I've done a whole series of stories set in an alternate world where Homo erectus settled the Americas several hundred thousand years ago but the Indians never made it across the Siberian land-bridge (these stories are collected as A Different Flesh, Congdon & Weed, 1988). The presence of these subhumans—"sims"—and the Indians' absence would have made a profound difference in the way North and South America were settled by European colonists . . . and the way people looked at our place in nature. I've chosen this particular story because of the issues it raises—and because writing pastiche is so much fun.