Scientists identify new species of great ape, Pongo tapanuliensis or Tapanuli orangutan, but fear its survival is already in doubt as habitat under threat
Nicola Davis The Guardian 2 Nov 17;
A new species of great ape has been discovered, according to scientists studying a small population of orangutans in northern Sumatra.
Among the great apes – a group that also includes humans, gorillas, chimpanzees and bonobos – orangutans are our most distant relative. Since 2001, two distinct species have been recognised: the Bornean (Pongo pygmaeus) and Sumatran (Pongo abelii) orangutans. Now, it seems, there is a third.
“It is incredibly exciting to describe a new species of ape,” said Serge Wich, professor in primate biology at Liverpool John Moores University and a co-author of the research. Wich also noted that it was a shock to find such a distinct population given Sumatran orangutans are found just 100km away.
But how long the new species will survive is a moot point: fewer than 800 individuals are thought to exist across a 1,000km2 area, making it the great ape species with the lowest head-count, with threats including illegal trade and habitat loss.
“It is worrying that this species is under so much threat – we have hunting in the area, there is a gold mine [and] there is a hydroelectric plant planned in an area where we find a very high density of the new species,” said Wich.
The new species has been dubbed the Tapanuli orangutan, or Pongo tapanuliensis, after the area spanned by the Batang Toru ecosystem south of Lake Toba in northern Sumatra, where the creatures live.
While it had been reported in the late 1930s that there were orangutans in the area, it wasn’t until 1997 that scientists rediscovered the population and later began studying the animals.
“I was surprised about the extent to which the Tapanuli orangutans differed genetically, morphologically as well as behaviourally from the Sumatran and Bornean orangutans,” said Dr Marina Davila-Ross, another co-author of the study, from the University of Portsmouth.
Writing in the journal Current Biology, an international team of researchers describe multiple characteristics they say indicate the Tapanuli orangutans are a distinct species.
Among the evidence, the team report how they seized the opportunity to examine the remains of an adult male Tapanuli orangutan after it was killed by villagers in November 2013.
The team compared the skull and jaws to those of 33 other adult male orangutans, held in the collections of 10 institutions around the world, revealing differences in numerous metrics – including that the skull of the Tapanuli male is smaller than that of individuals of the other two species.
The authors also looked at the characteristics of living individuals, noting that the long booming calls of the Tapanuli males differ from those of the two other known species and that the creatures have more cinnamon-coloured pelts than Bornean orangutans, with a frizzier texture – particularly when compared to the loose locks of Sumatran orangutans. The team also made note of the facial hair of the Tapanuli orangutans, pointing out that dominant males have prominent moustaches, and the females sport beards.
The researchers also carried out an analysis of the entire genomes of 37 orangutans from across Borneo and Sumatra, allowing them to unpick the animals’ evolutionary “family tree”.
The results suggest that orangutans north of Lake Toba branched off about 3.4m years ago from the more southerly population of ancestral orangutans that first arrived from mainland Asia, giving rise to the Sumatran species. A further split from the population south of Lake Toba occurred about 674,000 years ago, giving rise to the Bornean orangutans as well as the newly discovered species that, like its ancestors, live south of Lake Toba.
“The new species represents the most ancestral line of living orangutans,” said Wich.
The revelations, the team add, have also solved a mystery.
Previous research had found that a type of DNA which is passed down only by mothers, known as mitochondrial DNA, is more similar between Bornean and Tapanuli orangutans, but nuclear DNA – which includes genes from both parents – is more similar between Sumatran and Tapanuli orangutans.
The new study reveals that even after the split between orangutans north and south of Lake Toba, the animals continued to interbreed – likely a result of roving males – resulting in mixing of the nuclear DNA. This was curtailed about 100,000 years ago – a date close to the supervolcanic eruption at Lake Toba – and stopped altogether between 20,000 and 10,000 years ago. Crucially, since the females stayed put, so too did the mitochondrial DNA.
