[Taxacom] Evolutionary misconceptions (mother-daughter pairs)

[Kenneth Kinman]

Hi All,
      I would agree with Richard Pyle's observations about fuzziness of
species boundaries, etc.  He is probably also right that the argument
between anagenesis vs. cladogenesis is most likely to yield "no winners
and plenty of losers".  When it comes to speciation, I would rather
stick with terms that are less subject to controversy (sympatric,
allopatric, etc.).              
      As for mother-daughter species pairs, I think Curtis is unwise in
claiming that they are rare (or don't exist).  I'm sure many would
regard a diploid species giving rise to a tetraploid species as a
mother-daughter pair, not a sister-sister pair.  Same with a mother
species giving rise to allopatric daughter species (especially tiny
initial populations on islands).  The point is that the mother species
can easily remain static, while the daughter species alone diverges.
The only reason not to label them mother-daughter species pairs is that
it sort of has a hint of paraphyly which the sister-sister label does
not have.  Those who have been taught that paraphyly is bad or unnatural
would thus tend to shy away from using the mother-daughter label even if
it might be more appropriate.
             ---------Ken Kinman