The Isthmus of Panama as a Crossroad for Prehistoric Migration of Domesticated Plants

For thousands of years, Indian tribes have gathered, selected, domesticated and spread useful plants over the whole American continent while mostly practicing shifting forms of horti-agriculture. It has been argued that origin and domestication of New World crops could be traced back to essentially two independent, narrowly circumscribed core regions, (i.e. Vavilov's genecentres) one in the highlands of Mexico and the other in the Andes of Peru. Those alleged centers of origin and genetic diversity have been synchronized with the main cradles of American agriculture. Based on long periods of research work in South America, we disagree with this opinion which is maintained primarily by anthropologists, sociologists and ethnologists. Except for marginal desert and mountain environments, there are no real biogeographical restrictions for plant domestication. Apparent geographical barriers, like the Darien gap, did not represent insurmountable hindrances for the diffusion and migration of useful species in the hands of indigenous peoples.