by Black Parrot ( 19622 ) on Wednesday August 20, 2003 @04:39AM (#6742003)


      > The article states that the "scientists" calculated one metronome per 30,000 years and thus concluded that body lice branched off from head lice about 72,000 years ago. What?!?!? How likely is it that mutations really occur on average without much of a deviation from the mean that regularly?

      You do have to be careful about that sort of thing. For example, attempts to apply the same logic to language (glottochronology [wikipedia.org]) are not generally accepted by linguists because so much of language change is driven by social factors rather than blind mechanistic processes.

      > For all we know, mutations occur in leaps and bounds. It might be very similar to those annoying studies of amortized cost in my algorithms classes. Sure, great, probability theory is great and all, but what about reality?

      I'm certainly no expert on this, but there are several things that appear to be working in favor of using mutations as a biological dating system. For one the molecular mutations that form the basis of the method do appear to be the result of blind mechanistic processes - at least if you can avoid the error of measuring parts of the genome that are subject to pressures for or against preservation or change. For another you've got the Law of Large Numbers [wikipedia.org] working in your favor, both in terms of the size of the DNA molecule and the number of generations. Unless we're missing something these factors should conspire to give us an expected value for the mutation rate and an opportunity to average it over a very large number of events (length of DNA * number of generations), allowing us to apply standard statistical methods to calculate an expected value for the number of mutations and a confidence range for it.

      Also, we live plenty long enough to measure mutation rates between generations of organisms today, including humans as well as lice and other species. It should be pretty easy to calculate an expected value of number of mutations per unit length of DNA per generation, and see how much variance there is in that number today, and compare that to what our calculations suggest for the evolutionary timescale. (I'm not familiar with the literature on the actual numbers but I know at least some of it has been done, because a few years ago I read something about the typical number of mutations observed in human babies. I'm not citing the number because I don't trust my memory on it. But the fact that they could even name a number goes far toward establishing the kind of model you need for this kind of dating.)

      A big problem for the method would be if mutation rates have changes significantly over time, e.g. due to radiation or environmental chemistry, and this kind of stuff is hard to check directly. However, science is "convergent" in the sense that we expect our various theoretical approaches to give the same answer if they are in fact correct, so the fact that this study produces a number that matches the previously established number for when our ancestors left Africa and moved into regions where clothes would be necessary, all adds up to a satisfyingly consistent model of what happened to cause all the relevant observations.

      There is of course the epistemological problem of the inability to prove anything in the empirical sciences, but since that problem is unsurmountable we more or less ignore it and take our supportable results as "true" - but not as "Truth" - so long as the explanation seems to work and converges with all our other models for what's going on in the universe. If we discover later that we did something wrong we simply have to revise our results when that time comes, but that's an unavoidable risk we have to take; the only other alternative is to throw up our hands in despair and not try to understand the world at all.

      If you want a more expert analysis of any of this you might want to post it as a question on talk.origins, which is inhabited by all manner of biologists, mathematicians, etc., who can daze you with more than you want to know about virtually any topic.

  • Oh, i see Lockheed Martin have an ad on "a small diameter bomb with pnav", could be handy for a terrorist like me.. , or against lice to stay somewhat on topic...
  • 100,000 years ago totally ruled, man.
  • If I recall correctly (I'm no historian), skirts/kilts were more popular due to the ease of fabrication back then.

    I would think that it would make sense that these types of lice could infest the nether-regions as if they were pantless.
    • Well up to about 200 years ago you have to remember that fabric was *VERY* expensive. If you were to go to the fabric store today you could find a lot of fabric for under $10/yd (and the major inustreal types pay less) but back in the day when you had to do it all by hand it may have been like $100 a yard for fabric. As such you are going to make garments to have as little waste as posible.
  • I still consider pants optional. Especially while naked.
  • Pants... Pants... Sing the praises of Pants...

    Nothing better shows my taste
    Than what I wear below my waist

    Pants... Pants... Sing the praises of Pants...

    They help me suck in my gut
    They always cover up my butt

    Pants... Pants... Sing the praises of Pants...

    Wear them and you're a cool guy
    As long as you zip up your fly

    Pants... Pants... Sing the praises of Pants...

    That's right, ladies and gentlemen. Consider the pant. You know, the Pant Association urges you to wear your pants at least three times a day. T

  • A scenario (Score:3, Insightful)

    by exp(pi*sqrt(163)) ( 613870 ) on Wednesday August 20, 2003 @05:36PM (#6748777) Journal
    Lice could have made the jump from fur to clothing many times. If the last time it happened the lice were so successful they displaced the previous species we'd only see one recently jumped species today. You really need a lot of caution with this data even if you do assume that evolution rapidly fills new niches.

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