Echinoderm Roots - A Review
In Nature v. 430, 22 July 2004, p. 411, "Echinoderm Roots" by Andrew B. Smith is a review article. The strange kind of creature described above is called a vetulicolian, and this new report describes a similar yet new kind dubbed vetulocystids.
The review article says it is a "bold claim" for the researchers to describe this new kind of creature as (essentially) "the most primitive echinoderms yet known." It adds the warning, "But many pieces are still missing from this part of the fragmented puzzle."
Part of the problem (for evolutionists) is that all definite, extant echinoderms have a very distinctive body plan. Their "five-fold symmetry...sets them apart" and "The echinoderm skeleton is equally distinctive, being made of calcite plates with a microstructure that resembles a very holey Swiss cheese."
This description is almost derogatory, for the structure is a very intricate and well ordered pattern.
An article in Science News August 21, 2004, v. 166, p. 125, "Sea urchin shell lights the way for optical material" describes a sea urchin shell as "a highly organized network of microscopic channels" which "has a configuration similar to that of a photonic crystal," one of the most recent products of advanced human technology.
In fact, as originally described in the July Advanced Materials, researchers made a casting of a sea urchin shell, shrank it with heat, and obtained a mold for making a photonic crystal.
The review article says that "If" the researchers are correct, their research "links" echinoderms and the vetulicolians. However, it notes that "Fossils can be made sense of only by comparison with living organisms...But fossils such as the vetulocystids, whose affinity with living groups is not immediately apparent, pose a major difficulty."
It also shows how the mindset of scientists can alter the interpretation of the fossil record. "In the past they would have simply been hived off into their own higher taxonomic group...Nowadays, palaeontologists...strive to place such fossils into their appropriate branch in the tree of life, interpreting characters they display in the most plausible (or least implausible) way."
In other words, the evolutionary "tree" was starting to look too much like the creationists' "orchard" so now evolutionists are accepting any explanation that isn't obviously ridiculous in order to shove new forms into the smallest possible of existing classifications.
Here I am rambling on at length again, but the origin of echinoderms is an area that creationists haven't looked at very closely, and it's as problematic as most for the evolutionists.
Anyway, aside from these new fossils, the only other "important fossils" that "help bridge the gap between radiate echinoderms and other deuterostomes" are homalozoans. These also are entirely extinct, so there's no way to thoroughly test their supposed position on the tree. They do have "the characteristic skeleton of an echinoderm" and apparently (I assume there are fossils in various stages of development) "a strongly asymmetrical development" which is like echinoderms (that undergo a "bizarre asymmetrical transformation from larva to adult, which involves loss of the righ-hand set of paired larval body chambers"), however, "homalozoans never display even a hint of radiate symmetry and, more importantly, they have gill slits and a post-anal muscular appendage." Most of us would probably replace the last noun phrase with "a tail."
Evolutionists assume the "last two traits are probably primitive features common to all deuterostomes" (which is probably a major reason why they were/are so reluctant to give up on saying embryonic humans have gill slits and a tail), but since the asymmetry of larval echinoderms seems to consist merely or mainly of losing parts on one side and homalozoans are truly bizarre in not having any kind of symmetry at all, it seems to me that calling them a "bridge" is wishful thinking produced by faith rather than facts.
Another part of the problem is simply that evolutionists assume (until they can't help seeing for themselves) that common features are due to common descent, so basic common features which by their nature occur in a broad variety of organisms naturally create a lot of work for them. Echinoderms are lumped into a group "known as the deuterostomes" (I believe "deuterostome" can be roughly translated as "two holed" -- having both mouth and anus) and this basic classification includes everything from worm-like hemichordates to vertebrates (yes, that's humans, too).
These new vetulocystid fossils don't really help much. They're basically little rounded blobs with a sort of short tail or stem, with a couple circular features and a series of ridges in another area of the roundish part. The circular features appear to be openings "in the form of a low pleated cone" and so are reckoned as a mouth and possibly an anus, although one fossil (according to the original research report) has what might be an alimentary canal running down the length of the tail. The "rhomboidal structure" with the ridges is reckoned by the authors to be "respiratory in function and possibly a gill." Vetulocystids use as a bridge "hinges on" their having one -- but just one -- gill, "But other interpretations are possible. The two circular structures could be gill openings (they are in a similar position in vetulicolians) and the gill-like area could be another form of respiratory structure with no opening involved.
At any rate, these fossils do nothing to solve the problem of the Cambrian explosiion. "There is now direct fossil evidence that all of the major deuterostome groups were established by about 520 million years ago," including vertebrates. This includes another enigmatic form, "_Phlogites_, a tentacle-bearing early Cambrian fossil of uncertain affinity." "So, if deuterostome divergence occurred around 575 million years ago, as recent molecular-clock studies suggest, there is a 50-million-year gap in the fossil record." Whatever vetulosystids were, they appear in the same strata, not earlier, but it's no wonder evolutionists want to use them to cover up the gap rather than leave them as yet another mysterious form of their own.
The original research report is "Ancestral echinoderms from the Chengjiang deposits of China" by Shu _et al._, _Nature_ v. 430, 22 July 2004, p. 422. It points out that "the appearance of extinct intermediate forms" is "conjectural." it refers to the homalozoans as a "bizarre group of primitive echinoderms whose phylogenetic position has been highly controversial."
Until Next Time,
David Bump
