So the test can identify pre-1955 ivory by its low, pre-nuclear-test levels of carbon-14.
Cerling says the method can determine the year of death for any animal killed after 1955, identifying the time of the most recent tissue formation – at the base of a tusk or tooth, for example.
It was published online the week of July 1 in the journal Proceedings of the National Academy of Sciences. "It has immediate applications to fighting the illegal sale and trade of ivory that has led to the highest rate of poaching seen in decades," says Uno, now a postdoctoral researcher at Columbia University's Lamont-Doherty Earth Observatory.
"The dating method is affordable and accessible to government and law enforcement agencies," costing about 0 per sample, says the study's first author, geochemist Kevin Uno, who did the research for his University of Utah Ph. Not only can the method help wildlife forensics to combat poaching, but "we've shown that you can use the signature in animal tissues left over from nuclear weapons testing in the atmosphere to study modern ecology and help us learn about fossil animals and how they lived," says Cerling, a distinguished professor of geology and geophysics, and biology at the University of Utah. and Soviet atmospheric nuclear weapons tests in Nevada and Siberia from 1952 through 1962.
The United States is the next biggest illegal market.
Rising ivory prices have drawn organized crime and spurred militias in Darfur, Uganda, Sudan and Somalia to kill elephants and sell tusks so they can buy guns.
So as part of the new study, the scientists also analyzed another 41 samples to determine the growth rates for tusks and teeth from elephants and hippos, and elephant tail hair, Cerling says.
Extrapolating the growth rates of tusks, teeth and hair to fossil or modern elephants and other animals "will help us improve the chronology of the diet history of an individual fossil or modern animal," Cerling says.
The conventional way of measuring carbon-14 is to wait for and count when the isotope decays radioactively.Understanding Ancient and Modern Ecosystems While the method's use against poaching is important, "the scientific part is the importance of understanding time in the formation of animal tissues and how diet and physiology is recorded in those tissues over time" as they grow, Cerling says.Cerling says that will improve understanding of what prehistoric and modern animals ate over time, especially when combined with existing isotope analysis of ratios of carbon-13 to carbon-12 in teeth – data that reveal whether animals ate diets based on tree and shrub leaves and fruits, or upon grasses and grazing animals.Cerling and Uno conducted it with geologist Jay Quade, a former Utah doctoral student now at the University of Arizona; Daniel C.Fisher, University of Michigan, Ann Arbor; George Wittemyer, Colorado State University; Iain Douglas-Hamilton, founder of Save the Elephants; and Samuel Andanje, Patrick Omondi and Moses Litoroh, all of the Kenya Wildlife Service.