species concepts

[ROGER HYAM]

Dear Folks

There are no absolutes in taxonomy. Rank is relative. Thus one
species (or genus or family...) can not be compared with another in
absolute terms. A species can only be compared vertically in the
hierarchy. The chairman of IBM is the same rank as the chairman of my
local drinking club, that doesn't make them comparable in absolute
terms. Their ranking just has the same title.

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.

A species is, in fact, a convenient administrative unit and nothing
more. 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)

I hope that I have made myself clear. This kind of thing usually
requires much arm waving and shouting and that is difficult in a text
base medium.

Cheers,

Roger.