L.A. Moran wrote:
> >Among trained experts, the
> >word "primitive" means "retaining an ancestral state". The
> >contrary of "primitive" is "derived". It is a straightforward
> >matter to apply these terms to individual characters in cases
> >where ancestral states can be inferred.
> I appreciate the point that you are trying to make but perhaps it would be
> best to remember the context. Someone wanted to knw if there were any
> organisms that were more primitive than Drosphila but less primitive than
> C. elegans. Why? Because he was hoping to isolate a C. elegans gene using
> a human probe and was looking for an "intermediate" model organism. Do you
> think that this is a reasonable experiment? Is it consistant with your
> understanding of evolution. (I sure hope not or I have seriously misjudged
> you!) (-:
Yes, I didn't mean to deny the possibility that the question was
a bit absurd (I thought that this was implicit at the beginning
of my statement). More generally, we could probably all dispense
immediately, today, with using the words "primitive" and "derived"
(or its confusing semi-synonym, "advanced") *in reference to
species or higher taxa* and biology would be none the
worse for it. If I were the editor of an evolution journal, I
would explicitly forbid this usage in the instructions to authors,
because there is such an extraordinary tendency toward abuse
(a bit like the words "novel" and "striking" in molecular biology
journals). Of course we would want to retain these useful
terms for referring to individual character states.
I only wanted to warn that the history of evolutionary
biology (maybe other sciences too) is peppered with instances
in which the rejection of a false doctrine led to over-generalizations
that became false doctrines themselves and inhibited research
in interesting directions. An example would be the over-heated
rejection of Lamarckism, orthogenesis and mutationism, which
leads to blanket statements about mutation being "random" (in
spite of the obvious evidence that mutation is non-random in
many ways, including its relationship to fitness-- there
is usually a bias in favor of fitness-decreasing mutations
over fitness-increasing ones, as everyone knows) and "spontaneous"
(in spite of other observations to the contrary).
Department of Biochemistry
Halifax, Nova Scotia B3H 4H7 CANADA
(email) arlin at is.dal.ca