Re: problem

Glenn R. Morton (grmorton@waymark.net)
Wed, 19 Aug 1998 21:20:31 -0500

At 01:22 AM 8/19/98 -0700, Cliff Lundberg wrote:
>Pim van Meurs wrote:
>
>> What interest do you have with the Cambrian Explosion ?
>> From what I understand, this is indeed a remarkable era
>> and has received significant scientific study. So what
>> would you like to discuss about the Cambrian Explosion
>> that you feel has not received just examination ?
>
>The sudden appearance of so many complex organisms conflicts
>pretty severely with gradualism. I wondered why many critics
>of evolution dwell on some controversial particular while the
>biggest puzzle is scarcely mentioned.
>
>I am an evolutionist who accepts the evidence at face value,
>meaning I believe there was a very rapid formative process that
>created the major types of organisms, a process that apparently
>has not operated since the Cambrian. As to the nature of this
>process, I suppose it involved mutations and hybridizations we
>might call bizarre.

Cliff,

You might be aware that the Cambrian explosion is beginning to look a bit
less explosive.

"The presence of possible amphiblastula larva suggests that the calcareous
sponges may have an extended history in the Late Precambrian. The fauna
indicates that animals lived 40 to 50 million years before the Cambrian
Explosion." ~ Chia-Wei Li, Jun-Yuan Chen and Tzu-En Hua,"Precambrian
Sponges with Cellular Structures," Science 279(1998):879-882, p. 879

Molluscs have been found in the Precambrian:

"The fossil Kimberella quadrata was originally described from late
Precambrian rocks of southern Australia. Reconstructed as a jellyfish, it
was later assigned to the cubozoans ('box jellies'), and has been cited as
a clear instance of an extant animal lineage present before the cambrian.
Until recently, Kimberella was known only from Australia, with the
exception of some questionable north Indian specimens. We now have over
thirty-five specimens of this fossil from the Winter Coast of the White Sea
in northern Russia. Our study of the new material does not support a
cnidarian affinity. We reconstruct Kimberella as a bilaterally
symmetrical, benthic animal with a non-mineralized, univalved shell,
resembling a mollusc in many respects. This is important evidence for the
existence of large triploblastic metazoans in the Precambrian and indicates
that the origin of the higher groups of protostomes lies well back in the
Precambrian." ~ Mikhail A. Fedonkin and Benjamin M. Waggoner, "The Late
Precambrian Fossil Kimberella is a Mollusc-like Bilaterian Organism,"
Nature, 388(1997):868-871, p. 868

Multicellular animals are quite old,
"The Tuanshanzi fossils we have described imply that megascopic
multicellular organisms originated at 1700 Ma or earlier." ~ Zhu Shixing
and Chen Huineng, "Megascopic Multicellular Organisms from the
1700-Million-Year-Old Tuanshanzi Formation in the Jixian Area, North
China," Science, 270, Oct. 27, 1995, p. 622 (p. 520-622)
glenn

Adam, Apes and Anthropology
Foundation, Fall and Flood
& lots of creation/evolution information
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