Re: transitional fossils

From: Pim van Meurs <>
Date: Tue Dec 06 2005 - 22:53:20 EST

Dr. David Campbell wrote:

>>No, that is not what the evidence is telling us. The fossil record
>>sometimes shows us minor morphological change for long time periods.
>And sometimes it shows us major morphological change in short time
Indeed, the fossil record is full of varying examples of evolution.

>>In other words, the fossil record is giving us the kind of resolution
>>we would need to test evolution. What we see is little or no change
>>for long periods, even 500 million years in the case of, say,
>>sipunculan worms.
>Sipunculans are practically unknown as fossils-there are some burrows
>probably attributable to them. You may be thinking of priapulids,
>which are common in the Burgess Shale. However, there are significant
>differences between the Cambrian priapulids and the modern ones.
>There are a few things with little change over very long periods of
>time; however, they are exceptional. In most cases there is quite a
>lot of change over time.
>My undergrad honors thesis, MS, and PhD all dealt with invertebrate
>paleontology and evolution. To the extent that we have looked, the
>patterns from paleontology fit evolutionary expectations. We can
>trace mollusks from a rather generic Precambrian form through a
>Cambrian diversification of basic body plans, Paleozoic
>diversification of major groups, various turnovers in form with
>extinctions and radiations, and eventually the modern diversity. We
>can trace from primitive chordates in the Cambrian to jawed fish to
>amphibians to reptiles to birds and mammals. The fossil record
>supports evolution. We don't have detailed explanations for the
>evolution of everything that has been seriously examined, much less
>for the vast majority of organisms that have not even been examined
>evolutionarily, but the patterns so far as we know them fit
>evolutionary expectations. We see fewer, simpler things giving rise
>to more, more complex things. Basic patterns are established, and
>then the range of available options within these patterns are
>established. Situations with little competition (invasion of new
>habitat, major morphological/behavioral innovation, vacancies created
>by mass extinction, etc.) lead to radiations.
Yes, even the Cambrian explosion which was initially considered to be
quite an enigma for evolutionary theory seems to become more and more
resolved as fitting well within a Darwinian paradigm.
The evidence of nested hierarchies and consistent phylogenies shows once
again what a powerful fact common descent is.

Michael Roberts wrote

>Funny but the fossil records tells me something different. Can you
explain why I only found one type of >Precambrian fossil as if there
had been little change I should have found many fossils in those strata?

How interesting, turning the Cambrian explosion into evidence against
Cornelius' claims. I am still curious as to how ID proponents explain
the Cambrian
Received on Tue Dec 6 22:55:59 2005

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