Documenting plant domestication: The consilience of biological and archaeological approaches
Bruce D. Smith*
+ Author Affiliations
Archaeobiology Program, Department of Anthropology, National Museum of Natural History, Smithsonian Institution, Washington, DC 20560
For more than a million years our distant ancestors were hunterâ€“gatherers, relying exclusively on the gathering of wild plants and the hunting of wild animals for their food. Then, between 10,000 and 5,000 years ago, dramatic changes took place in this longstanding way of life, as human societies in more than a half dozen regions of the world, including Mexico, independently domesticated a variety of different plants and animals (1, 2). These early domesticates, and the agricultural economies subsequently based on them, marked a major turning point in the history of the earth and our species, in that they formed the lever with which humans have relentlessly transformed the earth and its terrestrial ecosystems. Not surprisingly, this â€œNeolithic Revolutionâ€ has attracted increasing attention from both biologists and archaeologists in the more than five decades that have passed since the pioneering field research on agricultural origins by Vavilov, Braidwood, and MacNeish (1). No longer open to easy and universal explanation as a rapid and straightforward transition between adaptational steady states, the developmental shift from hunting and gathering to agriculture has in the past several decades blossomed out into a set of long-unfolding and fascinatingly complex, regional scale developmental puzzles. The most dramatic recent advances in understanding these diverse and extended regional transformations center on documenting the domestication of individual species and involve a consilience and cross-illumination of biological and archaeological approaches. In this issue of PNAS, two articles provide a welcome new addition in this area of research, while also underscoring how much is still to be learned about the initial domestication of maize, and more generally, about agricultural origins in Mexico. Piperno and Flannery (3) report on the oldest maize (Zea mays ssp. mays) cobs yet recovered from Mexico, describing their archaeological context and reporting direct accelerator mass spectrometer (AMS) radiocarbon age determinations. In a companion piece, Benz (4) provides a detailed description of the cobs and documents initial morphological changes associated with domestication, including the development of a nonbrittle, rigid rachis and an associated loss of natural disarticulation and seed dispersal.
Copyright Â©2012 by the National Academy of Sciences