[Taxacom] Taxacom Digest, Vol 43, Issue 14

[Sergio Vargas]

Hi there,

>Pretending to use species concepts??  That seems a bit judgmental.

my experience perhaps... I have worked with taxonomists for a while
now and the question what species concept do you use? seems to have a
purely cosmetic answer in most cases.

> Whether a given "species concept" defines "real species" and/or just an explanatory hypothesis that approximates something that may be real or not, I believe that it ultimately depends on how fuzzy
> the given species is, which often tends to vary greatly from one phylum to another.

the species it self is the explanatory hypothesis sensu Fitzhugh. When
I describe a species, what I am actually doing is postulating the
existence of a speciation event leading to the segregation of the
ancestral population into the newly recognized species and its sister
clade. I postulate this because I judge the new specimens belong to a
different tokogenetic network not previously discovered. That's why
species concepts usually don't work because species are hypothesis
trying to explain the variation in the characters observed in a number
of specimens.

> Is there any reason to assume that a "unified species concept" is superior to multiple species concepts (largely varying from group to  group)?  What works for bacteria is largely irrelevant for Metazoa or
> Metaphyta.  Not surprisingly, the author of the "unified species concept" is also a proponent of Phylocode.  In both cases, the results (both nomenclaturally and more broadly systematically) seem to me to > be simplistic generalizations that do more harm than good in the long run.

That's precisely the point. Most species concepts are insufficient,
and in the long run there is not a superior one. However, if one
regard the species it self as a hypothesis, it is possible to
understand what Metazoan or  bateria species refer to. That's what's
interesting about Fitzhugh "species are explanatory hypotheses"
contribution.

> I say, "Viva la difference"!!! Reductionism and generalizations often run into problems when applied beyond the limits within which they have been shown to definitely apply.  In other words, extrapolation > has its limits, and is dangerous when overly stretched.

indeed, different organisms need different explanatory hypothesis.

> Perhaps that is why the arguments about the "reality" of species tends to be so controversial. Sometimes it depends on what organisms one is
> studying.  Of course, it is further complicated by the paraphyly issue, the  philosophical divide between those who  disagree about whether the paraphyly of species (and higher taxa) is useful and/or
> natural.  The paraphyly issue is the broadest and most divisive issue that results in a lot of other lesser controversies (one of which is species concepts, and whether a "unified species concept" is just a
> pipe dream with no logical basis).

difficult isn't!

cheers

sergio

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yo
Sent from Munich, BY, Germany