cladism's greatest weakness

[Richard Zander]

----- Original Message -----
>for the
> benefit of any of the rest of you that might be "muddy" on this point, a
> species and all its descendents constitute a clade. If species are real,
> and if evolution happens, clades are real, not arbitrary.

This is yet another example of the forever-ongoing battle of realists (who
assume that the world is observer-independent and knowledge is objective and
absolute), and pragmatists (who ignore the question of observer-independence
and act in ways that maximize the usefulness of information, no matter how
such information is generated). Check out a Philosophy of Science web site
for more information.

My problem with realists is that their take on reality is what must really
be, but just like everybody else's take on reality it's full of
misapprehensions, confusion, half-truths and circularity. Sure, the pursuit
of knowledge is not especially enhanced by negativism, but reality is a
shared Gray Area that requires a measure of pragmatism to give many people
having diverse philosophical positions confidence in accepting  new
knowledge as important in their lives (and research).

Species at least exist as tools, and are useful even though their
circumscriptions are labile over time as new information presents itself.
Clades at least exist as tools. No, ancestral species do not have to
disappear (it is not a convention), but given the data sets, we seldom find
a sister branch (as a computational tool, mind you) with no syn- or
autapomorphies (so practically speaking ancestors disappear even if the
speciation event that destroys them is just gradual change).

Concepts are real. Let's agree on the minimum reality that "things out
there" are at least valuable conceptual tools. Then examine what you want to
do with these tools.


Richard H. Zander, Curator of Botany
Buffalo Museum of Science
1020 Humboldt Pkwy
Buffalo, NY 14211 USA
email: rzander at sciencebuff.org
voice: 716-895-5200 x 351