Scientists on Wednesday said they have unravelled the genetic code of the gibbon, shedding light on one of the most enigmatic members of the ape family.
Gibbons, whose rainforest home ranges from northeast India to Southeast Asia and southern China, occupy an unusual place in the primate family tree.
Lithe creatures which use super-long arms to swing acrobatically from branch to branch, they are, officially, Lesser Apes.
They are superficially similar to monkeys yet also share many characteristics with humans, who are part of the Great Ape group with chimps, bonobos, orangutans and gorillas.
Gibbons bond in pairs and are monogamous, lack a tail, walk upright on legs -- and even have a fondness for singing as they call to each other across the jungle.
Reporting in the journal Nature, an international team said they had sequenced the genome of a female northern white-cheeked gibbon, Nomascus leucogenys in Latin.
Genetically, gibbons were the first primate species to diverge from Great Apes, an event that happened around 17 million years ago, the scientists said.
In a series of fast-track events that probably spanned less than two million years, gibbons split into four sub-groups, called genera -- dwarf gibbons, crested gibbons (of which the Nomascus gibbon is a member), hoolock gibbons and the siamang, the only member of the Symphalangus genus.
The analysis suggests that gibbon DNA has a lot in common with that of apes and humans.
"The genetic information itself is similar to ours," said Christian Roos, a primate genetics scientist at the Deutsches Primatenzentrum (DPZ) in Germany.
"However, large segments of DNA and in many genes are arranged differently on the individual chromosomes," a phenomenon caused by a "jumping" gene.
The mechanism, called a LAVA transposon, increases the rate at which DNA mutation occurs, which explains why evolutionary change occurred in such a short of space of time.
The work should provide a useful contribution to understanding human evolution, say the authors.
It could also help to explain some of the mechanisms in diseases that develop when genetic packaging and regulation get disrupted.
"Cancer is clearly the biggest example of the impact of chromosome re-arrangements," said Kim Worley of the Human Genome Sequencing Center at the Baylor College of Medicine in Houston, Texas, who co-led the probe.
"The gibbon sequence gives more insight into this process. There are also a number of other genetic diseases that result from these events."