" If the results of his team's genetic study are correct,
Hedges says the scientific question must change from "How
did all these species evolve so suddenly early in the Cambrian
period?" to "Why don't we see any fossils of these species
long before the Cambrian period?" Among the suggested
answers are that changes in the Earth's atmosphere led to
the development of hard external skeletons in animals that
had only soft external skeletons before the Cambrian period.
"Hard body parts like external skeletons are most likely to
become fossils," Hedges explains. Species not likely to
fossilize, like earthworms, typically live and die without
leaving a trace of their existence--except in the genes of
their descendants. "
> "Some scientists have theorized that the ancestors of creatures that
>suddenly and mysteriously appeared in the Cambrian era may have been
>boneless creatures that could not be captured in the fossil record. But
>this explanation for a pattern of Darwinian evolution is weakened by the
>presence of soft-tissued fauna in the China fossils, and the persistent
>absence of those forms, or those of ancestors of them, in the earlier
>geological record also available at the Chengjiang site. Professor Chen
>insisted that the biological ãexplosionä exhibited at Chengjiang is not
>an illusory artifact of an incomplete fossil record, but an accurate
>preservation of the true history of life on earth. Accordingly,
>biologists should construct theories of lifeâs origin in light of this
>paleontological evidence, not in spite of it."
Where will naturalistic science go with this?