On 17 Jul 95 10:45:40 EDT you wrote:
>Stephen writes:
SJ>I can see nothing that would suggest a genetic mechanism that could
>change a mesonychid into an ambulocetus.
JB>I've uncovered one over the course of the last few weeks: Wishful
>thinking. But why is this mechanism never mentioned in evolutionist
>texts?
It is! It's called an abracadabra:
"The abracadabra approach used to explain away the fossil gaps is
equally in evidence when it comes to evolutionary novelties. With a
wave of the wand, difficulties and complex ities are minimized. Thus
the truly vast anatomical steeple chase that has to be run to turn a
small hoofed animal (presumably) into a whale becomes:
`The major differences between the whales and the early mammals are
attributable to adaptions for the swimming life. The forelimbs have
become paddles. The rear limbs have been lost altogether, though
there are a few small bones buried deep in the whale's body to prove
that the whale's ancestors really did, at one time, have back legs.'
(Attenborough D., "Life on Earth", Collins, London, 1979, p240)
Darwin himself offered a prime abracadabra on the subject
`I can see no difficulty in a race of bears being rendered, by natural
selection, more and more aquatic in their habits with larger and
larger mouths, tiII a creature was produced as monstrous as a whaIe.'
Darwin C., "The Origin of Species", 1859).
(Hitching F., "The Neck of the Giraffe: Where Darwin Went Wrong",
1982, Ticknor & Fields, NY, p97,100)
Seriously though, I have re-read Gould's chapter in HT&HT and it
appears that homeosis only refers to segemented body parts, eg.
arthropods:
"Homeosis is not peculiar to fruit flies, but seems to be a general
phenomenon, at least in arthropods...
Homeosis is easiest to demonstrate in arthropods with their
characteristic body plan of discrete segments with different and
definite fates in normal development, but common embryological and
evolutionary origins. Yet analogous phenomena have been noted again
and again in other animals and plants with repeated parts..."
(Gould S.J., "Hen's Teeth and Horse's Toes", 1984, Penguin, p192-194)
It doesn't seem all that able to describe the sort of complex changes
needed to change a land mammal into a whale.
God bless.
Stephen
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