Racemization of amino acids in fossil bones and teeth from the Olduvai Gorge region,Tanzania, East Africa

Investigation of amino acid racemization in fossil bones and teeth from the Olduvai Gorge region, Tanzania, indicates that aspartic acid racemization can be used to date samples which are less than ～80,000–100,000 years old in this area. In older samples, significant secondary aspartic acid is apparently present and thus these samples have lower than expectedD/L aspartic acid ratios. Isoleucine in older samples, however, is apparently syngenetic with the samples, so the epimerization of isoleucine to alloisoleucine can be used with certain limitations to date fossil bones and teeth from the older stratigraphic sections in the Olduvai region.