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ORIGINAL: DanJames
Think I should just throw it out there and see if anybody bites?

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As for your original question, I think stasis does present a challenge to evolution, but it's not a fatal flaw.

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ORIGINAL: Jhud
What evolution seems to fail to account for in this scenario is the extreme stasis of certain organisms over lengthy geological periods.

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Whatever legitimate challenge stasis poses for evolutionary theory, extended periods of stasis are only observed for some, not all, species. The many examples of non-stasis show, almost by definition, evidence of evolution. If it's not static, it's changing over time. Evolutionary theory may need to be modified in some way to better explain stasis, but stasis does not nullify the facts of evolutionary change-over-time.

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ORIGINAL: essentialsaltes

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ORIGINAL: Jhud
What evolution seems to fail to account for in this scenario is the extreme stasis of certain organisms over lengthy geological periods.

Since I'm not allowed to say this elsewhere...

Whatever legitimate challenge stasis poses for evolutionary theory, extended periods of stasis are only observed for some, not all, species. The many examples of non-stasis show, almost by definition, evidence of evolution. If it's not static, it's changing over time. Evolutionary theory may need to be modified in some way to better explain stasis, but stasis does not nullify the facts of evolutionary change-over-time.

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ORIGINAL: DanJames
The fact that there is a great deal of stasis in the fossil record, that [bmany species "appear", "stay the same", and are still the same animal today poses an interpretation that they are simply the same animals that we have today, just buried.

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Perhaps (that's a big perhaps) what needs to be reevaluated is how we interpret the fossil record itself because you would not predict hundreds of millions of years of stasis if we are all evolved from the same common ancestor.

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Depends on how many 'many' is. There are also many examples of change-over-time. There are no austrolopithecenes alive today. No tyrannosaurs. No eohippi, trilobites, megatheria, ad infinitum. Some of these went extinct leaving no similar relatives, other things have modern relatives living today in a different form. Transitional fossils exist that connect the old forms to the modern ones.

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I don't see how having a common ancestry necessarily means we would predict no stasis. If some branch of our giant family tree wandered into a comfortable niche, there's no selective pressure for that species to change.

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ORIGINAL: Jhud

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Depends on how many 'many' is. There are also many examples of change-over-time. There are no austrolopithecenes alive today. No tyrannosaurs. No eohippi, trilobites, megatheria, ad infinitum. Some of these went extinct leaving no similar relatives, other things have modern relatives living today in a different form. Transitional fossils exist that connect the old forms to the modern ones.

Well, they certainly all 'went extinct', which is a particularly unfortunate sort of change (especially eohippi, which would make particularly good pets) but whether they are particularly ancestral to anything is another question.

Indeed, one interesting thing about trilobites is not only did they 'go extinct', but the variability within the class seems to have decreased over time. Natural selection winnowed them, it didn't promote variety.

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I don't see how having a common ancestry necessarily means we would predict no stasis. If some branch of our giant family tree wandered into a comfortable niche, there's no selective pressure for that species to change.

Well, if 'common ancestry' is a product of evolution, which is itself the product of gradual changes being acted upon by NS, then those organisms which weren't gradually changing and being acted upon by NS would seem excluded from that tree, or at least only a side note to it.

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Indeed, considering those organisms that display stasis, like jellyfish, sponges, various arthropods, etc, major portions of the trunk of our presumed family tree would seem to have been 'comfortable' for some time.

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How do you know they were not gradually changing? Didn't we go over this earlier in this thread? You must have really bad memory.

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ORIGINAL: alex123
Not so. The 'descent with modification' model of evolution is based on a huge mass of convergent evidence - a long history of sedimentary geology, datable to hundreds of millions of years by a variety of methods; a fossil record showing the appearance and disappearance of organisms within ecological assemblages over time; nested genetic and homologous relationships between species with ample evidence of divergence of inherited characteristiscs over time; and a mass of expertimental and observational evidence for mutation and natural selection as a mechanism for the inhertance of modification. And the interesting thing is that the further you go the less evidence there is for any form of guidance in evolution and therefore the less need there is to invoke any mechanism of direction or self-organisation. Faith is kicked firmly back to the belief systems of religion.