How many animals do we require to avert extinction?

Frankham et al. 2014. Biological Conservation, 170, 56–63.This analysis indicates that the genetically effective population size of 50 breeding adults is not adequate to reduce the effects of inbreeding depression, and the numbers required are more than 100 individuals to prevent inbreeding depression over five generations in the wild. The minimum numbers for retaining evolutionary potential for fitness should be more than 1000 breeding adults rather than the 500 that has been postulated. The authors state that this genetic information requires that population viability analysis should be suitably revised to be more effective in conservation of endangered species. This paper is of vital importance for the conservation of our large mammals such as the Asian elephant (Elephas maximus) and the Bengal Tiger (Panthera tigris tigris) that are severely affected by habitat loss and poaching in the subcontinent.