Cetacean evolution and Michael Denton

<drsyme@cablespeed.com> writes:
... there was a rapid change in EQ, due to both increase in brain size and
reduced body size, that quadrupled the EQ about 35 to
37 million years ago... I just find it interesting that they attribute a
relatively rapid, but significant change to one ability, echolocation and
dont seem to imply any transitions between the archaeoceti and odontoceti,
like suddenly this ability appeared out of nowhere and was the cause of,
or the result of, increased encephalization.

ED: The cetaceans did not appear out of nowhere, neither where they fully
specialized when they first took to the water. And of course the earlier
forms simply went kaput. The Baleen whales never even evolved
echolocation. And we can approximate the point when the toothed-whales
and Baleens diverged. There's even a fossil cetacean specimen with half
teeth and half baleen!

Also about echolocation, scientists don't even know whether all toothed
whales have that ability, only that most toothed whales, such as dolphins,
river-dolphins and porposes, can echolocate, and they all seem to be
pretty closely related, evolutionarily speaking. Nor do scientists even
know how the sounds are formed. The sound is believed to be focused by
fatty tissues in the melon (the lump that these animals have on their
noses).The received echoes pass through conducting tissue in the lower
jawbone to the inner ear. Scientists do not agree about where the sound
comes from. Some scientists suggest that sound is emitted from a nasal
plug and that the shape of the melon is altered by muscles to focus sound.
Other scientists believe that the larynx emits sound and argue that
echolocation focusing is achieved by bouncing sound off various parts of
the skull.

Also, since echolocation depends on a large fatty deposit in the front of
the skull it's not exactly like building the bones of the middle ear. Yet
we know that reptiles existed that you can't even tell from early mammals,
and the primary difference from the fossils of early mammals that followed
them was that the mammal-like reptiles had jaws made of multiple bones,
while the early mammals had a jaw made of a single bone. The jawbones of
those mammal-like reptiles also had the extra bones located near the ends
of the jaws, near their ears. Compare that with the fact that in the
embryoes of modern day mammals you can see the three inner ear bones of
mammals being formed from material in the jaw.

What all of this says to me, as well as the genetic evidence, is that the
"gaps" are not unbridgeable between species. And in fact, the genetic
difference between humans and chimps is no greater than the genetic
distance between sibling species of fruit flies, and nobody doubts that
they evolved, as on the islands of Hawaii, which features hundreds of
fruit fly species seen no place else on earth, and which have evolved to
live on beaches, mountainsides, valleys, jungles, and subsist on different
foods.

Or as Michael Denton, one of the fathers of the Intelligent Design
movement said in his second book:
"One of the most surprising discoveries which has arisen from DNA
sequencing has been the remarkable finding that the genomes of all
organisms are clustered very close together in a tiny region of DNA
sequence space forming a tree of related sequences that can all be
interconverted via a series of tiny incremental natural steps."
"So the sharp discontinuities, referred to above, between different organs
and adaptations and different types of organisms, which have been the
bedrock of antievolutionary arguments for the past century (3), have now
greatly diminished at the DNA level. Organisms which seem very different
at a morphological level can be very close together at the DNA level."
Even at the ARN website you can read about Denton arguing pro-evolution to
Paul Nelson (of the Discovery Institute) on their way to a "Mere Creation"
conference: Paul says "common ancestry is an assumption." Denton says,
"the such-and-such goes down and around the something else and why doesn't
it just go straight across?" And Paul says, "But how do you know that the
down and around isn't optimal?" I remember that point. Then Denton says,
"Yeah but when you have delivered as many babies as I have you notice
things." He gestures downward with both hands cupped as though he is about
to deliver one. He says "Right after they are born they go like this"--he
then does a grasping motion with both hands raised. In my semi-fevered
state I saw a new born hominid grasping its mothers' fur--right there in
the van. He gave a name for the reflex [primate grasp] but even without it
I could see that he knew a thing or two about how our kind and kin are
born.
Received on Sat Nov 6 00:27:33 2004