[Taxacom] nucler vs plastid trees

[John Grehan]

My thanks for all the comments and responses (some off list). I get the
impression that its a bit of an unresolved problem. However, its does not
seem to be an impediment to the widespread use of molecular analyses (and
its virtual supplanting of morphology). I do not have the level of
comprehension to make any judgment bout the incongruence. From what some
have indicated, the incongruence problem might even render molecular trees
uninformative. I certainly have no argument with the issue of morphology
coding genetic traits as I have argued for over a decade for the orangutan
relationship.

My present focus is in the sue of molecular trees for biogeographic
reconstruction since that is pretty much all that is available to me.
However it is good to have some idea of how others view the nuclear and
plastid (or mitochondrial) incongruence. Theoretical questions aside, the
molecular trees repeatedly show extensive clade allopatry at all levels or
organization, as was extensively demonstrated by Heads (2012, 2014). The
bizarre aspect of this allopatry is that it is almost always attributed to
grand global migrations as if the taxa all new where to go in order to
occupy different localities (a sort of global musical chairs, where the odd
taxon out - the one who does not find a 'chair' - becomes extinct).

John Grehan