Living in trees may have given great apes vocal skills for consonants

The author is Richard Kemeny.

Life in the trees may have given rise to our speech. According to the first analysis of the evolution of consonants, their roots may be related to an arboreal lifestyle.

Humans use a combination of vowels and consonants to communicate. Non-human great apes produce sounds that are different from those of humans.

Adriano says the question of where vowels come from is raised. To find out if common vowels can shed light on the evolutionary origin of the great apes, Lameira combed through existing literature.

He found that orangutans, who spend most of their time in the forest canopy, produce more sounds than other animals. These sounds are not universal in other great apes.

Orangutans have a lot of kiss sounds and clicks. These sounds are used to build a nest, communicate with their young, or make alarm calls.

It is thought that living in the trees may explain why orangutans have evolved a wide vocal range. The use of tools is required when great apes are able to extract nuts. orangutans must always use at least one arm to stay stable. orangutans can peel an orange just by using their lips, and they have developed more complex control of their lips, tongue and jaws.

The advanced motor skill gave orangutans an increased ability to produce sounds. It's possible that our ancestors developed sounds while in the trees.

The idea that humans started walking upright as they moved into the savannah is not true. We might have stayed where the trees were and crossed from one patch to the other as quickly as possible.

The link between feeding and vocal communication doesn't apply to monkeys because of their size and tails.

The arboreal origin of consonants is an interesting hypothesis that is worth testing. Many monkeys use grunts which are similar to vowels. As humans aren't tree dwelling, there must be other reasons why consonants persisted. Characterising vocalisations more systematically across species would be a good way to test these hypotheses.

Serge Wich at John Moores University in the UK believes that testing the hypothesis could provide some insights. Even if there is a relationship that does not mean causality, we have to be very careful as there could be other factors involved.

The journal's title is Trends in Cognitive Sciences.

The revolution in archaeology and human evolution is covered in Our Human Story.