The subject of the whole-genome sequencing was a 35-year-old female western lowland gorilla named Kamilah, who lives at the San Diego Zoo. Her DNA was compared with partial sequences from eastern lowland gorillas in order to explore genetic differences between the two species.
Gorillas are the last of the great apes to be decoded, following chimpanzees in 2005 and orangutans in 2011. This achievement allows scientists to compare the human genome with all three of our closest relatives in the animal kingdom.
The data suggest that gorillas split from their common ancestor with humans and chimps about 10 million years ago, and that chimps and humans split from each other about 4 million years after that, said the report.
Understanding the genetic relationships between us and our evolutionary kin gives scientists a reference point to learn more about humans' DNA, and the gorilla sequencing has yielded surprises already.
For instance, it now appears that a gene called LOXHD1 has evolved just as quickly in humans as it has in gorillas. Scientists had previously hypothesized that this gene was responsible for humans' language abilities, but since gorillas share the gene and not the aptitude, old assumptions are being revisited.
In addition, it turns out that 30 percent of gorillas' genomes are more closely related to humans and to chimps than was previously thought -- even closer than humans and chimps are to each other in some ways. This may lead to new theories about how these species have evolved over time.
There was even an important finding regarding dementia and heart failure: The same gene variants that cause these ailments in humans do not harm gorillas. If we could understand more about why those variants are so harmful in humans but not in gorillas, that would have important [medical implications], said Chris Tyler-Smith, who worked on the study.
In general, the research has concluded that gorillas are even more similar to humans than we had previously assumed.