The PSC has arisen largely in opposition to the Biological Species Concept
(BSC), the central concept of which is 'Species are groups of interbreeding
natural populations that are reproductively isolated from other such
groups.' (Mayr 1996: 263) The application of the emphasis on interbreeding
can be most easily studied with sympatric populations, the so-called
Non-Dimensional BSC. But questions arise in relation to allopatric
populations. This led to the Multidimensional BSC (Mayr 1996), according to
which species are often composed of local or temporarily circumscribed
populations which differ slightly from each other. Such populations, when
they are considered to be conspecific, are combined into a polytypic
species. Mayr (1996: 272) recognised: 'The major species problem in species
level taxonomy is to decide which local populations to combine into
polytypic species. Since this decision is based on inference, it is always
somewhat uncertain.'
We suspect that the main factor driving the splitting of albatross species
in Robertson and Nunn (1998) was the fact that conservation legislation in
many countries considers only species as worthy of protection, and not
subspecies. We sympathise with this strategy. Conservation legislation is
flawed. The entities that become extinct are often genetic lineages (or
populations) rather than species, except of course where a species consists
of a single population. And we endorse the proposal of Schodde and Mason
(1999) for the use of a distinct term, 'ultrataxon', to refer to
monophyletic species plus the subspecies of polytypic species. But we agree
with Schodde and Mason (1999) that the inadequacy of conservation
legislation is not an adequate reason to change one's considered scientific
position in relation to the question of species.
John Penhallurick
86 Bingley Crescent
FRASER, A.C.T. 2615
AUSTRALIA
S 35° 11' 40.2"
E 149° 03' 26.2"
Home Telephone: (61 2) 6258 8428
Mobile 0408 585428
Please visit my website
http://worldbirdinfo.net
==============================www.birding-aus.org
birding-aus.blogspot.com
To unsubscribe from this mailing list,
send the message:
unsubscribe
(in the body of the message, with no Subject line)
to:
=============================
|
