1492 and the loss of amazonian crop genetic resources. I. The relation between domestication and human population decline

There may have been 4–5 million people in Amazonia at the time of European contact. These people cultivated or managed at least 138 plant species in 1492. Many of these crop genetic resources were human artifacts that required human intervention for their maintenance, i.e., they were in an advanced state of domestication. Consequently, there was a relationship between the decline of Amazonian Amerindian populations and the loss of their crop genetic heritage after contact. This relationship was influenced by the crop’s degree of domestication, its life history, the degree of landscape domestication where it was grown, the number of human societies that used it, and its importance to these societies. Amazonian crop genetic erosion probably reflects an order of magnitude loss and the losses continue today. Dedicated to the memory of Paulo Sodero Martins, 1941–1997, fellow student, researcher and professor of South American crop domestication, origins and biogeography.