Researchers have mapped the genetic blueprint of orang-utans – a move that could greatly assist conservation efforts for the rapidly disappearing ape, writes DICK AHLSTROM, Science Editor
EFFORTS TO protect the severely endangered orang-utan have received a major boost with the publication of the ape’s genetic blueprint. It will provide information that could aid conservation efforts for this threatened species. If any animal needed conservation it is the orang-utan. Its numbers have fallen precipitously over the past few decades due to habitat loss and hunting, according to scientists from Washington University who led the genome work.
Formerly widespread over much of southeast Asia, wild orang-utan populations have been reduced to just two locations: the Indonesian islands of Borneo and Sumatra.
Numbers continue to fall, however, and the orang-utan could become extinct in the wild in as little as a decade, according to Dublin Zoo.
The animals used to be counted in the hundreds of thousands but now are down to between 15,000 and 24,000, says Ciaran McMahon, team leader of the west side of Dublin Zoo, which includes the primates, cats and elephants.
“They are majestic animals and are critically endangered. The reason is that about 80 per cent of the orang-utans’ habitat has been destroyed,” he says.
Orang-utans live in the rainforests of Borneo and Sumatra, but between five and six million acres of forest are lost on the islands every year. “This represents about 300 football pitches of land cleared every 48 hours,” says McMahon.
Loggers fell the trees for timber, but once they have cleared the land it is used to grow oil-producing palms, so it can not revert to a habitat suited to orang-utans, McMahon says. “They live in the trees, they feed in the trees, breed and have their young in the trees. They very seldom come down onto the ground.”
Last November, the zoo organised an orang-utan awareness week, in the process attracting controversy by declaring any red-headed child could enter for free. The event raised €10,000 – money that will be used to buy land and extend a reserve for the animals.
The zoo is a full international participant in efforts to protect the animals in the wild and to ensure their survival, says McMahon.
Dublin Zoo has four Bornean orang-utans, Sibu (32), Leoni (29), Reona (11) and Majur (6), and all are registered on an international “stud book”, which tracks their genetic background.
“It is like a big dating agency,” McMahon says, with the idea being to keep the animals genetically diverse.
Having an orang-utan genome and 10 comparative genomes will greatly aid this work. It will help conservationists assess the genetic diversity of orang-utan populations both in the wild and in captivity, the Washington University research team writes.
The work has also thrown up oddities in the orang-utan genome, the details of which are published this morning in the journal Nature.
It took a significant international effort to produce a genome for a female Sumatran orang-utan (Pongo abelli)named Susie and then comparative genomes from 10 more Sumatran and Bornean (Pongo pygmaeus)orang-utans.
The researchers, led by Dr Devin Locke of Washington University’s Genome Centre, were able to define when in the past the two species separated from a common ancestor. They set this at 400,000 years ago, a significant change from earlier estimates that put this at more than one million years ago.
It also showed that the orang-utan genome has remained amazingly stable with a very low level of change. “In terms of evolution, the orang-utan genome is quite special among great apes in that it has been extraordinarily stable over the past 15 million years,” says senior author Dr Richard Wilson of the Genome Centre.
“This compares with chimpanzees and humans, both of which have experienced large-scale structural rearrangements of their genome that may have accelerated their evolution.”
And yet the orang-utan genome is much more varied, Dr Locke says. “The average orang-utan is more diverse – genetically speaking – than the average human,” he says. “We found deep diversity in both Bornean and Sumatran orang-utans, but it is unclear whether this level of diversity can be maintained in light of continued widespread deforestation.”
Orang-utans are our most distant great ape cousins, despite the fact that we share 97 per cent of our DNA with them. This compares to chimps whose DNA is 99 per cent identical to humans.