Mountain gorilla genome reveals inbreeding

Mountain gorillas’ DNA reveals a long decline in numbers that has led to massive inbreeding.

An international group of researchers examined the genomes of seven mountain gorillas and six eastern lowland gorillas. The two are genetically distinct subspecies, the team reports in the April 10 Science. Those subspecies last bred with western lowland gorillas about 20,000 years ago. Since then, both populations have dwindled dramatically.

Mountain gorillas are now so inbred that their relatedness is similar to that reported in 2013 in a Neandertal woman whose parents were half-siblings. The good news is that the inbreeding seems to have kicked many harmful mutations out of the mountain gorillas’ gene pool.

Still, the great apes’ lack of genetic diversity may make them more vulnerable to disease and environmental changes. “The demographic histories of mountain and eastern lowland gorillas bear unhappy resemblance to similar histories inferred from Neandertals before their disappearance,” the researchers write.