The eastern lowland gorillas in the Democratic Republic of the Congo have experienced a dramatic decline in population in recent decades, leading to a sensational lack of genetic diversity and a threatened outbreak. Numerous harmful mutations according to new research results.
Comparing the genomes of living gorillas of the Eastern lowlands, also known as Gray's gorillas, with genomes from museum specimens, researchers from the Swedish Museum of Natural History (SMNH) and the University of Uppsala have shown that genetic diversity decreases in species while the inbreeding increases. This double whammy syndrome is due to declining populations and causes an effect called "temporal genomic erosion" where the lack of genetic diversity introduces deleterious mutations into gray gorillas, including fertility problems and reduced ability to fend off infectious diseases. The new research was published today in Current Biology.
It is needless to say that this makes an already dire situation worse for the Gray Gorilla. But while the genetic diversity of these gorillas is sinking sharply, it has not yet reached the point of no return ̵
1; a condition called "genetic breakdown". Thereafter, there is not enough diversity in the gene pool to be able to reproduce. There is still time to bring these monkeys back from the abyss, all we have to do is act.
Over the past two decades, the population of Gray Gorillas in the Democratic Republic of the Congo has declined by 80 percent. Due to poaching and habitat loss, less than 4,000 people now live and the species is considered critically endangered. To see whether this decline in population was reflected in a loss of genetic diversity, the researchers at SMNH and Uppsala investigated past eastern gorilla genomes in the past century by examining samples collected in museums. It is the first study to use historical genomes of a vulnerable species to study changes in genomic variation over time.
"We believe that this approach can be implemented to a much greater extent in endangered species in general," said Dear Dalén, researcher at SMNH and co-author of the new study, told Earther.
Dalén and his colleagues sequenced 11 genomes from eastern gorillas that were 100 years old. The DNA of the archived samples obtained from teeth and dry tissue samples has been severely degraded. By using the same methods that are normally used to restore older samples such as mammoths and Neanderthals, scientists were able to recover good and reliable genetic data.
"Of course, it would have been great if we could have sequenced more museum pieces, as this would have enabled a higher resolution," Dalén told Earther. "Overall, finding significant changes in Gray's gorillas is robust, in my opinion, because statistical significance accounts for the small sample size."