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!
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…”