At 1:51 AM -0600 8/20/99, [EMAIL PROTECTED] wrote:
>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?
As indicated earlier, the designation of a particular group as a 'species'
is somewhat arbitrary. For instance, some biologists regard humans and
chimpanzees as members of the same species (see Jared Diamond's _The Third
Chimpanzee_). I'm not aware that the possibility of interbreeding has ever
been tested.
'Reproductive isolation' may be geographic rather than physiological (genetic).
Second question: how do you define 'witnessed'?
If you mean 'observed with one's own senses', then much of science depends
on evidence that has not been witnessed.
I did cite some examples in an earlier post of evolution of new species
within recorded human history.
<http://www.talkorigins.org/origins/faqs-qa.html>
and
<http://www.natcenscied.org/>
for much more specific documentation.
* PAUL K. BRANDON [EMAIL PROTECTED] *
* Psychology Department 507-389-6217 *
* "The University formerly known as Mankato State" *
* http://www.mankato.msus.edu/dept/psych/welcome.html *
