From: John Wilkins (j.wilkins1@uq.edu.au)
Date: Thu 02 Jun 2005 - 00:35:10 GMT
On 02/06/2005, at 3:47 AM, Dace wrote:
>> From: John Wilkins <j.wilkins1@uq.edu.au>
>>
>> A species is just some handy tag we assign to organisms to help
>> communication between scientists. I have some sympathy for it,
>> although I reject it.
>>
>
> Certainly the boundaries between species are fuzzy. Darwin noted
> this in
> support of evolution. After all, if the species had come about
> through
> special creation, the boundaries between them would be well-defined
> and
> absolute. But that doesn't mean such boundaries are merely conceptual
> conveniences. We are not, after all, bats or worms or moonflowers.
>
> I think you're stuck in a false dilemma. The concept of species is
> not a
> choice between absolute or nothing, realist or nominalist. If
> there's one
> thing that distinguishes life from nonlife it's the property of
> vagueness or
> fuzziness. There are no hard and fast distinctions in biology of
> any kind,
> not just in regard to species. Everything bleeds into everything
> else.
> Every cell type in the body is just a modification of an original
> type,
> every pattern of leaf or bone a modification of a basic form. Yet
> each
> class still retains its identity. Without a sense of vagueness, of
> ambiguity and overlap, of sameness coexisting with difference,
> there's no
> real comprehension of life. The fetish among biologists for
> exactitude,
> which was inherited from the physical sciences, is a major
> roadblock in the
> development of an appropriate theoretical model for the life sciences.
You are mislocating the blame, and at the same time doing a
historical injustice.
Essentialism is due to the logic of Aristotelian categories and
taxonomy. It was rarely employed by actual science, though, until the
19th century. Darwin was one of the people who enabled the so-called
Strickland Rules for taxonomy. The modern fetish against essentialism
is due to Popper's works, and the modern fetish *for* it is due to
non-biologically informed philosophers such as Putnam and Kripke.
But the categorial, or taxonomic, classification that existed prior
to this in, for instance, John Ray, Caspar Bauhin and Conrad Gesner
(and some latecomer name Linne), is merely a diagnostic essentialism.
They all knew that organisms varied, but they needed a character or
more that would enable a medico to identify the same plant, or a
field observer to identify the same bird. This was harmless.
The notion that evolution requires either a denial of the reality of
species, or that the concept means species are in principle
indefineable is due not to Darwin (who had not trouble being a
taxonomic essentialist) but to Lamarck, and in particular Lyell's and
Cuvier's reactions to Lamarck. *That* was when species were insisted
upon being sharply demarcated. But for the entirety of prior western
history of biology - and believe me I've looked - species were never
expected to be sharply demarcated.
The claim that species shade from one to another was due to the
Aristotle-derived great chain of being. All Lamarck did with it was
make it a temporal sequence.
-- John S. Wilkins, Postdoctoral Research Fellow, Biohumanities Project University of Queensland - Blog: evolvethought.blogspot.com "Darwin's theory has no more to do with philosophy than any other hypothesis in natural science." Tractatus 4.1122 =============================================================== This was distributed via the memetics list associated with the Journal of Memetics - Evolutionary Models of Information Transmission For information about the journal and the list (e.g. unsubscribing) see: http://www.cpm.mmu.ac.uk/jom-emit
This archive was generated by hypermail 2.1.5 : Thu 02 Jun 2005 - 00:52:00 GMT