Man’s Closest Relatives—The Chimpanzee and Its Often-Misunderstood Cousin

Photo byWikimedia commons

At a glance, the picture above might have some thinking that they are looking at the same species. However, it’s two different species, a bonobo and a chimpanzee. But can you tell which one is the bonobo, and which one isn’t?

The one on the left is the more commonly known chimpanzee—one of man’s closest relatives. The ape on the right is a bonobo, another species just as closely related to humans.

While we’ve come to recognize chimpanzees as our closest non-human relatives, the bonobo is less well-known. Yet, bonobos share a remarkable amount of our genes.

Similarities between chimpanzees and bonobos

Chimpanzees and bonobos share roughly 98.7% of their DNA with humans. They are both part of the Pan genus, which split from the human evolutionary line around 5-7 million years ago.

Among primates, they are the closest living relatives to humans. However, despite their genetic similarity, they have evolved into two distinct species.

Both chimpanzees and bonobos have similar body structures, featuring long arms, relatively short legs, and opposable thumbs. Like humans, they are capable of problem-solving and exhibit a wide range of emotions, such as empathy, grief, and joy. (“Let’s learn about chimpanzees and bonobos | snexplores.org”)

Lifespan and habitat

Both species live around 40 to 50 years in the wild, though chimpanzees tend to have slightly longer lifespans than bonobos. In captivity, their lifespans can stretch into their 60s. Chimpanzees inhabit the savannas, forests, and grasslands of central and western Africa. Large populations are found in countries like Tanzania, Uganda, and the Democratic Republic of the Congo.

On the other hand, bonobos are more limited in their range, living only in the dense forests south of the Congo River in the Democratic Republic of the Congo. The river acts as a natural barrier that isolated the bonobo from the chimpanzee over millennia.

How closely related are they?

While both species are closely related to humans, they are also closely related to each other. Despite their similar appearance, chimpanzees and bonobos diverged from a common ancestor around 1-2 million years ago. While they are different species, they are close enough genetically to interbreed, just like how ancient humans and Neanderthals once did, while also being different species.

When did scientists realize they were different species?

For a long time, bonobos were thought to be a smaller type of chimpanzee. It wasn’t until 1929 that scientists recognized them as a distinct species. One of the differences between the two species is their overall size and build. Bonobos tend to have a more slender, graceful frame, with longer legs in proportion to their arms. They also have darker faces with pink lips, while chimpanzees often have lighter faces that darken as they age.

The peaceful bonobo vs. The aggressive chimpanzee

Behaviorally, the two species are very different. Chimpanzees are known for their aggressive behavior and violent clashes. They also live in a hierarchical society where the males dominate. Male chimpanzees form coalitions to assert dominance, and they use their strength and intelligence to maintain control over resources such as food and mates. They are known to engage in territorial disputes with neighboring groups, occasionally leading to lethal encounters.

Bonobos, by contrast, are often referred to as the “peaceful apes.” They live in matriarchal societies where females play a more dominant role, and they use social bonding to maintain harmony within their groups. Bonobos tend to resolve conflicts through physical affection, and sexual behaviors are often used as a means of defusing tension. A new study, however, found that male bonobos are just as aggressive as male chimpanzees.

The evolutionary split

Did the bonobo split from the chimpanzee, or was it the other way around? It was not so much that one species split from the other but rather that both species diverged from a shared ancestor due to geographic isolation caused by the Congo River. (“The bonobo genome compared with the chimpanzee and human genomes | nature.com”)

Chimpanzees likely evolved in more competitive, resource-scarce environments, leading to their more aggressive, hierarchical social structure. In contrast, bonobos, living in the more resource-rich environments south of the river, evolved a more cooperative and peaceful way of life. The two species took different evolutionary paths, with each developing distinct behaviors and social dynamics in response to their respective environments.