Afarensis mentions a forthcoming paper by Lyman, VanPool & O’Brien that will be published in the Journal of Archaeological Science. They’re looking at change in arrowhead types over time from an evolutionary perspective.
“…there is evidence of an initial burst of variation in projectile points at the time bow-and-arrow technology was introduced and that prehistoric artisans experimentally sought arrow points that worked effectively. Following that initial burst, less-effective projectile models were discarded, causing archaeologists to see a reduction in variation.”
This sounds like complete bollocks to me. If pre-scientific humans had been technological optimisers, then all arrowheads globally would fall into a small number of standardised task-specific types. Culture does not change through time in a manner like that of biology, because cultural selection is largely irrational. Most of what people do is white noise from an evolutionary perspective. Null mutations.
Today I paint my face red for the ritual dance. Twenty years from now my daughter will paint hers blue. It is deeply significant from a cultural point of view, but completely irrelevant from an evolutionary one. Today I will make arrowheads 15% longer than those I made last year. I have no idea what the practical consequences of this decision, if any, will be.
What those ancient archers are likely to have done is make good-enough arrowheads. Every generation produced variations on this good-enough template, and those variations are likely to have been determined by sheer cultural capriciousness. Ancient hunters did not have their act together. (Nor do modern hunters, farmers, traders, hair dressers.) They did not have a good large-scale pragmatic overview of what they were doing, and indeed they would not have acted completely rationally even if they did have access to such an overview.
Looking at arrowhead diversity and concluding that decreasing variability is the result of technological optimisation, you’re just telling a just-so-story. In order to say that, you need to demonstrate that the later types are in fact better tech than the earlier ones. In all likelihood, they’re neither significantly better nor worse. They’re just different.
People bungle forward in a good-enough way, guided by superstitions and half-formed ideas of what the world is like. Some bungle in a non-good-enough way, and starve, or have their culture obliterated by nuclear war or global warming. Archaeology and anthropology is the study of the cultural specifics of this bungling.
Update 19 June: The many passionate and well-phrased responses to this entry make me I wonder if the idea of the Noble Savage is still kicking around here. Do people want our forebears to have been smart and rational, in tune with their environment? I think culture is generally a disaster for the environment. The only reason that our forebears’ societies survived long-term was their high infant mortality. They wanted to do things that would have wrecked their habitat, but their low population densities prevented them.