>We must be very careful with falsification. Explanatory power is of equal or
>greater importance. Omnipotent explanatory theories are to be avoided,
>however. They explain everything and thereby nothing. It is very easy to use
>Popper naively, and its utility declines as the scope of the theory increases.
>For example:
>
The Biblical account of creation has a lot of explanatory power also.
If God can form Adam from the dust of the ground, then God may have done
something similar on other creation "days." This claim has great
explanatory power regarding a possible cause of what I acknowledge to be
the scientifically certain sudden appearance of virtually the whole of the
animal kingdom 453 million years ago at the cambrian explosion. (See Time
Magazine 12.4.95)
The second half of the above-mentioned Time article contains a lot of
speculation regarding naturalistic explanations for the sudden appearance
of the Cambrian body plans.
But when we ask, "Can any of these speculations be written as testable
mechanisms?" the fog clears and we see that the speculations are not
testable mechanism proposals, but instead they are guesses as to what the
conditions were at the time of the explosion.
But the conditions present at an explosion do not necessarily cause the
explosion.
JC>Easy! "The cambrian explosion was caused by mass extinction of the
JC>proceeding vendobionts, leaving vacant niches".
Mass extinction is not necessarily a mechanism of speciation, much less a
testable mechanism. It is merely a condition that might have preceeded the
explosion. Even if the condition of extinction is verified, it did not
necessarily cause the explosion.
I challenge anyone on this list to provide a testable causal mechanism that
caused the cambrian explosion.
I'm looking for something that has a falsifiability scenario that parallels
the "no-red-shift-is-discovered" scenario that Einstein described for
falsifying general relativity (i.e. if light from distant galaxies is
blue-shifted, then general relativity is falsified)
*I'm not looking for an environmental condition that merely corresponds
with the Cambrian explosion.
*I'm looking for a testable causal mechanism that actually causes the
effects we see in the Cambrian explosion.
Here are a few excepts from the Time Magazine article of 12/4/95. The
first experpt gives context. Then I present some excerpts that contain
what the author apparently hopes the readers will interpret as mechanisms
of the speciation that occured during the explosion.
These are examples of what would *not* meet my challenge. (I suspect many
Time readers assume the below-quoted speculations are science simply
because they come from the mouths of scientists.)
I make parenthetical comments after each excerpt.
===========Time Magazine December 4, 1995== CONTEXT================
COVER STORY
WHEN LIFE EXPLODED
For billions of years, simple creatures like plankton, bacteria and algae
ruled the earth. Then, suddenly, life got very complicated
BY J. MADELEINE NASH
[...]
while most people cling to the notion that evolution works its magic over
millions of years, scientists are realizing that biological change often
occurs in sudden fits and starts.
[...]
All around the world, in layers of rock just slightly younger than that
Erwin discovered, scientists have found the mineralized remains of
organisms that represent the emergence of nearly every major branch in the
zoological tree.
[...]
Where did this extraordinary bestiary come from, and why did it emerge so
quickly? In recent years, no question has stirred the imagination of more
evolutionary experts, spawned more novel theories or spurred more far-flung
expeditions. Life has occupied the planet for nearly 4 billion of its 4.5
billion years.
But until about 600 million years ago, there were no organisms more complex
than bacteria, multicelled algae and single-celled plankton.
[...]
Then, 543 million years ago, in the early Cambrian, within the span of no
more than 10 million years, creatures with teeth and tentacles and claws
and jaws materialized with the suddenness of apparitions.
In a burst of creativity like nothing before or since, nature appears to
have sketched out the blueprints for virtually the whole of the animal
kingdom. This explosion of biological diversity is described by scientists
as biology's Big Bang.
Over the decades, evolutionary theorists beginning with Charles Darwin have
tried to argue that the appearance of multicelled animals during the
Cambrian merely seemed sudden, and in fact had been preceded by a lengthy
period of
evolution for which the geological record was missing. But this
explanation, while it patched over a hole in an otherwise masterly theory,
now seems increasingly unsatisfactory.
========Time Magazine December 4, 1995==Bogus MECHANISM #1==========
So around 550 million years ago, Erwin and the others believe, some
wormlike creature expanded its Hox cluster, bringing the number of genes up
to six. Then, "Boom!" shouts Jablonski. "At that point, perhaps, life
crossed some sort of critical threshold." Result: the Cambrian explosion.
