Scientists have sequenced the genome of the gorilla, the last great ape to have its genes decoded, and say it gives new insights into differences between the apes and humans.While confirming that our closest relative is the chimpanzee, the research also shows that around 15 per cent of the human gene map resembles the gorilla more closely than it does the chimpanzee genome.Chris Tyler-Smith, who worked with a team of scientists who presented their findings in a telephone briefing on Wednesday, said that while many human genes are similar to the gorilla versions, it is the ones that differ that are often most intriguing.One difference that stuck out was in the genes involved in sperm production, he said."Gorillas live in groups with one male and lots of females, so there’s not much opportunity for sperm competition,” he explained."It was interesting for us to see that some genes involved in sperm formation...had either become inactive in gorillas or had decreased in copy number.”The study was published in the journal Nature on Wednesday.Gorillas survive in just a few isolated and endangered populations in the equatorial forests of central Africa. There are two distinct species, one known as the eastern lowland and mountain gorillas, and the other known as western lowland and cross river gorillas.