William Amos, professor of evolutionary genetics at the University of Cambridge who was not involved in the study, said it was difficult to be exact when it came to the timings of splits in the evolutionary family tree, but that the evidence for a new species stacked up. “I’m entirely happy that this is at a level where we would recognise [the Tapanuli orangutans] as a different species or at least a subspecies,” he said. “This is clearly a really different population.”
Dr Andrew Marshallof University of York, said that the study highlighted the importance of conservation, and added that there might even be further species of great ape to be discovered.
But Professor Volker Sommer from University College London was less bowled over, pointing out that there is no clear criteria for what constitutes a new species. “Any bunch of expertised biologists can invent a new species, if they get their arguments together,” he said.
New great ape species identified in Indonesia
Victoria Gill BBC News 2 Nov 17;
Scientists who have been puzzling for years over the genetic "peculiarity" of a tiny population of orangutans in Sumatra have finally concluded that they are a new species to science.
The apes in question were only reported to exist after an expedition into the remote mountain forests there in 1997.
Since then, a research project has unpicked their biological secret.
The species has been named the Tapanuli orangutan - a third species in addition to the Bornean and Sumatran.
It is the first new great ape to be described for almost a century.
Publishing their work in the journal Current Biology, the team - including researchers from the University of Zurich, Liverpool John Moores University and the Sumatran Orangutan Conservation Programme - pointed out that there are only 800 individuals remaining, making this one of the world's most threatened ape species.
Early on in their study, researchers took DNA from the orangutans, which showed them to be "peculiar" compared to other orangutans in Sumatra.
So the scientists embarked on a painstaking investigation - reconstructing the animals' evolutionary history through their genetic code.
One of the lead researchers, Prof Michael Krützen from the University of Zurich, Switzerland, explained to BBC News: "The genomic analysis really allows us to look in detail at the history.
"We can probe deep back in time and ask, 'when did these populations split off?'."
The analysis of a total 37 complete orangutan genomes - the code for the biological make-up of each animal - has now shown that these apes separated from their Bornean relatives less than 700,000 years ago - a snip in evolutionary time.
Head to head
For his part in the study, Prof Serge Wich, from Liverpool John Moores University, focused on the orangutans' signature calls - loud sounds the male apes make to announce their presence.
"Those calls can carry a kilometre through the forest," Prof Wich explained.
"If you look at these calls, you can tease them apart, and we found some subtle differences between these and other populations."
The final piece of the puzzle, though, was very subtle but consistent differences in the shape of the Sumatran, Bornean and Tapanuli orangutan skulls.
Prof Wich told BBC News that the decades of collaborative genetic, anatomical and acoustic studies had achieved an "amazing breakthrough".
"There are only seven great ape species - not including us," he said. "So adding one to that very small list is spectacular.
"It's something I think many biologists dream of."
New and disappearing
But this newly described great ape will be added to the list of Critically Endangered species, just as it is added to the zoological textbooks.
"It's very worrying," said Prof Wich, "to discover something new and then immediately also realise that we have to focus all of our efforts before we lose it."
Newly discovered orangutan species is most endangered great ape: study
AFP 2 Nov 17;
A new species of orangutan has been discovered in the remote jungles of Indonesia, immediately becoming the world's most endangered great ape, researchers said Thursday.
"It's the first declaration of a new great ape species in about 100 years," Ian Singleton, co-author of the study and director of the Sumatran Orangutan Conservation Programme, told AFP.
The species, called 'Tapanuli orangutan', lives in the Batang Toru forest on Sumatra island, and numbers only about 800 in total, making it the most endangered great ape in the world, Singleton added.
Until recently, scientists thought there were only two genetically distinct types of orangutan, Bornean and Sumatran.
But in 1997 researchers at the Australian National University discovered an isolated population of the great apes in Batang Toru, south of the known habitat for Sumatran orangutans, and scientists began to study the group to see if it was a unique species.
Researchers studied the DNA, skulls and teeth of 33 orangutans killed in human-animal conflict before concluding that they had indeed discovered a new species, giving it the scientific name Pongo tapanuliensis.
