INDEPENDENT INVENTIONISM AND RECENT GENETIC-EVIDENCE ON PLANT DOMESTICATION

The recent accumulation of cytogenetic evidence on the ancestry of the earliest domesticated plants provides an empirical test of the relative importance of independent invention and diffusion in the origin and spread of agriculture. The most parsimonious interpretation of the data is that plant species were domesticated no more than a few times, and perhaps only once, in the Near East and Mexico. Multiple domestications of species may have taken place in the central Andes, but it is impossible to say whether any such cases were truly independent, because of the scantiness of the archaeological as well as botanical record. Evidence from other agricultural centers is limited, and does not negate the conclusion that multiple independent domestications within regions were rare, while domestications of the same species or genus in different regions did not occur as frequently as some authorities have claimed. The prevailing tendency to interpret archaeological sequences as almost entirely the result of local in situ development is not entirely in accord with theory, nor with the genetic evidence summarized here.