Similipal tiger reserve has always had an isolated tiger population in the eastern part of India, but with almost zero connectivity with other tiger reserves, or the absence of any other tiger population in its vicinity, the population remained isolated for decades, which caused inbreeding among a very small founding population of tigers. It is believed that the decades of inbreeding has resulted in a single mutation in the Transmembrane Aminopeptidase Q (Taqpep) gene. Many experts have pointed towards inbreeding as the primary reason for the black tigers of Similipal.