Naked Science Forum
Life Sciences => Plant Sciences, Zoology & Evolution => Topic started by: thedoc on 05/08/2015 06:50:01
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Liam Krut asked the Naked Scientists:
If mutations occur at a constant rate, why do we have living fossils? I would expect the accumulation of new genetic material to make things like ginkos and horse shoe crabs unrecognizable from their fossilized ancestors.
What do you think?
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If mutations occur at a constant rate, why do we have living fossils?
The mutants would only succeed if the mutation provided a benefit , otherwise they are an evolutionary cul-de-sac.
If the environment is constant, natural-selection (https://en.wikipedia.org/wiki/Natural_selection) will keep the design constant , once an optimum design has come about.
[ Note: Even though the body-plans of so-called "living fossils", have changed little over hundreds of millions of years, there will have been inconspicuous evolutionary changes, e.g. evolution of their immune-systems , as that milieu is not constant ].
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If mutations occur at a constant rate
Quite obviously, they don't, otherwise we wouldn't have long-lived species like ginko and horsehoe crabs. And people would evolve as quickly as cold viruses.
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Another reason that we have living fossils is that women continue to breed with obvious throwbacks like the current crop of GOP presidential candidates.
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I say, steady on, old chap. Are you suggesting that Jeb Bush, the brother of a towering genius, isn't in the running for a Nobel Prize and sainthood? Or that the intellectual quality of candidates has gone downhill since Ronald McDonald Reagan? Has that charming lady killed all the bears in Alaska and learned to read yet?
Democracy: government of the people (demos) by the worst (krassos). Where better than in America?