South Asian river dolphin display the variances needed to support their classification as separate species. Thus, at present, a single species with two subspecies is recognized in the genus "Platanista", "P. g. gangetica" (Ganges river dolphin) and "P. g. minor" (Indus river dolphin). An assessment of divergence rates in mitochondrial DNA of the two subspecies indicates that they diverged from a common ancestor around 550,000 years ago. This ancestor is thought to have been a marine Platanistid inhabiting the epi-continental seas in South Asia during the sea level rises in the middle Miocene. The earliest fossil identified as belonging to the species is only
Endangered Species Act of 1973 landowner will not be required to do more than already agreed upon in the CCA. The Experimental Population Provision encourages introductions of species into formerly occupied or new habitat without the full range of legal restrictions for endangered species. The provision was added to the act in 1982 to encourage landowner support for species survival and recovery. Experimental populations could be used for the assisted migration of endangered species. To delist species, several factors are considered: the threats are eliminated or controlled, population size and growth, and the stability of habitat quality and quantity. Also, over a dozen species have