Human culture subject to natural selection, Stanford study shows

Functional traits (top) for Polynesian canoes may affect whether a voyage for fishing, warfare or colonization succeeds. In box A, a detail of outrigger attachments on a Tahitian canoe; in B, a Samoan canoe “sewn” together with sennit (coconut fiber cord); in C, a canoe from Manihiki showing a pattern of sewn washstrake pieces. Symbolic traits, bottom, for Polynesian canoes presumably have no differential effect on survival from group to group. In box A, a painted paddle from Rapanui (Easter Island) alongside a face tattoo from the Marquesas Islands; in B, a canoe from Manihiki decorated with inlaid shell; in C, a carved figurehead on Maori war canoe.