What do gorillas and humans have in common?

Gorillas survive today in just a few isolated and endangered populations. Image: Shutterstock

The gorilla genome has given scientists an insight into human evolution.

Researchers announced they have completed the genome sequence for the gorilla. As this was the last genus of the living great apes to have its genome decoded, scientists were able to compare the genome for chimpanzees, gorillas, humans and orangutans for the first time.

The team analysed over 11,000 genes in chimpanzees, humans and gorillas for genetic changes in evolution. The results confirmed that the chimpanzee is our closest relative, but revealed that our genome is more closely resembles the gorilla genome — up to 15 per cent of our genome is closer to the gorilla’s.

“The gorilla genome is important because it sheds light on the time when our ancestors diverged from our closest evolutionary cousins,” said author Aylwyn Scally, from the Wellcome Trust Sanger Institute in the UK. “It also lets us explore the similarities and differences between our genes and those of gorilla, the largest living primate.

The findings not only revealed differences in the species as a result of millions years of evolutionary divergence, but also parallel changes over time. For example, genes related to hearing, sensory perception and brain developed showed accelerated evolution in all three species, particularly in humans and gorillas.

“Scientists had suggested that the rapid evolution of human hearing genes was linked to the evolution of language,” said author Dr Chris Tyler-Smith, from the Wellcome Trust Sanger Institute. “Our results cast doubt on this, as hearing genes have evolved in gorillas at a similar rate to those in humans.”

The genomes also indicated that gorillas diverged from humans and chimpanzees around ten million years ago. “After decades of debate, our genetic interpretations are now consistent with the fossil record and provide a way for palaeontologists and geneticists to work within the same framework,” said author Dr Richard Durbin, from the Wellcome Trust Sanger Institute.

“Our data are the last genetic piece we can gather for this puzzle: there are no other living great ape genera to study.”

DNA sequences from different gorilla species suggested that the split between eastern and western gorillas was much more recent and occurred gradually, although they are now genetically distinct. This split is comparable in some ways to the split between modern humans and Neanderthals.

– Laura Boness

Source: Wellcome Trust Sanger Institute

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