Puzzle 11

John Baez

Q: When was the toothpick invented?

A: At least 1.7 million years ago. A molar from Tanzania's Olduvai gorge, somewhere between 2.1 million and 1.7 million years old, bears unmistakable evidence of having been repeatedly probed by a sharp piece of wood or bone. The tooth in question belongs to either Homo habilis or early Homo erectus. Similar grooves have been found in the teeth of other homimids, including Neandertals, but they have not been found in the more primitive Australopithecus or in primates such as chimpanzees.

Source: Random Samples, ed. Constance Holden, Science, 288 (28 April 2000), p. 607.

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