Did anyone else get a chance to review the most recent issue of
_Time_ magazine: "Evolution's Big Bang"? It's cover story is on the
most recent discoveries related to the Cambrian explosion. The
article is numbingly similar to a recent article on this subject
in _National Geographic_, Vol. 184, No.4, Oct. 1993. They even
ripped-off some of the same pictures! The article is more
up-to-date and discusses some of the most recent discoveries like
those reported in _Science_ "Biostratigraphic and Geochronological
Constraints of Early Animal Evolution" Vol. 270, pp 598-604,
Oct. 27, 1995. The more recent discoveries have continued to
collapse the Cambrian era into an ever increasingly spectacular
explosion. The current estimates for the time of the explosive
phase of the Cambrian era is 5-20 million years. An excerpt from
the National Geographic article (page 125) reads as follows:
"So far the team has found five distinct animal communities, each from
a different environment, that were buried at different times over several
million years. Collins sees little evolutionary change among these
animals, which indicates that by Burgess times the explosive phase of
the Cambrian was spent. "New fossils found in China and Greenland look
very much like the Burgess animals," says Collins. "Yet they are up
to 15 million years older."
Moreover, new radiometric dates indicate that the Cambrian had begun
barely ten million years before the Chinese fossils lived. Therefore,
the modern animal groups emerged almost at once - making the Cambrian
explosion appear to be the big bang of zoology."
The latest issue of _Time_ takes the report a step further and almost
flirts with disaster in the following:
"The more scientists struggle to explain the Cambrian explosion, the
more singular it seems. And just as the peculiar behavior of light
forced physicists to conclude that Newton's laws were incomplete, so
the Cambrian explosion has caused experts to wonder if the twin
Darwinian imperatives of genetic variation and natural selection
provide an adequate framework for understanding evolution. 'What
Darwin described in the _Origin of Species_,' observes Queen's
University paleontologist Narbonne, 'was the steady background kind
of evolution. But there also seems to be a non-Darwinian kind of
evolution that functions over extremely short time periods - and
that's where all the action is." (page 74)
The writers of this article once again called in the trouble-shooting
team from 'Complexity Analysts, Inc.' Citing Stuart Kauffman who
spins his order-from-chaos and self-organization stories to explain
this difficult phenomena. This is the same guy _Time_ called
"suspiciously trendy" and "new age" and "at best inchoate but fruitful
and, at worst inchoate and sterile" in their Dec. 28, 1992 article on
spontaneous origin-of-life theories. Stuart Kauffman didn't get
dis'ed in this article. Perhaps it finally dawned on the writing
staff of _Time_ that if new complexity theories fail, they may be
left without a theory.
The Cambrian explosion falsifies an earlier prediction of
evolutionary theory: diversity should precede disparity. This
is artistically represented in Ernst Haeckel's "Tree of Life."
It is a necessary prediction from the classical (gradualistic)
theory of evolution. But the dominant pattern throughout the
fossil record - and especially in the Cambrian fossils - is that
disparity precedes diversity. Stephen Jay Gould makes this point
in his book _Wonderful Life_ as he notes that we have been viewing
the cone of life backwards.
God Bless,
-jpt
--John P. Turnbull (jpt@ccfdev.eeg.ccf.org)Cleveland Clinic FoundationDept. of Neurology, Section of Neurological ComputingM52-119500 Euclid Ave.Cleveland Ohio 44195Telephone (216) 444-8041; FAX (216) 444-9401