(1993). For example Australia's wildlife is constantly under attack from introduced species that came to Australia with the settlers like pigs, cane toads, foxes, and goats. Domesticated animals also face human caused problems.
The main problem with domestication is that only a select few genetic combinations and species are selected to breed. This causes genetic erosion within species of stock animals. This makes stock animals vulnerable to disease and environmental conditions that are not common to the normal stock animal such as drought. For example, back in the 1970s most of the cattle in Africa were of an imported breed. Local breeds of African cattle had almost completely been
replaced by these imports, however, a few small herds remained. When a 7-year drought hit the continent most of the imported cattle were wiped out, as they had not evolved to endure drought conditions. (Kaufman and Franz, 1993, 361). In order to rebuild their herds, the African native breeds of cattle where reintroduced because they had evolved to withstand the effects of cyclic periods of drought.