People and apes

PanARMENIAN.Net - In Malay and Indonesian orang means "person" and utan is derived from hutan, which means "forest." Thus, orangutan literally means "person of the forest."

Orangutans are among the most intelligent primates; they use a variety of sophisticated tools and construct elaborate sleeping nests each night from branches and foliage. The apes have been extensively studied for their learning abilities. Nevertheless, the most interesting fact about the orangutans is that they share 97% of their DNA with people.

In 2009, a study contended that orangutans, not chimpanzees, are the closest living relatives to humans. The authors based their conclusion on a close physical resemblance between orangutans and humans, which they said was overshadowed by genetic evidence linking people to chimps. What's more, the study authors argued, the genetic evidence itself was flawed. John Grehan, of the Buffalo Museum of Science in New York State, and Jeffrey Schwartz, of the University of Pittsburgh in Pennsylvania, said that the DNA evidence cited by many scientists only looks at a small percentage of the human and chimp genomes. What's more, the genetic similarities likely include many ancient DNA traits that are shared across a much broader group of animals. By contrast, humans share at least 28 unique physical characteristics with orangutans but only 2 with chimps and 7 with gorillas, the authors said.

Orangutans' arms stretch out longer than their bodies - over two metres from fingertip to fingertip - and are used to employ a "hookgrip". When on the ground, they walk on all fours, using their palms or their fists

In 2011, an international team of researchers cracked the genetic code of the endangered great apes, hoping that their findings will aid efforts to protect the species from extinction.

Today, only about 50,000 Bornean and 7,000 Sumatran orangutans remain in the wild. Their numbers have been dwindling as a result of deforestation. Both species are classified as Critically Endangered according to the International Union for the Conservation of Nature and Natural Resources (IUCN) Red List of Threatened Species.

The scientists first sequenced the genome of a female Sumatran orangutan named Suzie. Using her DNA as a 'reference' they then compared the results with the DNA from another five Sumatran and five Bornean orangutans. They recorded around 13 million DNA variations in the apes and found the two species split around 400,000 years ago - much more recently than previously thought.

“The orangutan genome appears to have evolved more slowly than those of humans and chimpanzees and has been "extraordinarily stable over the past 15 million years. Humans and chimpanzees genomes are more changeable, which may have helped accelerate their evolution," author Richard Wilson, of Washington University's Genome Center, said.

When males are fighting, they charge at each other and break branches. If that doesn't scare one of them away, they grapple and bite each other

In 2017, researchers at Durham University, UK, said that the warning sounds of orangutans may reveal more than just danger. Important building blocks for human speech may have evolved from kiss squeaks - the alarm calls like lip smacks, clicks and raspberries - produced by orangutans. The study suggests that language may have evolved through the combination of these sounds with voiced calls, produced by the controlled expulsion of air, which more closely resemble human vowels.

Dr Adriano Lameira, from Durham University, looked at recordings of 4,486 kiss-squeaks taken from 48 individuals in four wild populations of orangutans. The team studied the warning calls because they are voiceless, relying on the movement of the mouth rather than the controlled expulsion of air. This makes them similar to consonants, one of the basic building blocks of human speech alongside vowels.

Previous studies by Dr Lameira and his team have also revealed 'faux-speech' grunts in orangutans that are similar to human vowel sounds. Kiss-squeaks are only produced by orangutans among primates, although other species have their own alarm calls. His team wanted to establish whether kiss-squeaks could transmit similar information to voiced calls. Their report suggests that the early predecessors to syllables and words were probably made up of a combination of these two elements. Language may have developed through repetition and variation of these combinations, rather than increasing levels of complexity, according to their findings.

For the first 4-6 years of his/her life, an infant orangutan holds tight to mother's body as she moves through the forest in search of fruit

“Because we tend to think of words as a very sophisticated human behavior, when we started to research the "why" for the evolution of the first words, we expected something to do with complexity,” Dr Lameira told Mail Online. “What our results showed was that, contrarily, the forces favoring the evolution of words were probably assuring redundancy, not complexity.”

Dr Lameira's previous work, according to Mail Online, has also brought into question the idea that the great apes could not learn new sounds. He studied an orangutan called Rocky at Indianapolis Zoo, Indiana, between April and May 2012. During the study, a researcher made random sounds, varying the tone or pitch of her voice. Rocky then mimicked the sounds, which the team compared against a database of orangutan calls, collected form over 12,000 hours of observations of more than 120 orangutans from 15 wild and captive populations. The sounds made by Rocky were different to the sounds on the database, showing that he was able to learn new sounds and control the action of his voice in a 'conversational' context.