claim: The failure of the 2007 polar bear survival model is a simple fact that explodes the myth that polar bears are on their way to extinction.
evidence: The Quaternary period ( from 2.588 ± 0.005 million years ago to the present ) saw the extinctions of numerous predominantly megafaunal species, which resulted in a collapse in faunal density and diversity and the extinction of key ecological strata across the globe.