Re: transitional fossils

From: Pim van Meurs <pimvanmeurs@yahoo.com>
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
>periods.
>
>
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

This archive was generated by hypermail 2.1.8 : Tue Dec 06 2005 - 22:55:59 EST