I realize that this may be taking the discussion far afield from
strict molecular biology, but lately I have been participating in many
discussions about species concepts and have come up with two ideas I
would like to put out for evaluation.
The first is that I would like to express solidarity with Endler's
view that we utilize more than one species concept (this is expressed
in chapter 25 of the volume he edited entitled "Speciation and its
consequences".
It seems only logical that not one tool will serve to discern all of
the biotic diversity that exists. Whether one uses a biological
species concept (probably most applicable to ornithologists, since
they are the ones who had initially proposed it), phylogenetic species
concept (most applicable to paleontologists), recognition species
concept (most applicable to many behavioral ecologists?), or some of
the other myriad of ideas seems to me to be dictated by the type of
data that one can wrest from the organism.
As a result, many of these different species concepts have, at their
root differences in the manner with which "species" are discerned from
ea sequencing, morphology, biogeography, behavior, etc. All of these
concepts should of course use cladistics to transform the data into
(hopefully) robust evolutionary histories.
Secondly I would like to propose the idea that rates of speciation may
be site-dependent. Geographical differences also dictate
environmental differences which would in turn dictate different
selection pressures. The idea that one population will diverge or
speciate at the same rate panglobally is absurd, the microclimatic
circumstances must be taken into consideration when speculating about
speciation rates. Mitochondrial DNA work may lead to
misinterpretations of the "truth", since it assumes constant rates of
speciation (ie: gradualism) and uniform speciation rates. [I am not
disparaging mDNA work, only its universal application. I am sure that
organisms that have been in a relatively constant environment would be
most effectively analyzed using mDNA]
Anyway its something to think about.
--
Jim Danoff-Burg (Snow Museum, Univ. of Kansas, Lawrence, KS 66045)
Bitnet: KUENTO at UKANVAX
