The question of evolution between vs. within species is outside of my
expertise, but my impression is that this distinction is made by
creationists who are trying to deal with the obvious, and observable-
within -our- lifetime, evolution within species, while denying that it
can produce new species.
Biologists do not treat species as sharp categories, but as generally
non-interbreeding populations. There are many borderline cases. In
other words, species are convenient categories, but we should not make
the error of essentialism, as if they are platonic forms.
Regardless, as several have pointed out recently, evolution is both a
theory and a fact (being careful to note the various uses of the terms),
and this is true both within and between species.
don
Donald McBurney
University of Pittsburgh
[EMAIL PROTECTED] wrote:
>
> From Paul Smith:
>
> >RICHARD PISACRETA wrote:
> >
> >> I must have missed something. Evolution within a species is a
> >>fact. Evolution between species is a theory. I have seen no
> >>definitive proof of one species through intermediate steps
> >>becoming a new species.
> >
> >
> > Again, evolution within a species is the same thing as
> >evolution between species.
>
> I must admit that I have only paid partial attention to this
> thread. Paul's statement caught my eye, however, since I guess I
> had also fallen into the trap of believing the two are different.
> The basis of my belief comes from my understanding of the term
> "species". I had understood it to refer to a group of
> individuals who could potentially interbreed and who were
> reproductively isolated from other groups. To the extent this
> notion is an accurate reflection of the "real world", it would
> seem to suggest that variation within a species and variation
> among species are two different things. The question then
> becomes, have we witnessed the emergence of a new reproductively
> isolated group through evolutionary principles? Having witnessed
> change/evolution within a species seems to me to be different.
> Where am I going wrong?
>
> Buddy Grah
> Dep't of Psychology
> Austin Peay St. Univ.
> Clarksville, TN 37044
