[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re: Question on morphological saltation

Thanks for the responses. I am not speaking in population terms when
speaking of morphological saltation, this term is used by me (perhaps
incorrectly) in a sense different from that of punctuated equilibrium.
I am not sure if the gradualism in morphological change I referred to
is necessarily related to the observed variation in one moment of the
population history either. I was referring to a morphological
gradualism in terms of the old-fashioned orthogenetic series of
horses, carried to an infinitum of intermediate forms (which I suppose
nobody defended), without referring explicitly to them (and only for
simplicity neglecting ramifications).

For example, suppose a mutation created a white bear from brown
parents. The white variety then progressively displaced the old
variety from the population until reaching fixation. That is a gradual
replacement. Yet, there was a change from brown fur to white fur, and
not between all infinite hues of brown each time lighter. This I
called "morphological saltation", because of not knowing another term.
This, I suppose, can also apply to the trait, say, development of
"process x", without having to hypothesize infinite stages of the
developmental histories for the process.