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re:herbs to carns (umpity ump)



>     I nominate the rat.
>
>
>     -Betty Cunningham

        Well, nice try. Your average rat is a generalist omnivore as I
understand it. Truthfully, I don't think that there are any great examples
of the carn-herb transition, except maybe in invertebrates. Some of my
recent discussions with digestive physiologists and mammalogists have
illuminated me...
        It seems that the generally accepted reason that there are few good
carn-herb (or herb-carn) direct transitions (without an intermediate
omnivorous condition) is that it's tough either way. A gross simplification
follows. To go carn-herb, you need an enlarged, elaborated gut to process
all of that bulk matter, plus bacterial symbionts, specialized dentition
(it helps), modified enzymes, etc. The other way, you don't have the
digestive problems as much (but have to get used to easily digested meat
first), but you do need specialized dentition and other morphological
modifications, assuming you're going to be a strict, predatory carnivore.
Overall (and this is really stretching things), it might be easier to go
herb-carn. An omnivorous halfway point is the usual case, though. Nuff
said; I won't drag out this discussion further if people think it's not
dino-related enough. Heck, it was fun.

                        John R. Hutchinson
                  Evolving Evolutionary Biologist
                 Department of Integrative Biology
                University of California - Berkeley
                        Berkeley, CA 94720
                          (510) 643-2109

        "Thus, the student of adaptation has to sail a perilous course
between a pseudoexplanatory reductionist atomism and stultifying
nonexplanatory holism."         --E. Mayr, "How to carry out the
adaptationist program?"