stasis

Life forms that never change are telling us something about evolution. Why avoid it?, David Tyler asks

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credit Hwaja Goetz

Following up his comments on the stunning half billion years of changelessness (stasis) demonstrated by the pterobranch, David Tyler now addresses the unchanging cricket, one of whose fossils was found from 100 million years ago: He comments on howthe fact that many life forms seem motionless in time is handled in the science literature:

It is of interest to note how living fossils are described. Sometimes, they are “some of evolution’s greatest survivors”, and the splay-footed cricket is “obviously doing something right”. The Economist reporter says that the insect illustrates the “first rule of natural selection”: “If it ain’t broke, don’t fix it.” LiveScience took a different view, making the point that the animal has been “stuck in time for the past 100 million years or so”. Evolutionary theory wins all ways: if the animals document stasis, then they are fit for their environment and the environment has not changed with time. If they document change, then natural selection is at work, acting on natural variations. Images of the modern cricket are here and here.The problem with evolutionary theory today is that it finds nothing significant to learn from these examples of stasis. “If it ain’t broke, don’t fix it” seems to exhaust their mental powers. However, there are a host of issues waiting to be explored: What do these organisms tell us about limits to variation? What can be learned about biological innovation? Can microevolution be extrapolated to macroevolution? Is it realistic to expect environments to show the same stasis as these animals and plants? Living fossils are not just quirky – they are telling us something significant about the biological world. More here.

4 Replies to “Life forms that never change are telling us something about evolution. Why avoid it?, David Tyler asks

  1. 1
    Joseph says:

    Let us not forget all those new genes in fruit flies– 35 million years and thos new genes to make a fruit fly out of a fruit fly.

    Powerful stuff…

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  3. 3
    Joseph says:

    Electric eels- a type of fish- generate their voltage using the SAME ions that are used to help it move- the SAME ions we use to help us move and live- NA, K and Ca. Wet electricity used in a wet environment!

    Nice common design…

  4. 4
    NeilBJ says:

    I view natural selection as a gate keeper, if you will. To state the obvious, nature must first present something to select before natural selection can act upon it.

    This prompts a question regarding mutation rates or the nature of the mutations.

    In the case of the 100 million year old cricket, it would seem that either the mutation rate would have to be reduced to near zero, or the mutations that do occur would have to be all neutral.

    The evolution of the whale presents the opposite problem. Mutation rates would have to occur much faster than normal and/or would have to be more “clever” than normal to accomplish the great morphological transformations that resulted in the whale.

    If it ain’t broke, don’t fix it does not solve the problem I see. If indeed the mutation rates have changed, how can that hypothesis be tested other than by assuming that evolution is true in the first place and concluding that vastly different mutation rates must be the explanation?

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