Friday, March 12, 2010

Speciation is About “Happy Accidents”

A new large-scale, computational study of a hundred groups of plant and animal species finds that speciation occurs as a result of rare, lucky events. The research, which is from an evolutionary perspective, fitted genomic data to assumed evolutionary trees to evaluate the supposed speciation events that evolution requires. The research found that if evolution is true, then the speciation events occur differently than many evolutionists have expected. As reported in the journal Nature:

New species might arise as a result of single rare events, rather than through the gradual accumulation of many small changes over time, according to a study of thousands of species and their evolutionary family trees. …

“What we've shown is that speciation is about happy accidents — rare events that happen in the environment that cause a species to speciate,” says Pagel. These events could include a mountain range being thrust up or a shift in climate, he says.

The team’s findings might stir things up in the world of evolutionary biology. “It really goes against the grain because most of us have this Darwinian view of speciation,” says Pagel. “What we’re saying is that to think about natural selection as the cause of speciation is perhaps wrong.”

It is difficult to imagine a more fundamental prediction of evolution. Natural selection is practically synonymous with evolution, and this research raises yet another contradiction to this long held prediction.

21 comments:

  1. Nature article: The team’s findings might stir things up in the world of evolutionary biology. “It really goes against the grain because most of us have this Darwinian view of speciation,” says Pagel. “What we’re saying is that to think about natural selection as the cause of speciation is perhaps wrong.”

    How long, I wonder, before evolutionitsts start suspecting that speciation is itself a side-show to what they mean when they speak of "evolution" (which word, of course, they are misusing)?

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  2. Natural selection is practically synonymous with evolution, and this research raises yet another contradiction to this long held prediction.

    Well, it might or it might not, but it is hard to say since the Nature article is subscription only and the research paper is not identified in the abstract. From the comments, Professor Mark Pagel appears to be a contributor, but his papers are all subscription only. Maybe Dr. Hunter can identify the paper he is talking about so "Evolutionists" can check the primary research for themselves before commenting. Can Dr Hunter tell us if this new research credits Stephen J Gould and his punctuated equilibrium.

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  3. Complex adaptation is thought to depend on natural selection. But evolution can occur through a variety of mechanisms, some of them rather sudden, as has been known for some time. For instance, polyploidal speciation in plants or chromosomal rearrangements in animals can sometimes result in rapid reproductive isolation.

    The question then is, when you have geographically isolated populations, whether natural selection or other mechanisms are more important to establishing reproductive isolation. Even drift will result in reproductive isolation, though natural selection may increase the tempo. This study suggests that sudden changes are the most common occurrence.

    This in no way undermines the importance of natural selection to adaptation.

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  4. Alan - The abstract of the actual paper is found for free here:
    http://www.nature.com/nature/journal/v463/n7279/full/nature08630.html

    Reading it you will see the more staid tone and language of scientific writing as opposed to the "this changes everything" bluster of the Nature puff-piece summary, which reads like a university press release. These sorts of pieces have to strike interest in the lay audience, and the easiest way to do that is (over) emphasize the "cutting edge/game changing" aspects of the study. Scientists themselves are in a Malthusian struggle for limited grant money and consciously or unconsciously some of them seem to have no qualms throwing their peers under the bus. "It really goes against the grain because most of us have this Darwinian view of speciation." If I'm a pluralist evolutionary biologist I'd be asking for a straw poll. It's gold for creationists to see scientists underestimating each other, so you will far more links to press releases than to full papers.

    Also, reading the abstract, it doesn't sound like they actually tested for selection in the speciation events on a case by case basis (to do so would be a massive undertaking). Instead they produce a model of stochastic speciation based on the vagaries of history that makes the same predictions as the Red Queen model. A hybrid model is also possible - speciations might be time-invariant for stochastic reasons but natural selection might indeed be driving the bus during speciation. It would be hard to argue that the polar bear is a "drifted" brown bear, except in the sense of preferred habitat.

    Anyway, the authors have done to Darwin what Darwin had done to Paley, Cuvier, and Owen. Genetic drift imposes even fewer assumptions than natural selection and enjoys favored null status.

