BSC

[Bill Shear]

>On Thu, 11 Nov 1999, Curtis Clark wrote:
>
>> I think of the BSC as the "Bogus Species Concept"; there is a certain
>> elegance to the basic idea, but in practice the failure to realize that the
>> ability to interbreed does not correlate with gene flow renders the concept
>> untenable even with vertebrates, much less with plants and a whole lot of
>> other "ill-behaved" organisms.
>
>The BSC also requires, in addition to ability to interbreed, the
>production of fertile offspring which themselves have the ability to
>interbreed; in addition, this "gene pool" must retain its identity with
>respect to other gene pools.  That doesn't rule out gene flow between
>species, but the production of hybrids should not play any significant
>role in the evolutionary fate of either species.


This is an all-too-common misunderstanding of the BSC.  The question is not
an "ability to interbreed," but the presence of reproductive isolation
between populations.  In other words, being a species is a relationship
with other populations, not an intrinsic property of the population itself.
Similarly, if we do not know of the existance of your siblings, we cannot
call you a brother or a sister.  Those two terms denote a relationship, not
an intrinsic property of you yourself.  BSC defines a species not as a
freely interbreeding population, but as a population that is REPRODUCTIVELY
ISOLATED from other such populations.

Do all botanists misunderstand the BSC to this extent?  If that is the
case, then their dissatisfaction with it should be easily put aside (just
kidding, I know there are many other difficulties in applying the BSC to
plant taxa).

Bill Shear
Department of Biology
Hampden-Sydney College
Hampden-Sydney VA 23943
(804)223-6172
FAX (804)223-6374
email<bills at hsc.edu>