[Taxacom] invisible evolution/paraphyly

[Rob Smissen]

"Maybe there's a problem with species definitions, Curtis. Could you
tell
us, in short, what the difference is between paraphyletic species and
paraphyletic higher taxa"

Ill take an uninvited stab at this for the sake of argument,

Paraphyletic species exist because sexually reproducing species are
composed of individuals whose intermingled pedigrees cannot often be
meaningfully summerised by abstracted dichotomising tree diagrams

while

Paraphyletic higher taxa can be identified when sufficient
allele/population/species extinction has taken place to allow a
predictive abstraction of organismal pedigrees to a dichotomising tree
.... provided one is not worried about all those extinct
alleles/organisms/populations/species that if sampled would render ones
parsimony/likelihood/baysian analysis completely devoid of statistically
supported branches.

Turning the former into the latter requires only waiting for extinction
events to accumulate, or taking matters into ones own hands and
overcollecting the difficult populations ;)

Having spent too much time in the lab and not enough in a herbarium
lately, it seems to me that monophyletic really means monophyletic at
some fraction of loci (going back to Maddison 1996), and is starting to
seem rather quantitative, and, dare I say it, phenetic. I'm sure I have
a few reptile (or is that non-amniote reptile) genes knocking around in
the back of the genome somewhere ...

I'm also starting to find "population" rather trickier to apply in the
real world than we systematists tend to pretend.

Please don't ask me to define an individual.

And for now my head is stuck in the sand when it comes to allelic
recombination.

cheers
Rob
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