Re: Limits of Kinds - now its crabs

Glenn Morton (
Mon, 17 Nov 1997 22:33:18 -0600

Hi Art,

At 09:54 PM 11/17/97 -0800, Arthur V. Chadwick wrote:

>I don't know any informed creationists ("YEC" or otherwise) who believe
>there has been no change. This is a straw man argument as Gould himself
>I maintain that creationists also mean that the group (genus, family, etc)
>has remained static for a long time (but much less time than the
>evolutionist asserts).

I have a question then, how can a slow rate of change disprove evolution?
Where is it written that evolution must proceed at 50 darwins per
year/millennia/million year and if it drops below this rate, it is not
evolution? I can't understand how a slow rate of change disproves evolution
which is why these living fossils are advanced by creationists. It would
be like saying that a slow moving creek disproves the theory that creeks
flow to the sea. And I might add, that when I was a YEC I was under the
impression that these living fossils were the same species. Maybe I was
dumb, but I think most lay people think the same thing. Remember that I
started out with a layman's knowledge of biology and geology and got my info
from ICR.

>>Maybe the issue should be re-directed. How do you quantify how much
>>morphological change has occurred. To use the crabs on my web page as
>>evidence of a living fossil is clearly wrong.
>Not necessarily. If that is the extent of change in 200 million years,
>that is remarkable. They are clearly similar. The forms from the Permian
>and Silurian shown on page 563 of Shrock & Twenhofel (respectively
>Paleolimulus and Neolimulus -- the extant genus is Limulus) even more
>clearly represent remarkable stasis, as the choice of the genus names
>indicates, as well as the obvious similarity of the forms.

But once again, there is considerable morphological change. Look at the
difference in the position of the legs of Paleolimulus on page 563 compared
to the legg orientation on p. 562. The legs stick out from something (I
don't know the anatomical name) in Paleolimulus, that something is missing
in Limulus and the legs point backwards. Limulus, the modern crab has six
legs I count 5 on Paleolimulus (assuming the anterior thing is a leg it is
unclear to me) Looking at the pictures one can easily see the differences
between the Permian Paleolimulus,the Silurian Neolimulus, the pennsylvanian
Euproops, and the devonian Koenigiella. When I think of things being similar
I think of things that make me have to study them to differentiate them.
Twins have a remarkable similarity; my brother and I were easily
distinguishable from a glance

Using what I can determine of your criteria of morphological change, one
would have to remark that modern fish are remarkably unchanged from Devonian
fish. Yet their isn't an ichthyologist who can't tell them apart
instantly. The same must be said of trees which would have to be remarkably
unchanged also.


Foundation, Fall and Flood