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Study Explains Evolution's Molecular Advance

Posted by ryuzaki0 on from the good-for-some-bad-for-others dept.

pnewhook writes "The New York Times is reporting that 'by reconstructing ancient genes from long-extinct animals, scientists have for the first time demonstrated the step-by-step progression of how evolution created a new piece of molecular machinery by reusing and modifying existing parts. The researchers say the findings, published today in the journal Science, offer a counterargument to doubters of evolution who question how a progression of small changes could produce the intricate mechanisms found in living cells.'"

2 of 477 comments (clear)

  1. Reducible Complexity by posterlogo · · Score: 4, Informative
    The study is a fascinating one. If you have a subscription to Science, I suggest reading the summary of the research by Cristoph Adami termed "Reducible Complexity." I'm sorry I don't know how to get that article to those without a subscription but I can give a lay-man's summary here. Although the original research did not specifically mention evolution vs. intelligent design, they essentially disproved the central tenet of ID, that of "irreducible complexity." IC states that some things are so complex, they look like a "lock and key" mechanism -- one could not have be made without the other "in mind" -- thus they must both have been designed. The research that is the focus of this article described two different hormones with two different receptors. Both look like lock and key systems. By tracing evolutionary lineages, the authors of the study showed how a series of mutations, as little as 2, occuring sequentially by random could have led to the two divergent lock and key systems from a single precursor. As an academic biologist, I really think this elegant study is one of the nicest pieces of evolution research to come out recently. It truly addresses a problem even Darwin admitted was a caveat (though Darwin also offered the solution, which was indeed confirmed here).

    The solution is that the original precursor gained the ability to bind a new hormone by a single point mutation, and this did not disrupt the ability of it to bind its old hormone. The new receptor then diverged and through a well known process of gene duplication, begat multiple and independently evolving molecules. One retained the function of binding the old hormone, whereas another mutated further to lose the ability to bind the old hormone and could now only bind the new hormone. Viola -- two seemingly "designed" systems out of one precursor -- evolution at its finest, and IMHO, damning evidence against the basic principle of Intelligent Design.

    On a personal note, it never fails to amaze me how much people deny the intelligence of humans to figure things out... the old "just because we can't explain it now, it must have be an unexplicable force, like God." I'm sure lightning and earthquakes seemed supernatural too. Evolution is no different -- it can be dissected and explained.

  2. Re:Matter of time by monoqlith · · Score: 5, Informative

    Sorry to nitpick, but quantum "fluctuations" are not random. People often confuse the terms "random" and "probabilistic" when they talk about quantum physics. A "random" system is a system where any outcome of measurement is just as likely as any other outcome. However, quantum particles are more likely to be at the expectation value of position than at any other place, though there is a NON-zero probability of it being anywhere else in the system. So quantum "fluctuations"(I'm not sure what you mean by this) are NOT random, because some outcomes of measurement are vastly more likely than others. The only requirement for a quantum particle is that the probability of it being SOMEWHERE is 1.

    Quantum particles are associated with probability WAVES that fluctuate with time. When we say wave-particle duality we mean that the particle does NOT have a definite classical trajectory but instead a WAVE of probability associated with it that describes the positions, energies, and momentums at which the particle is most likely to be. This is called a wave function; it is a solution to Schrodinger's differential wave equation and its square is a probability curve.

    Depending on your interpretation, quantum mechanics does indicate some things about reality such as there is an ONTOLOGICAL limit on what we can know for certain about objective reality such that it appears meaningless to talk about an absolute objective reality at all. That is, reality changes by being observed. However, unlike general relativity which does indeed EXPLAIN gravity by saying that gravity is identical with a curved space-time geometry, you are quite right in saying that quantum mechanics does not explain anything. Nor does particle theory or E&M explain why there are electric and magnetic forces without beginning to conjure up force-carrying particles and the like. They are currently trying to explain all these things by means of string theory.