talk.origins #23493 (41 more) \-(1)--(1)+-(1)--(1)
From: 00prneubauer@bsu-ucs.uucp (Paul Neubauer) |-(1)--(1)
[1] Re: "Evolution, a Theory in Crisis" |-(1)
Date: Thu Mar 12 16:15:11 CST 1992 \-(1)
Lines: 72 -( )--(1)+-(1)
+ \-[1]
No doubt I am about to stick a big, fat foot into my big, fat mouth,
(since I have not read Denton's book) but here goes anyway. (And at
least I am confining myself to something I think I might understand :-).
In article <2876@daily-planet.concordia.ca>, gsmith@concour.cs.concordia.ca
(Gene Ward Smith) writes:
(And in another article, Gene writes:
>In case it isn't obvious, globally swap Dutton to Denton in my reply to
>Bruce Salem.
so I have.)
> In article
> salem@pangea.Stanford.EDU (Bruce Salem) writes:
>>Also, men and mice might be substancially
>>similar when compared to tuna, by this measure? The former are placential
>>mammals and a tuna is a boney fish. The Primates and Rodants radiated
>>from ancestral stock at about the same time (50 Million years ago)
>>whereas the boney fish appeared about 150 million years ago.
>
> That is why I also brought in frogs and tuna, for which Denton
> claims the same phenomenon occurs. He also says a tuna is no
> more close to a shark than a human is, for instance.
Actually, I think that Bruce has a point here (not that I think Bruce
has never had points before, mind you). The point is that all of
humans, mice and tuna would have diverged from the common stock with
sharks at the same time so you should expect tuna, frogs, mice and
humans to be equally distant from sharks. I would also expect tuna
and mice to display approximately the same degree of difference from
each other as tuna and humans display and similarly, by this criterion
(as Bruce points out) mice and humans ought to display more similarity
than mice or humans to tuna.
Crudely, as far as I know, something like the following relationship
tree ought to hold. I would expect similarities to correspond to
closer branches on such a tree and I would expect (by the molecular
clock theory at least) that ALL leaf nodes that descend from a given
branching node would be equally distant from any particular leaf node
that does not descend from the specified branch node.
cartilaginous fish A sharks
--------------------+--------------------------------------------
|
| boney fish C tuna
+---------------+----------------------------
B |
| frogs
| +------------------------
| |
| | mice
| | +---------
| | |
+---+--------------+F
D E | humans
+---------
Now the question is "Does Denton's data show anything different that
would not be expected from such a tree?" I have already admitted that
I have not read the book, so I am prepared to be embarressed, but none
of the points you have cited so far have spoken to anything resembling
a problem for such a tree (which, after all, is pretty conventional).
That is, specifically, since tuna, and humans (for example) both
descend from node C and sharks do not, it should be expected that tuna
and humans are equally different from sharks, i.e., "a tuna is no more
close to a shark than a human is".
Or am I missing something big?
--
Paul Neubauer 00PRNEUBAUER@BSUVAX1.BITNET 00prneubauer@leo.bsuvc.bsu.edu
00prneubauer@bsu-ucs.UUCP neubauer@bsu-cs.UUCP
