Event 29

23 million years ago

Reconstruction of an early ape, Dryopithecus, found in Eurasia and Africa.
Credit: Illustration by John Sibbick, Courtesy of John Sibbick Illustration. This image is used with permission. All rights reserved.

We belong to an advanced group of primates called the apes, who evolved in the trees of the Old World during the past 35 million years. What are apes? Apes are primates that have descended from prehistoric monkey ancestors, but differ from monkeys in having larger brains, usually larger bodies, and no tail; the arms of an ape are also highly mobile, allowing them (and us) to rotate the arm a full 360 degrees. Apes, including humans, are members of the superfamily Hominoidea or “hominoids”. These include, in increasing order of relatedness to humans, the so-called “Lesser Apes”, (the gibbons and siamangs of southeast Asia); and the “Great Apes” (the Orangutan of southeast Asia and the African apes: gorillas, chimpanzees, and bonobos or “pygmy chimpanzees”. In the trees, non-human apes are known for their swinging (brachiation) and climbing skills.

As one goes further back in the fossil record, the distinction between monkey and ape is less clear. Fossils of the genus Propliopithecus (formerly called “Aegyptopithecus”) from the Fayum desert of Egypt are considered by many authorities to be a transitional form between a monkey and an ape. These forms date from 36 to 30 million years ago. These creatures, about the size of a modern cocker spaniel, lived in the lush tropical forests of Africa, thus suggesting an African origin to all apes. The first true apes or hominoids are assigned to the genus Proconsul (22 to 14 million years ago) and are known from several sites in East Africa. These forms, represented by several species that ranged in size from that of gibbons to female gorillas, were probably fruit-eaters that lived in the tropical forests and woodland of Africa. From this stock the later apes, including humans, emerged.

Originally, scientists classified modern apes into three major families: the hylobates (gibbons and siamangs), the pongids (organgutans, gorillas, chimpanzees, and bonobos) and hominids (humans). With more recent genetic studies, especially comparative studies of DNA, it became clear that the African apes, especially chimpanzees and bonobos, are much more closely related to humans than were previously believed. A new classification system many are in favor of would put all great apes (including humans) in one family, the Hominidae. Within this family, the African apes and humans would be classified in one subfamily (the orangutans in another), and each ape in its own tribe (gorillas in one, chimpanzees and bonobos in a second, and humans in a third).

A reconstruction of a social group of the early ape, Griphopithecus.
Credit: Illustration by John Sibbick, Courtesy of John Sibbick Illustration. This image is used with permission. All rights reserved.


The fossil record shows the emergence of early apes from earlier monkey forms, and a steady progression of ape forms in Africa and Eurasia into recent times. Anatomical features such as larger body and braincase sizes, a lack of a tail, and a more mobile arm (seen in the humerus or upper arm bone.) The morphology of the teeth was similar to that seen in modern fruit-eating primates.


Believe it or not, you are an ape. Your parents are apes. Your grandparents are apes. And your prehistoric ancestors, who lived in the trees of the tropical African forests and woodlands 20 million years ago, were apes, the earliest known apes in the world. Our hominoid ancestry was characterized by tree-dwelling fruit-eat







This website contains facts about apes in comparison to other primates.

This is a good site with a lot of information about apes.

This is a concise wikipedia description of the evolution of the great apes.




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