First gorilla genome map offers clues to human evolution

(CNN) -- The first complete gorilla genome has been mapped by scientists giving fresh insights into our own origins.

Gorilla are the last of the genus of living great apes (humans, chimpanzees, gorillas and orang-utans) to have their DNA decoded, offering new perspectives on their evolution and biology.

"The gorilla genome is important because it sheds light on the time when our ancestors diverged from our closest evolutionary cousins around six to 10 million years ago," says Aylwyn Scally, postdoctoral fellow at the Wellcome Trust Sanger Institute, Cambridge and lead author of the report.

"It also lets us explore the similarities and differences between our genes and those of gorilla, the largest living primate," he added.

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A team of researchers examined more than 11,000 genes in humans, chimpanzees and gorillas, looking for evolutionary clues.

Initial findings have revealed that 15% of the gorilla genome is closer to human DNA than to our nearest evolutionary relative, the chimpanzee.

Researchers found that genes relating to sensory perception, hearing and brain development showed "accelerated evolution" in all three, but particularly in humans and gorillas.

Having the entire length of the gorilla genome now means scientists can start to compare all the four great apes at every position on the genome, Scally says.

It forms the baseline, he says, from which to move forwards and really explore why and when our genes and those of the great apes diverged.

"Did it happen quite quickly or was it something that gradually happened? At the moment we don't know," he said.

"It could have been some climatic change that separated humans in the east of Africa from chimpanzees in the forest -- that's an idea some have floated. If we can see some imprint of it in the genome that would be very, very useful information."

Scientists used the DNA of a female western lowland gorilla (called Kamilah) who resides at San Diego Zoo.

In the wild, it is the most widespread species of gorilla, according to the World Wildlife Fund (WWF), with a estimated population of 100-200,000 individuals.

The majority are found in Cameroon, Central African Republic, west Congo, Equatorial Guinea, Gabon and Angola.

Its cousin, the eastern lowland gorilla, is less prevalent (fewer than 20,000 individuals) and can only be found in the rainforests of the eastern Democratic Republic of Congo, says WWF.

The research is published in the science journal Nature.