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(To hear a radio interview with George, visit The only other animals with similarly long life spans are the giant tortoise and the giant clam, which some have claimed can live about 150 and 220 years, respectively.They needed scientific data, however, to prove the whales longevity.Shell middens are one of the most important and widespread indicators for human exploitation of marine resources and occupation of coastal environments.Establishing an accurate and reliable chronology for these deposits has fundamental implications for understanding the patterns of human evolution and dispersal.DNA stability is a major complication in the analysis of ancient genetic material.Additionally, characterization of nucleic acids can often be difficult and time-consuming. Unfortunately, none of the proteins amino acids racemize as fast and thus, there is, in general, no detectable amounts of racemization other than for aspartic acid, he explains.Following this analysis, Bada turned over the results of the chromatography measurements to Judith Zeh, a statistician at the University of Washington in Seattle, to estimate the ages of the bowhead whales.
Bada and his colleagues studied the eye lenses of 48 bowhead whale carcasses harvested between 19.The proteins in each lens nucleus were acid hydrolyzed into free amino acids, which were then derivatized.The levels of D- and L-aspartic acid were analyzed by ion exchange chromatography or reversed-phase HPLC.Chemical Whale Tales Since 1981, whale hunters in Alaska have found at least six harpoon heads in bowhead whales that they have killed in the Beaufort Sea, southwest of the Arctic Ocean. Anthropologists at the Smithsonian Institution (Washington, DC) estimate that they are between 130 and 200 years old and were probably used by Inupiat hunters in the late 1700s.This circumstantial evidence led Craig George and fellow researchers at the Department of Wildlife Management (North Slope Borough, Barrow, AK) to believe that bowhead whales, named for their exaggerated jaw curve, could have a life span of more than 200 years.The eye lens of a bowhead whale is made up of dozens of layers of protein, much like an onion.The first layer is completely formed while the animal is still in the womb, and then becomes biologically inactive (Figure 2). Similar to the rings on a tree trunk, the lens of a whales eye is composed of concentric spheres of protein, with the oldest rings nearest the center.Results obtained in this study indicate that the application of this new method of AAR dating of shells has the potential to aid the geochronological investigation of shell mounds in different areas of the world.Racemization is the process in which one enantiomer of a compound, such as an L-amino acid, converts to the other enantiomer.Researchers turned to Jeffrey Bada and his colleagues at the Scripps Institution of Oceanography in La Jolla, CA, who are considered experts in the field of racemization analysis.By conducting aspartic acid racemization measurements using an HPLC/fluorescence detection method, Bada analyzed the bowheads eye lenses to estimate the whales age at the time of death (2).