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Evolution caricature. Caricature of Charles Robert Darwin's theory of natural selection. It shows a pig transforming into a cow which then transforms into Darwin himself. Darwin (1809-82) studied the differences in closely related but geographically separated species. He proposed that variations in species form arose over time, but only those variations which enhanced a species' chance of survival would be propagated. He first published this concept of natural selection in The Origin of Species (1859). Darwin proposed that humans were related to apes in his Descent of Man (1871). Cartoon by Charles H. Bennett in about 1870.
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