Detailed study of critically endangered mountain gorillas has revealed that the apes are burdened with severe inbreeding and are at risk of extinction. However, in spite of this, scientists are still optimistic about their survival. The research is the most extensive genetic analysis of mountain gorillas ever conducted and included twenty three scientists from six countries who unveiled the first complete genetic map of the species. Mountain gorilla is a close genetic cousin of humans and can be found in two isolated areas in central Africa. The study has been detailed in the journal Science.
Geneticist Chris Tyler-Smith of Britain’s Wellcome Trust Sanger Institute said “We found extremely high levels of inbreeding.” The study has also revealed substantial loss of genetic diversity due to inbreeding. Mating with close relatives due to small population size is leading to the inheritance of identical segments from both parents in about a third of their genome. Inbreeding increases the threats from diseases as well as environmental change.
University of Cambridge geneticist Aylwyn Scally stated “Mountain gorillas are critically endangered and at risk of extinction, and our study reveals that as well as suffering a dramatic collapse in numbers during the last century, they had already experienced a long decline going back many thousands of years.” The study surprised the researchers as they found that many of the harmful mutations which can stop genes from working and cause serious health conditions were less common as compared to other gorilla subspecies. Scally added “We have shown that although low in genetic diversity they have not yet crossed any genetic threshold of no return. They can continue to survive and will return to larger numbers if we help them.”
There are around 880 mountain gorillas dwelling in mist-covered forests of the Virunga volcanic mountain range on the borders of Rwanda, Uganda and the Democratic Republic of Congo and Uganda’s Bwindi Impenetrable National Park. For the study, blood samples from seven Virunga gorillas were taken. Copenhagen Zoo geneticist Christina Hvilsom mentioned “While comparable levels of inbreeding contributed to the extinction of our relatives the Neanderthals, mountain gorillas may be more resilient.” The study also suggests that these gorillas are mainly threatened by human activities and the threats include habitat loss, disease transmission from humans and hunting.