(OOOOOH! That explains it! Wait. Now how did the worm-like creature
expand it's Hox cluster? Can I expand my Hox cluster? What's the first
step in doing that? Is there really a mechanism here? Neal Roys)
========Time Magazine December 4, 1995==Bogus MECHANISM #2==========
The proliferation of wildly varying body plans during the Cambrian,
scientists reason, therefore must have something to do with Hox genes. But
what? To find out, developmental biologist Sean Carroll's lab on the
University of Wisconsin's Madison campus has begun importing tiny velvet
worms that inhabit rotting logs in the dry forests of Australia. Blowing
bubbles of spittle and waving their fat legs in the air, they look, he
marvels, virtually identical to their Cambrian cousin Aysheaia, whose
evocative portrait appears in the pages of the Burgess Shale. Soon Carroll
hopes to answer a pivotal question: Is the genetic tool kit needed to
construct a velvet worm smaller than the one the arthropods use?
(Even if the tool kit is smaller, this would tell us nothing of a
mechanism. These guys are looking only for verification with no
falsification scenario to give them perspective. Neal Roys)
========Time Magazine December 4, 1995==Bogus MECHANISM #3==========
Already Carroll suspects that the Cambrian explosion was powered by more
than a simple expansion in the number of Hox genes. Far more important, he
believes, were changes in the vast regulatory networks that link each Hox
gene to hundreds of other genes. Think of these genes, suggests Carroll, as
the chips that run a computer. The Cambrian explosion, then, may mark not
the invention of new hardware, but rather the elaboration of new software
that allowed existing genes to perform new tricks.
(Aren't we all very familiar with vast computer networks increasing in
complexity *without* the influence of an intelligent systems designer?
Seriously, people who are impressed with this article must be completely
blinded by their worldview of philosophic materialism. Neal K. Roys)
========Time Magazine December 4, 1995==Bogus MECHANISM #4==========
Of course, understanding what made the Cambrian explosion possible doesn't
address the larger question of what made it happen so fast. Here scientists
delicately slide across data-thin ice, suggesting scenarios that are based
on intuition rather than solid evidence. One favorite is the so-called
empty barrel, or open spaces, hypothesis, which compares the Cambrian
organisms to homesteaders on the prairies. The biosphere in which the
Cambrian explosion occurred, in other words, was like the American West, a
huge tract of vacant property that suddenly opened up for settlement. After
the initial land rush subsided, it became more and more difficult for naive
newcomers to establish footholds.
(Thin ice is right. So the truth finally comes out. This is all
speculation that is made to look credible by telling heart-warming stories
about the American West. Neal Roys)
========Time Magazine December 4, 1995==Bogus MECHANISM #5==========
Predation is another popular explanation. Once multicelled grazers
appeared, say paleontologists, it was only a matter of time before
multicelled predators evolved to eat them.
(Aha! So the mechanism is TIME. It's *ONLY* a matter of time! What do
they take me for? A Moron? This is actually quite comical. Neal Roys)
========Time Magazine December 4, 1995==Bogus MECHANISM #6==========
And, right on cue, the first signs of predation appear in the fossil record
exactly at the transition between the Vendian and the Cambrian, in the form
of bore holes drilled through shelly organisms that resemble stacks of
miniature ice-cream cones.
(I like that "right on cue" part. Hmm. Can someone tell me who's doing
the cueing? Neal Roys)
========Time Magazine December 4, 1995==Bogus MECHANISM #7==========
Seilacher, among others, speculates that the appearance of
protective shells and hard, sharp parts in the late Precambrian signaled
the start of a biological arms race that did in the poor, defenseless
vendobionts.
========Time Magazine December 4, 1995==Bogus MECHANISM #8==========
Even more speculative are scientists' attempts to address the flip side of
the Cambrian mystery: why this evolutionary burst, so stunning in speed and
scope, has never been equaled.
(The key word here is *speculation." A responsible scientific theory is
testable. Until the speculation is framed as a testable hypothesis that is
both verifiable and falsifiable, we have creative writing at best and more
likely spiritually deadly philosophy. Neal K. Roys)
Neal Roys
Math Teacher
Youth Pastor
Mundelein, IL