Bada J L, Gillespie R, Gowlett J A, Hedges R E
Nature. 1984;312(5993):442-4. doi: 10.1038/312442a0.
A decade ago, aspartic acid racemization ages were determined for some skeletal remains found in California, near La Jolla, Del Mar and Sunnyvale, suggesting that people were present in North America during the Upper Pleistocene. These ages were obtained from the aspartic acid racemization rate, which was calibrated using a radiocarbon date of 17,150 +/- 1,470 yr BP determined for a skeleton found in Laguna Beach, California. These studies generated an intense controversy not only about the antiquity of human beings in the New World but also about the validity of racemization-based ages, and prompted efforts to date the finds by other means. Here we have used accelerator mass spectrometry (AMS) to determine the radiocarbon ages of the amino acid extracts used in the original racemization studies. Our studies indicate that some of the controversial Californian skeletons, which had been assigned to the Upper Pleistocene, are in fact Holocene.
十年前，对在加利福尼亚州拉霍亚、德尔马和桑尼维尔附近发现的一些骨骼遗骸测定了天冬氨酸消旋年龄，这表明在上更新世时期北美就有人类存在。这些年龄是根据天冬氨酸消旋速率得出的，该速率是通过对在加利福尼亚州拉古纳海滩发现的一具骨骼测定的17150±1470年前的放射性碳年代校准得到的。这些研究不仅引发了关于新世界人类古老性的激烈争论，也引发了关于基于消旋作用的年龄有效性的争论，并促使人们努力通过其他方法对这些发现进行年代测定。在这里，我们使用加速器质谱法（AMS）来测定原始消旋作用研究中使用的氨基酸提取物的放射性碳年龄。我们的研究表明，一些曾被认定为上更新世的有争议的加利福尼亚骨骼实际上是全新世的。
