Darwin’s first sketch of the tree of life from one origin. Note the cross-bars for extinction — and that change is not conceived with some direction-as-progress. And notice Darwin’s simple words introducing the sketch, “I think…”
Darwin's finches with their food! Large ground finch with prickly pear cactus, medium ground finch with tree buds and small seeds, and tool-using woodpecker finch with long horned beetle. Thanks Nathaniel!