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  5. @ John

    Thanks but I can only read the abstract and a request for a subscription. The abstract does not suggest "yet another contradiction to this long held prediction" by any stretch of the imagination.

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  6. Hi John,

    You wrote...
    "...they produce a model of stochastic speciation based on the vagaries of history that makes the same predictions as the Red Queen model."

    Thank you for pointing out another intellectual cave for me to explore. I hadn't heard of the "Red Queen model" before so I looked it up and found this...

    http://ccl.northwestern.edu/netlogo/models/RedQueen
    "The name Red Queen comes from Lewis Carroll's "Through the Looking Glass", where the Red Queen says, "...it takes all the running you can do, to keep in the same place." In this model under the right conditions, the two species evolve as fast as they can, but neither is able to gain an advantage over the other."

    From other sources I found a common feature of this model is it often results in sudden and rapid changes to the point extinctions happen when species don't respond quickly enough.

    I presume this goes to the point you were making.

    BTW, the above link has an applet which actually runs a Red Queen Model.

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  7. Bleh, anti-science by woeful misinterpretation of press release again.

    For those of you without access, a summary:

    They start with crunching phylogenetic trees (which, as they support evolution have been vigorously disputed here. Using evidence your don't believe in to dispute a theory you don't believe in is the hallmark of this blog.)

    The data are used to test five different models of evolution.

    8% found additive small events the best model, 8% found divergence from the ancestral, 78% found rare single events.

    "Species do not so much ‘run in place’ as simply wait for the next sufficient cause of speciation to occur. Speciation is freed from the gradual tug of natural selection, there need not be an ‘arms race’ between the species and its environment, nor even any biotic effects. To the extent that this view is correct, the gradual genetic and other changes that normally accompany speciation may often be consequential to the event that promotes the reproductive isolation, rather than causal themselves."

    Mechanisms proposed: "actors apart from biotic interactions that can cause speciation include polyploidy, altered sex determination mechanisms, chromosomal rearrangements, accumulation of genetic incompatibility, sensory drive, hybridization and the many physical factors included in the metaphor of mountain range uplift."

    So- rare "big changes" might be more important that little adaptive ones in driving speciation (according to one algorithmic analysis of the data).

    Anyone not ok with that?

    Anyone see a design hypothesis in here?

    Anyone want to argue that this shows evolutionary biology is so monolithic and unchanging that it won't accept new hypothesis?

    Anyone want to argue the models that received 0% are unfalsifiable, and metaphysical?

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  8. Robert:

    ====
    Anyone see a design hypothesis in here?
    ====

    Contrastive reasoning

    ====
    Anyone want to argue that this shows evolutionary biology is so monolithic and unchanging that it won't accept new hypothesis?
    ====

    Quite the opposite, evolution is constantly patched to account for observations. "Monolithic and unchanging" ? No, definitely not.

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  9. Dr Hunter:

    ====
    Anyone see a design hypothesis in here?
    ====

    Contrastive reasoning


    Exactly. A fallacious waste of brain juice, since there's nothing to contrast with.

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  10. Dr Hunter:

    Quite the opposite, evolution is constantly patched to account for observations. "Monolithic and unchanging" ? No, definitely not.

    Welcome to science!

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  11. 'Science!' Worshipper: "Welcome to science!"

    So, are you willing to claim that this 'Science!' thingie stuff is, you know, like actually true? And, how do you know that it is?

    And, if they are not actually true, why should anyone pay attention to the quaint assertions you 'Science!' worshippers assert?

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  12. Ilion,

    If you have a constructive contribution to make, this would be a good time to start.

    Otherwise, please don't be surprised if no one pays attention to you.

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  13. I was curious to learn more about Dr Hunter's views, because I think he and I would enjoy having a friendly beer together. So I went to Conservapedia, which sadly doesn't have a biography of Dr Hunter, and did a search for "Hunter." It turned up the following in the article on Intelligent Design,

    "According to Cornelius Hunter, in his book Science's Blind Spot, the Unseen Religion of Scientific Naturalism, Descartes proposed a method of science in which "What science needed were naturalistic descriptions, even if they were not known to be true explanations. Thus, Cartesian explanations were hypothetical; Descartes argued that having a plausible yet incorrect description was better than no description at all."

