On Wed, 7 Feb 1996, Ronald Orenstein wrote:

> There is a considerable difference between biological species such as these
> flycatchers, which most biologists would, I think, accept as real entities
> having some meaning in nature, and the other heirarchical categories such as
> genus or family.

Quite true, but many people (including a solid majority of biologists,
I'd guess) confuse this with the relationship between species and *higher
taxa* (in the pure sense of clades, branches on the tree), but the
reverse is true here -- we can recognize higher taxa unambiguously,
whereas there can be ambiguity as to where one species (branch tip)
stops and the next begins.

David Wright
dwright at u.washington.edu