Slashdot Mirror

← Back to Stories (view on slashdot.org)

Walking Before Flying

Posted by michael on from the all-that-is-old-is-new-again dept.

An anonymous reader writes "BYU biostaticians report in Nature their genetic analysis of the insect, known as the 'walking stick', which apparently gives a contrapuntal example of reversible evolution. Called Dollo's Law, the principle holds that the same evolutionary pathway can never be backtracked, because of random mutations. But this insect class first had wings, lost them, then got them back again. So what's next for some humans: a happy return to dragging their knuckles?"

4 of 32 comments (clear)

  1. rapping knuckles... by KDan · · Score: 4, Insightful

    Unlikely. The genetic difference between an insect leg and insect wing (according to these articles, see Google News for a lot more sources that came out with this days ago) is very slight, the result of a single set of genes that switch between a leg and a wing. The difference between hairy quadruped apes and intelligent biped humans is a bit more pronounced... and there's no evolutionary pressure to make us devolve back to being quadrupeds (apart from that coming from the direction of good ole' Dubya).

    Daniel

    --
    Carpe Diem
    1. Re:rapping knuckles... by KDan · · Score: 4, Interesting

      That was part of one of the articles I read about this: They said that the same genes control whether wings or legs are well-formed, so when the wing is switched off, the genes in it are still protected from too much mutation until the wings are switched on again.

      Then again, I'm by far no expert on the subject...

      Here it is: http://www.newscientist.com/news/news.jsp?id=ns999 93269.

      Researchers assumed wings could not come back once lost as the genes needed to create them would mutate beyond repair once the wings disappeared. But Whiting says there is evidence from the fruit fly Drosophila that the same genes contain instructions for forming wings and legs.

      If the same were true for stick insects, there would be an evolutionary pressure to stop wing genes from mutating, even in the insects that did not have wings. Those genes could then be turned back on in the future.

      Daniel

      --
      Carpe Diem
  2. So maybe now... by phagstrom · · Score: 4, Funny

    we can learn the answer to the puzzle:

    if a fly couldn't fly, would we call it a 'walk'?

  3. Laws of probability by xayide · · Score: 4, Insightful
    From the article:
    Dollo's Law ... is also known as the Law of Irreversible Evolution--which basically states that organisms cannot re-evolve along lost pathways, but must find alternative routes (because the same fortuitous train of mutational events, being totally random, will never repeat).
    I was not familiar with Dollo's Law before reading this story, and I may be misunderstanding some nuance or other... However, if mutations are truly random, isn't it necessary that they at least have the possibility to recreate a lost pathway, no matter how complex?