gh which evolution takes place. It was no longer quite sufficient to say that God, or the vital force, mystically drove life ever-upward. If evolution was to become science, a causal explanation had to be offered.
Such an explanation was proposed by Jean Babtiste Lamarck toward the end of the eighteenth century, and Lamarckianism became the best-known pre-Darwinian theory of evolution. According to Lamarck, the acquired characteristics of parents could be handed down to their offspring (Edey and Johanson, 1989, pp. 22-26). Suppose, to take the most familiar example, that the ancestral giraffe had a neck of ordinary length. Because the lower branches of the trees they fed off were easily denuded, these early giraffes stretched out their necks to reach higher branches. In so doing, they caused their offspring to be born with slightly longer necks, until the ultimate result was the giraffe of today.
Lamarckian evolution had delightful implications that went far beyond the necks of giraffes. Virtue, it seemed, was its own reward, at least in the next generatio
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