    Welcome to science!

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  14. Are you really unable to grasp the point that I don't care at all about whether intellectually dishonest persons "ignore" what I say?

    You people are intellectually dishonest -- until you folf solve that, the point is *always* your dishonesty.

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  15. Ilion,

    Excellent. We are in agreement. If you can spare a moment from your busy schedule, check out the ninth commandment. You, know, it's in the Bible.

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  16. Evolution is the Borg theory of biology: it absorbs everything, even contradictory findings, into itself.

    The neoDarwinian theory of gradual change by gradual and random genetic mutation is being disproved. In faith evolutionists hold onto materialism as an explanatory myth (in the anthropological sense) of the universe and rather than admitting that Darwinism is wrong (like the ether theory of space), they rechristen materialism as Darwinism. Materialism can never be falsified, and so then neither can neoDarwinism.

    regards
    #John

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  17. Robert:

    Anyone want to argue that this shows evolutionary biology is so monolithic and unchanging that it won't accept new hypothesis?

    Dr Hunter:

    Quite the opposite, evolution is constantly patched to account for observations. "Monolithic and unchanging" ? No, definitely not.

    Is that a bad thing that a theory should be modified or abandoned as evidence accumulates. Otherwise we might still be stuck with the phlogiston theory and there would be no simple and effective antibiotic treatment for stomach ulcers.

    I get the point that you don't much like evolutionary theory. Do you have another explanation for observed reality that you could share with us?

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  18. Thought Provoker (if you're still reading):

    Hi and you're welcome. The Red Queen is an adaptationist explanation for time invariance in biological systems. Species evolve and adapt, but all their competition, prey, and predators are doing likewise, and the abiotic environment changes too, so the status quo remains. Major points to be gleaned from the abstract (and beyond) are these:

    1. Their major empirical result (time-invariant speciation) is nothing new.
    2. One prior explanation for it is the Red Queen.
    3. Authors propose a simpler model - random distribution of speciations through time due to "chance" events. (There are reasons why habitats fragment and populations disperse, etc. but there is no reason for such events to have a non-random time distribution.)
    4. Even if they don't have a specific test to distinguish the two models, the random model is simpler and is thus the null hypothesis you would have to reject before accepting the Red Queen.
    5. That speciation events are randomly distributed through time does not, however, imply that natural selection is not at work during speciation events. So unless there's a major result in the paper that's not hinted at in the abstract, this is no death knell for the importance of natural selection in producing morphologic change associated with speciation. Here I referenced the polar bear. Mitochondrial DNA shows that certain brown bear populations share more recent maternal ancestry with polar bears than with other populations of brown bears. Yet the polar bears are morphologically and ecologically distinct enough (with obvious adaptation to their new habitat and niche) that they are a unique species under the biological species concept and for a time were even placed in their own genus.
    6. The role of chance events in speciation was noted by two of the "founding fathers" of the synthesis: Sewall Wright and Ernst Mayr. No blow to Neodarwinism there, just against the Neodarwinian strawman creationists enjoy thrashing.
    7. The only camp who should be dismayed by all this is ID. Here is another example of a natural system that is memoryless (IOW mindless), like radioactive decay of (identical) unstable isotopes, wherein the stochastic decay law arises from random events. Either nobody is minding the store, or they're minding it in such a way as to make it look like nobody's minding the store.

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  19. Alan:

    "Is that a bad thing that a theory should be modified or abandoned as evidence accumulates. Otherwise we might still be stuck with the phlogiston theory and there would be no simple and effective antibiotic treatment for stomach ulcers."

    Please read Section 1 at:

    www.DarwinsPredictions.com

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  20. Hi John,

    Yes, I am still reading. Thanks for the info.

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  21. Let's see- according to evolutionists all mutations are genetic accidents.

    And if they are kept then they are happy genetic accidents.

    IOW the theory of evolution is all about the accumulation of genetic accidents!

    But how can we test that?

    How can we test the premise that teh bacterial flagellum evolved via an accumulation of genetic accidents?

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