Genomic analysis details eastern gorilla's declining genetic health

Dec. 27 (UPI) -- New analysis of the critically endangered Grauer's gorilla's genome suggests the species' health is suffering from a loss of genetic diversity.

Scientists sequenced the genomes of several eastern gorilla specimens collected a century ago and compared the results to the genomes of modern Grauer's gorillas. The results, published Thursday in the journal Current Biology, showed Grauer's gorillas have accumulated harmful mutations as they have lost genetic diversity.

"We found that the genetic diversity in Grauer's gorilla has declined significantly in just a few generations," Tom van der Valk, a doctoral student at Uppsala University in Sweden, said in a news release.

Over the last several decades, poaching and habitat losses in the Democratic Republic of the Congo have led to an 80 percent decline in the Grauer's gorilla population.

Declining genetic diversity can not only lead to harmful mutations, but can also leave species less able to adapt to new diseases and shifting environments.

Grauer's gorilla is one of many species experiencing the consequences of interbreeding. As populations shrink, relatives are more likely to mate.

"This recent increase in harmful mutations really emphasizes the need to reverse the ongoing population decline in Grauer's gorillas," said Love Dalén at the Swedish Museum of Natural History.

Previous studies have revealed a decline in genetic diversity among Chinook salmon in the Pacific Northwest, as well as Colorado's bighorn sheep and California's mountain lions.

Several of the gene mutations found among modern eastern gorillas are associated with physiological problems, including stunted disease resistance and declining male fertility. Researchers also identified a population mutation among the genetic sequence involved in toe and finger development, which could explain why some eastern gorillas have fused digits.