Re: Last Supper Hypothesis

Gerrit Hanenburg (ghanenbu@inter.nl.net)
Sat, 19 Aug 1995 19:35:50 GMT

"Dr. Marion" <lrmarion@email.unc.edu> wrote:

>My posting concerns research involving dental mirowear. In general there
>are atleast two ways to compare microwear in different species. One is
>to compare features observed with the SEM, such as pits and striations,
>for directionality and density. The problem with such an approach is
>that repeated wear obliterates details f previous wear patterns. This is
>often referred to as the "Last Supper Hypothesis." Many proponents to
>this feel that wear observed on a tooth will only contain clear evidence
>of the last meal that tooth participated in masticating.

>What are your thoughts on this?

My thoughts:
The last meal will obliterate some of the wear patterns caused by previous
ones.The result will be overprojection leading to a complex mixture of
patterns caused by several consecutive meals.(comparable to the
overprojection of cutmarks on bone caused by carnivore teeth and stone
artifacts which have led to the conclusion that hominids were scavengers)
I don't think the information of previous meals is completely lost (up to a
certain limit of course) but it maybe more difficult to interpret.
If the species had a rather stable diet the different patterns will resemble
each other and so some loss of information of part of the previous patterns
will be less of a problem. But if it had a rather variable diet the problem
will be a bias towards wear caused by tough gritty material,leading to the
conclusion the it ate tough gritty food while in fact it also may have used
large quantities of softer material,as might have been the case in
Paranthropus.I think part of the solution is to compare the wear pattern on
the teeth of different individuals of the same species.This should give you a
reasonably accurate image of the overall diet of the species.(Assuming that
the chances of the last meal being the same in all individuals is rather
small)

Gerrit.