40 Beth Preston
in material and design for centuries or millennia. Lack of variation in components also
occurs in material culture—windows have varied a lot historically in design and construc-
tion, but they standardly have had panes of glass as components. Moreover, much of the
variation that does occur in material culture does not substantially affect its utilitarian
proper function. For example, artifacts often are varied for purely aesthetic reasons (e.g.,
decoration on the handles of tableware) or for reasons of social status (e.g., silver tableware
instead of stainless steel). How much the proper function is affected is a relative matter,
of course. In the case of silver tableware, for instance, there is more upkeep (polishing in
addition to washing) and somewhat greater liability to damage (bent handles, dented
bowls), so what is affected is not the function itself so much as its maintenance. Plastic
tableware, on the other hand, does not work quite as well as metal tableware, especially
for some foods (e.g., steak). Function is clearly somewhat impaired in this case, but not
so much as to make plastic tableware useless, since it works just fi ne for most foods. In
such cases the relative lack of impact on the exercise of the utilitarian proper function of
the artifact typically results in a number of variations persisting indefi nitely alongside one
another rather than in one variation winning out and the others disappearing. Thus in
material culture, even when there is considerable variation, there is often a lack of suffi cient
variation relative to the function under consideration, and the requisite process of selection
over alternatives is stymied.
Sometimes even when variations do affect function, persistence or disappearance of
variants is conditional upon extrafunctional features. Plastic tableware persists alongside
metal tableware not only because it still functions relatively well for eating but because it
has other features (cheapness, disposability) that endear it to consumers. This points to
the operation of a cultural analogue of genetic drift. When a variation persists or disap-
pears, the reasons do not necessarily have anything to do with how well it fulfi lled its
erstwhile function. Perhaps it actually worked better than all the competing variations, but
the company was poorly managed and went under, or it ran afoul of Microsoft, or the
advertising or distribution were not adequate, or the colors were unfashionable, or what-
ever. Or perhaps, like plastic tableware, it does not work as well, but is favored by certain
human populations for other reasons, and thus persists alongside the more effi ciently
functioning variants. This phenomenon bears some resemblance to genetic drift in biology,
where the frequency of genes in a population can change for reasons extraneous to natural
selection, like natural disasters that randomly wipe out members of a population with no
regard to their fi tness, or locally favorable conditions in which otherwise nonadaptive
features can persist.
Finally, Schwartz’s second problem—ambiguous variation—is certainly imaginable.
Suppose a basket originally made by a Native American group for winnowing grain
becomes popular in the tourist trade. And suppose some variation makes it both better for
winnowing and more attractive to tourists. But suppose that the need for disposable cash
is what is driving the reproduction of these baskets at the moment. Then we want to say