Thor Hanson, author of The Triumph of Seeds was doing fieldwork in Central America when he became fascinated by the seeds of a giant rainforest tree known as the almendro. Hard as rock, impervious to hammer blows or chisels, they set him to wondering how seeds are dispersed and how they have shaped human history.

Speaking from his home in Washington state, where he is a conservation biologist, he explains how grains and revolution often go hand in hand; why Ugandans throw millet over newly married couples; why seeds are the frackers’ best friends; and why the future of seeds is such a hot button issue.

[Laughs] I had chosen to study this fascinating rainforest tree in Central America, the