Anthropogenic Seed Dispersal: Rethinking the Origins of Plant Domestication.

It is well documented that ancient sickle harvesting led to tough rachises, but the other seed dispersal properties in crop progenitors are rarely discussed. The first steps toward domestication are evolutionary responses for the recruitment of humans as dispersers. Seed dispersal-based mutualism evolved from heavy human herbivory or seed predation. Plants that evolved traits to support human-mediated seed dispersal express greater fitness in increasingly anthropogenic ecosystems. The loss of dormancy, reduction in seed coat thickness, increased seed size, pericarp density, and sugar concentration all led to more-focused seed dispersal through seed saving and sowing. Some of the earliest plants to evolve domestication traits had weak seed dispersal processes in the wild, often due to the extinction of animal dispersers or short-distance mechanical dispersal.