Did ear­ly hominins evolve on the savan­nah? Almost any­one who reads works on pale­oan­thro­pol­o­gy would say “yes.” I would like to explain why I’m tempt­ed to say “no.”

A long time ago, I was chat­ting with an ornithol­o­gist. We were dis­cussing the Cana­di­an province of Saskatchewan, the south­ern third of which con­sists of the clas­sic North Amer­i­can prairie land­scape. I casu­al­ly referred to some “prairie birds”, includ­ing among them the wil­lett and the killdeer. My friend cor­rect­ed me. “Those aren’t prairie birds at all,” he said. “They live on the river­banks. That’s a total­ly dif­fer­ent ecosys­tem. It doesn’t mat­ter that it’s only a few hun­dred yards wide and six hun­dred miles long, it’s not the prairie. Dif­fer­ent plants and ani­mals, liv­ing a dif­fer­ent lifestyle.” This was some­thing I hadn’t grasped. The prairies of Saskatchewan sup­port species like the lark bunting, the bobolink, the west­ern mead­owlark, and the sharp-tailed grouse, which all nest, feed and frol­ic on the grass­lands, and are all bona fide “prairie birds”. Fur­ther to the north, in the great Cana­di­an for­est, you will find wood­land species like the black­poll and Ten­nessee war­bler, the pine siskin, and the nuthatch. But the wil­lett and the killdeer live and work in a ripar­i­an niche, the com­plex ecosys­tem of river­banks and lake­sides, which is fun­da­men­tal­ly dif­fer­ent from the grass­lands that sur­round them. Read more »