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Question on morphological saltation

Hi, and sorry the bother and ignorance, but I have a question for the
evolution-knowing people. I am searching for Recent published
statements against the necessity of morphological gradualism.

I searched in Gould's papers on punctuated equilibria, but he is
mostly interested in phyletic gradualism, and on assessing the problem
if the new varieties gradually replaces the old ones, at a constant
rate, or not. Sadly, I passed my Gould (2002) book to a friend and can
not check for some days.

What I am sarching is, putting an example, not if a white bear variety
gradually replaced the brown bear variety in the North Pole along the
time or whether there was stasis or not. I am searching for a
published statement against the necessity that lots of hues of
progressively lighter fur have to be hypothesized to account for the
appearance of the white bears. And, if you know, of refutations or
attempts of refutation to this.

I think an exaggerated morphological gradualism of this kind is
perhaps not defended by anybody (I did not find citations), for it
would imply infinite intermediate morphologies progressively more
similar to the descendant one (there are infinite hues between brown
and white, and between any colors), and there can not be infinite
individuals in any lapse of time involved in an evolutionary
transformation. This also applies when we see morphology as a dynamic
entity, as a developmental history, and not just an arbitrarily
defined morphology at a stage of their ontogenies. If we define the
dynamical morphology in terms of its developmental history, there
would be no more different developmental histories as there are
individuals, so there would not be possibility of complete
morphological gradualism either.

Note that I am not defending or referring to "hopeful monsters", or
messing into the macroevolutionary debate, we may just be referring to
change in a single body part, in a single respect.