[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re: No Hedging.




On Wed, 20 May 1998, chris brochu wrote:
> This quote indicates some ignorance on Hedges' part

> This quote by Hedges, by the way, is not surprising, given some of the
> other papers Hedges has authored or coauthored on the subject of
> molecules-versus-morphology.  Most of the systematics community have come
> around to saying "molecules or morphology?  Yes!", but he is one of those
> who would still favor one over the other.

Which of Hedges' statements is ignorant? 

1. Paleontologists hardly ever look for mammals in C. rocks?

Is there a bias in dollars going to dinosaur research versus
pre-K/T mammal research?  Are there rocks which probably don't contain
dino fossils but might contain mammal fossils?  Are they less likely to be
probed?

2. There was previously not enough convincing evidence for paleontologists
to invest their time searching?

Does the generally held view that pre K/T mammals lack diversity tend to
fulfill itself by discouraging research? 

3. Paleontologists presume that modern aspect species sprang into
existence after the K/T so they don't bother to look?

By the way, I think  Benton's comment about Cretaceous rabbits and
elephants was intended to be ironic, i.e., he seriously doubts
the validity of the molecular evidence.

4. Mammals might turn up in previously overlooked strata?

Ultimately, of course, fossils will arbitrate this particular "molecules
or morphology" argument.  But only if a reasonable amount of effort is
invested.  Has this happened?  From the outside I see two extreme
opinions.  Hedges saying no one has looked, and others 
saying words to the effect of: "We have found all the pre-K/T mammals we
are going to find."  The latter opinion sounds like famous last words.
I respect your opinion--that genetic change doesn't
necessarily create morphological change.  But it is just an hypothesis.
In this case it should enjoy no higher ground than the claim: genetic
change led to morphological but we just havent found the bones yet.  So
just to be on the safe side, shouldn't we look for them?  Unless we
already have, of course.