Brace C Loring, Rosenberg Karen R, Hunt Kevin D
Museum of Anthropology, University of Michigan, Ann Arbor, MI, 48109.
Evolution. 1987 Jul;41(4):705-720. doi: 10.1111/j.1558-5646.1987.tb05847.x.
Starting with the onset of the last glaciation approximately 100,000 years ago and continuing to the end of the Late Pleistocene approximately 10,000 years ago, human tooth size began to reduce at a rate of 1% every 2,000 years. Both the mesial-distal and the buccal-lingual dimensions of mandibular and maxillary teeth were undergoing the same rate of reduction. From the beginning of the Post-Pleistocene until the present, the overall rate of dental reduction doubled, becoming approximately 1% per thousand years. Buccal-lingual dimensions are now reducing twice as fast as mesial-distal dimensions, and maxillary teeth are reducing at an even more rapid rate than mandibular teeth. Late Pleistocene rates are comparable in Europe and the Middle East. The Post-Pleistocene rates are also the same for Europe, the Middle East, China, Japan, and Southeast Asia. It is suggested that the cookery at the beginning of the Late Pleistocene allowed the earlier changes to occur. The use of pottery within the last 10,000 years further reduced the amount of selection that had previously maintained usable tooth substance. Reduction then occurred as a consequence of the Probable Mutation Effect (Brace, 1963; McKee, 1984).
从大约10万年前最后一次冰川期开始，一直持续到大约1万年前晚更新世结束，人类牙齿大小开始以每2000年1%的速度减小。下颌和上颌牙齿的近远中径以及颊舌径都以相同的速度减小。从更新世之后开始到现在，牙齿减小的总体速度翻倍，变为大约每1000年1%。现在颊舌径减小的速度是近远中径的两倍，而上颌牙齿减小的速度比下颌牙齿更快。欧洲和中东地区晚更新世的速度相当。欧洲、中东、中国、日本和东南亚地区更新世之后的速度也相同。有人认为，晚更新世初期的烹饪方式使得更早的变化得以发生。在过去1万年里陶器的使用进一步减少了之前维持可用牙齿物质的选择量。随后的减小是可能的突变效应（布雷斯，1963年；麦基，1984年）的结果。
