The most widespread carnivores are leopards; they are living in a wide range of habitats, from deserts to rainforests, and from the lowland plains to the mountainous highlands. During the past century, they have experienced extreme habitat losses due to human activity both directly from hunting and indirectly from habitat reduction and prey competition. This has led to the land they occupy being reduced by over 50% in Africa, and over 80% in Asia, involving the local extinction of many populations.
To conduct the genetic analysis they are collecting fresh tissue samples. For leopards collecting the genetic samples would be extremely difficult. The animals are hard to track down, particularly in areas where they are rare, and invasive sampling can be bad for the animal. Animals bred in zoos may not be a good option as they may be mixtures of multiple wild populations.
Brown bears and polar bears diverged around 1 million years ago. The cause of this genetic differentiation of Asian leopards is their out-of-Africa dispersal. Although the evidence suggests that leopards in south-western Asia carry DNA that’s relatively similar to African leopards, which could be due to occasional interbreeding, the overall distinctiveness of leopards on the two continents has been maintained.