The loss of genetic diversity may not play as large a role in the demise of threatened and endangered animals as conservation biologists once believed, according to a three-year study of wild cheetahs published in a recent issue of the journal Science. "The central paradigm in conservation biology over the last decade has been that genetics are critically important in determining the fate of small populations," says zoologist Tim Caro, a UC Davis associate professor who has studied cheetahs for 14 years. "In the face of massive species losses, we should redirect efforts toward addressing ecological rather than genetic problems." The most immediate threats to small wild populations are posed by humans, according to the researchers, who listed problems such as poaching, habitat fragmentation, decimation by introduced species and pollution.