Bonobos are more endangered than we previously understood 

Bonobos, a species of endangered great apes that are among our closest relatives, might be more vulnerable to extinction than previously thought. 

This is the conclusion of a genetic study co-led by scientists from the University College London (UCL), the University of Vienna, and the Max Planck Institute for Evolutionary Anthropology.

Three separate bonobo populations 

The researchers discovered that three groups of bonobos have been living separately in different regions of Central Africa for tens of thousands of years. 

Using genetic tests, the researchers confirmed previous evidence suggesting that these groups originate from central, western, and far-western regions of the bonobo range. 

By quantifying the differences between these groups, the research team found that they can be as distinct from one another as the most closely related chimpanzee subspecies.

Bonobos: Our endangered relatives

Bonobos, commonly seen as the peace-loving primate, are, together with chimpanzees, the closest living relatives to humans, with our genomes differing from theirs by only one percent. 

Despite this close relationship, bonobos are endangered, with about 20,000 individuals alive in the wild. 

They are also the most understudied great apes, as they live exclusively in the Congo Basin of the Democratic Republic of the Congo, where social unrest has constrained research activities.

Unique social behaviors of bonobos 

“Bonobos are a fascinating species, very closely related to humans, with unique patterns of social behavior,” said co-first author Sojung Han, a scientist at the University of Vienna. 

“They live in tight social groups which, despite some conflicts, are markedly peaceful and egalitarian. Interestingly, males stay in their birth social group while females migrate across groups, but females still form close alliances and can have higher dominance than males.”

The research team analyzed the genomic data of 30 bonobos born in the wild but now living in captivity. They sequenced the exomes (the protein-coding part of the genome) of 20 individuals residing in an African sanctuary and analyzed the full genomes of 10 other bonobos. 

While the exact regions of origin within the Congo Basin for each bonobo were not always certain, the researchers cross-referenced their dataset with previously published mitochondrial DNA data collected from 136 wild bonobos to create a comprehensive picture of genetic diversity across the species’ range.

Endangered bonobos populations 

The researchers estimated that the central group diverged from the other two groups approximately 145,000 years ago, with the two western groups diverging around 60,000 years ago, showing little mixing between the groups since then. 

“Bonobos may be even more vulnerable than previously thought, as their population actually consists of at least three smaller populations, some of which may historically have been amongst the smallest across similar primates,” said study senior author Aida Andrés, an expert in genetics at UCL. 

“In order to survive, every species needs sufficient genetic diversity to adapt to a changing environment, and for bonobos, losing one of these three groups would be a devastating loss to the total genetic diversity of the species.”

According to Andrés, it is vital that all three groups of bonobos are conserved in order to protect this fascinating and charismatic species.

Implications for conservation efforts

The researchers advocate that the genetic differences between bonobo groups should be further studied and considered in conservation strategies. 

This includes habitat preservation, translocations, or potential reintroductions, especially if individuals are adapted to specific environments.

“Unlike modern humans, who are spread all over the world, bonobos are limited to the Congo basin, but our work shows that there are indeed genetic differences between groups,” said Han. 

:This is exciting, and it will be very interesting to study, in the future, if there are any differential adaptations among these groups.”

Genomes of endangered bonobos 

According to study co-author Cesare de Filippo from the Max Planck Institute, this work demonstrates how studying the genomes of endangered species can help better understand their populations and eventually aid conservation efforts. 

“Even the genomes of captive individuals can help us, sometimes, understand their wild populations. Our findings show the vulnerability of bonobos as an endangered species, and stress the need to protect their environment to ensure their conservation,” said de Filippo.

This groundbreaking genetic study highlights the critical need to preserve all three distinct bonobo populations to maintain the species’ genetic diversity and adaptability. 

As one of humanity’s closest relatives, understanding and protecting bonobos not only aids in their conservation but also enriches our knowledge of primate evolution and social behavior.

The study is published in the journal Current Biology.

—–

Like what you read? Subscribe to our newsletter for engaging articles, exclusive content, and the latest updates.

Check us out on EarthSnap, a free app brought to you by Eric Ralls and Earth.com.

—–