ABSTRACT
The pattern of crop diversity in the fields of the developing world has changed fundamentally over the past 200 years with the intensification and commercialization of agriculture. The yield enhancing seed types enabled the intensification of agriculture in areas of the world with high population densities. Intensification of agriculture refers to the increase in output per unit of land used in production, or land productivity. Population densities, expressed as the ratio of labor to land, explain much about where and under which conditions this process has occurred. Agricultural intensification influences the extent of crop diversity in two ways: first, through changes in land use patterns, and second, through crop choice changes. The change in the crop genetic landscape from predominantly traditional to largely modern patterns of genetic variation occurred over the past 200 years and at an accelerated rate since the 1960s with the advent of the Green Revolution.
