Wildlife of Russia bears and whales. In the taiga forests, species include squirrels, chipmunks, voles and lemmings. The carnivores are polecats, brown bear, lynx, wolves, foxes, wolverines and the sable. Elk, a large deer about in height up to the shoulder, are common in this habitat. Steppe animals include wild boar as well as 30 other mammal species. A small antelope species known a saiga antelope is also present but is under threat due to hunting. Animals species in the Caucasus region are tur (two species of mountain goat), bezoar (wild goat) endangered mouflon (mountain sheep), chamois (an antelope), Persian leopard, brown bear
Dmitry Belyayev (zoologist) also been of great interest to Darwin. It was recognized that domesticated animals differ in several ways from their wild counterparts, but it was not known what principle of selection had guided the Neolithic farmers who had first domesticated these species thousands of years ago. Belyayev's hypothesis was that "all domesticated species had been selected for a single criterion: tameness." Belyayev further theorized that this attribute "had dragged along with it most of the other features that distinguish domestic animals from their wild forebears, like droopy ears, patches of white in the fur and changes in skull shape." In other