species concepts

[tom dibenedetto]

On Thu, 11 Jul 1996, ROGER HYAM wrote:
> People are endlessly bolting biological explanations on to
> Aristotelian logic instead of the other way round. We all want there
> to be species of genera (i.e. kinds of things) out there because that
> is the way our language (and so our minds?) work.

I would rather say that people are  *sometimes* bolting biological
explanations onto empirically discovered patterns, which is exactly how
it should be.
Are you claiming that the distinctions we see in nature are purely
artifactual, a result of peculiarities of our minds, hence with no
objective reality? I would strongly disagree.
>
> A species is, in fact, a convenient administrative unit and nothing
> more.

This I also disagree with. Thee are very real differences between oak
trees and salmon, and the recognition of these differences is not merely
a human bias. The same holds for the differences we percieve between pink
salmon and Atlantic salmon.

> Although the term is sometimes used of groups that may have some
> biological significance there is no reason why the whole of
> diversity should be divisible into mutually exclusive species. (the
> cook cutter theory)

Except that is what we have found! Nothing is "necessary". The role of
theroy is to explain the evidence.

Tom diBenedetto
Fish Division
University of Michigan Museum of Zoology