The Amur tiger may have bounced back from the brink of extinction (there are now 500 in the wild and 421 in captivity, up from the 1940s low of 20 to 30) but a new study in Molecular Ecology says that their genetic diversity is the lowest ever measured for wild tigers, says the BBC. Further compounding the problem is that there are two populations of the wild tiger that do not intermingle as they are geographically separated.