This looks to me more like a particular family of emphases
within neo-Darwinism, rather than the status of the theory
itself. For example, the issue of the unit of selection is
under debate (although it doesn't seem to be as public or
ego-driven).
[Mechanisms:]
[mutations/crossover/etc]
[selection]
> Other high-level neo-Darwinian mechanisms are allopatric,
> parapatric and sympatric speciation, coevolution and
> extinction. Note that examples of sympatric speciation have,
> as far as I am aware, not yet been found in nature.
I'd call these more "descriptions" rather than "mechanisms."
That is, allopatric speciation is something that happens for which
neo-Darwinism tries to find a mechanism. It depends on how
'mechanism' is understood I guess--whether a way in which
evolutionary history has transpired (by speciations of various
sorts) or the processes which drive those events.
["non neo-Darwinian mechanisms"]
[stasis]
[habitat tracking]
[drift]
Again, this seems like a particular slant on the theory to
exclude these. For one thing, selection may be just as
much responsible for stasis and habitat tracking as it
is for speciations. It seems to me that including speciation
as an evolutionary mechanism and excluding stasis leaves
out a very important and interesting facet which neo-Darwinism
has to address--indeed, this has been where Gould and Eldredge
and more have pushed their angle. If you are using 'neo-Darwinian'
to mean specifically a more selectionistic brand of evolutionary
theory, you should know that people who are identified with
that brand also think these things happen, and that drift is
an important component of evolutionary history, they just feel
these things are more boring than not. "Selectionism vs. pluralism"
is the way self-described 'pluralists' refer to this particular
debate. I'm not sure what would rule them out as neo-Darwinists,
though.
-Greg