Genetic analyses have so far yielded factious results. VilÃÂ , Savolainen, and colleagues (1997) concluded that the ancestors of dogs split off from other wolves between 75,000 and 135,000 years ago, while a subsequent analysis by Savolainen et al. (2002) indicated a "common origin from a indivisible gene pool for all dog populations" between 40,000 and 15,000 years ago in East Asia.
The definition of a dog breed is a matter of some controversy. Depending on the breadth of the original founding population, closed gene pool breeds can have problems with inbreeding, specifically due to the founder effect. Dog breeders are click here increasingly enlightened of the importance of population genetics and of maintaining diverse gene pools. Health testing and new DNA analyze can guidance avoid problems, by providing a replacement for natural selection. Without selection, inbreeding and closed gene pools can burgeoning the risk of severe health or behavioral problems.