Tim Worstall

Evolution in Action

Happily this will piss off all the right people. Natural selection in action.

THERE’S nothing like the threat of being eaten to make an animal evolve in double-quick time, a study of lizards has shown.

Twice within a year the brown arole lizard has evolved changes in
its body and behaviour to outwit a predator — confirming Charles
Darwin’s theory on natural selection.

…

Jonathan Losos, of Harvard University, said: “Long-legged lizards
fared best at first, because they could run faster. As they began
climbing trees to escape, however, short-legged individuals proved more
nimble on the branches and more likely to survive.

“These changes occurred within a single generation, showing how the effects of natural selection can play out very quickly.”

In

14 responses

  1. The Pedant-General Avatar
    The Pedant-General

    “These changes occurred within a single generation”
    By its very definition that is wrong. Natural selection is about your ability to pass on your genes to the NEXT generation because you have survived.
    Tim adds: No, it isn’t. Natural selection is about who survives a change in the environment: like the arrival of a new predator.

    Reply
  2. Mark Holland Avatar
    Mark Holland

    The predator’s a bit of a laggard though. Any news on his evolving in a bid to catch up?

    Reply
  3. John M Avatar
    John M

    The trouble is that this case just shows that certain charcteristics within a species will be selected for, but that is fairly uncontroversial. The ant-evolutionaries argue that selection cannot account for speciation. And that is a tougher argument. If a new species had evolved in response to the predator, that really would be something.

    Reply
  4. zorro Avatar
    zorro

    JohnM. Ever heard of Flu? It readily evolves most years into new strains. Do you seriously doubt evolution /is occuring/ around us all the time?

    Reply
  5. John M Avatar
    John M

    JohnM. Ever heard of Flu? It readily evolves most years into new strains. Do you seriously doubt evolution /is occuring/ around us all the time?
    A strain of a virus is a different sort of thing from a new animal species. And it is not a question of whether or not I doubt evolution is happening all around us all the time, the fact is that we have not ever observed it happening. We have not seen a new species emerge through selective pressures.

    Reply
  6. John M Avatar
    John M

    JohnM. Ever heard of Flu? It readily evolves most years into new strains. Do you seriously doubt evolution /is occuring/ around us all the time?
    A strain of a virus is a different sort of thing from a new animal species. And it is not a question of whether or not I doubt evolution is happening all around us all the time, the fact is that we have not ever observed it happening. We have not seen a new species emerge through selective pressures.

    Reply
  7. embutler Avatar
    embutler

    you are confusing natural selction with genetic change
    new species arise thru natural selection,isolation ,sexual preferences
    and it takes time
    genes get lost and/or scrambled and/or doubled…etc
    you had a wonderful demonstation in england..
    dark moths on light trunks got eaten..more light moths survived
    light moths on dark(pollutin) trunks got eaten
    now you have light trunks again and light moths are making a comeback…any genetic changes..nope

    Reply
  8. John M Avatar
    John M

    “you had a wonderful demonstation in england..
    dark moths on light trunks got eaten..more light moths survived
    light moths on dark(pollutin) trunks got eaten
    now you have light trunks again and light moths are making a comeback…any genetic changes..nope”
    The peppered moth isn’t a great example, actually, because the evidence was faked, but you are right that variations within species due to natural selection happen and can easily be observed or produced artificially. But evolutionary theory makes much bigger claims than that. It claims that new species evolve from other species. And that is something we have never observed.

    Reply
  9. Dom Avatar
    Dom

    “The peppered moth isn’t a great example, actually, because the evidence was faked”
    Actually, the evidence wasn’t faked, the well-known textbook photos were. And I wouldn’t say faked, I’d say they were, well, staged, to make a simple point even simpler — something like smoothing a curve.

    Reply
  10. Dom Avatar
    Dom

    Somebody turn the damn italics off!!!

    Reply
  11. JuliaM Avatar
    JuliaM

    OK!

    Reply
  12. JuliaM Avatar
    JuliaM

    Damn, that worked in ‘preview’ but not in ‘post’. Hmm…..

    Reply
  13. David Gillies Avatar
    David Gillies

    Oh Lordy, not tho old ‘we’ve never observed speciation’ canard. It’s been observed dozens of times. It’s been INDUCED among laboratory strains of fruit flies, for God’s sake. The usual definition of speciation is reproductive isolation. Populations have been observed splitting into reproductively isolated groups on many occasions. This is simply a fact. Allopatric speciation we know occurs, and recently there have been incidences seen of sympatric speciation. Anyone who seriously doubts the truthfulness of the neo-Darwinian synthesis is either ignorant or stupid. That we have witnessed new species emerge is an uncontroversial idea that a few moments’ perusal of Google would confirm. And that speciation has occurred, unobserved, in the past, is so firmly accepted a notion as to make any denial of it look witless. Cladistics, morphology, genetic assays—these all confirm speciation to an extent rare in science. This is not an article of faith. Evolutionary theory needs no apologia or special pleading. It’s about as well-attested as any scientific theory we have. In terms of its bolstering evidence, the theory bests almost all others. Why doesn’t, say, string theory arouse as much passion among laymen? That’s a vastly more speculative and ill-formed area of scientific endeavour. Any scientist worth his salt would relish a genuine controversy in evolutionary theory. That’s what scientists do—challenge orthodoxy. It’s how science proceeds. If there were really any serious challenges to the theory, people would be shouting it from the rooftops.

    Reply
  14. Dom Avatar
    Dom

    “Evolutionary theory needs no apologia or special pleading. It’s about as well-attested as any scientific theory we have.” Exactly. But in fairness, what the commenter meant by “speciation” is something more dramatic than “reproductive isolation”. He meant the evolution of man from ape. (That this has not been observed doesn’t matter to me. But I think it does to the commenter.)

    Reply

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