Outwardly the Tapanuli orangutan bears a closer resemblance to its Bornean counterpart, with cinnamon-coloured fur that is frizzier than its Sumatran relative. It also has a "prominent moustache", according to the findings published in the journal Current Biology.
Its skull and bone structure are slightly different from its relatives and so is its behaviour, with the long calls of male orangutans lasting on average 21 seconds longer with a greater number of pulses.
Scientists believe the three types of orangutans share a common ancestor but began to diverge into different species about 3.4 million years ago.
"The Batang Toru orangutans appear to be direct descendants of the initial orangutans that had migrated from mainland Asia, and thus constitute the oldest evolutionary line within the genus Pongo," said co-author Alexander Nater of the University of Zurich.
The Tapanuli orangutan species became isolated from its Sumatran relatives about 10-20,000 years ago, Nater added, eventually settling in the Batang Toru forest.
But its tiny population is under severe threat from mining, agricultural encroachment, illegal logging and a proposed hydroelectric dam, which would flood up to eight percent of its habitat.
The authors of the study said conservation measures need to be urgently implemented.
"Orangutans reproduce extremely slowly, and if more than one percent of the population is lost annually this will spiral them to extinction," co-author Serge Wich, professor at Liverpool John Moores University, said.
Both Sumatran and Bornean orangutans are listed as critically endangered by the International Union for Conservation of Nature (IUCN).
The Sumatran orangutan population is estimated to be just under 15,000, while about 54,000 orangutans are thought to live in Borneo, according to the IUCN.
Rampant logging and the rapid expansion of palm oil plantations have been blamed for destroying their jungle habitat. The primates have also been attacked by villagers who view them as pests and targeted by poachers to be sold as pets.
Sabah-based researcher among scientists who identified new orangutan species
ruben sario The Star 2 Nov 17;
KOTA KINABALU: A Sabah-based wildlife researcher was among a team of international scientists who have helped identify a new orangutan species.
Dr Benoit Goossens, director of NGO research outfit Danau Girang Field Centre, was among wildlife experts involved in the discovery of the Pongo tapanuliensis or Tapanuli orangutan found at three Tapanuli districts in northern Sumatra.
The new species was found after detailed analysis of the orangutan inhabitants of the 150,000ha Batang Toru Ecosystem conservation area on the Indonesian island.
Among those in the international team were researchers from the School of Biosciences at Cardiff University where Dr Goossens is a Reader.
However, it was not until 2013 that the researchers received the skeleton of an adult male orangutan that was killed during conflict, and they realised there were significant physical and genetic differences in these apes.
“By comparing the skull to other orangutan, it was clear that this skull showed dramatic differences,” he said.
This suggested that the Batang Toru population was potentially unique, and the international team led by Professor Michael Krützen at the University of Zürich worked together to gather further evidence.
Part of their work involved completing the largest genomic study of wild orangutan in history.
Prof Krützen said they then realised that the Batang Toru orangutan was morphologically different from other orangutan.
“The pieces of the puzzle fell into place. The oldest evolutionary line in the genus Pongo is actually found in Batang Toru orangutan, which appears to be a direct descendant of the first Sumatran population in the Sunda archipelago,” he said.
Computer modelling reconstructed the population history of the three orangutan species, revealing that the Batang Toru apes have been isolated for 10,000 to 20,000 years.
Cardiff University lecturer Pablo Orozco-ter Wengel said the divergence between the Tapanuli orangutan and the other two orangutan species came as a surprise.
“It pushed the divergence between these species to as far as three million years ago, with the South of Toba orangutan being more similar to the Bornean orangutan, than to the North of Toba orangutan,” he said.
With no more than 800 individuals, the new species of orangutan is now considered the most endangered species of great ape on the planet.
“It’s exciting to describe a new great ape species in the 21st century – however, with such low numbers of the Batang Toru orangutan, it is vital that we now work to protect them,” Dr Goossens said.
“Mining, hunting, deforestation and human encroachment all risk the lives of these great apes. It is crucial that we work to conserve the forest, because if we do not take the steps needed to protect the Tapanuli orangutan, we could see their discovery and extinction within our lifetime,” he added.
