Final answer:
Lesser apes include gibbons and siamangs, which differ from great apes in size, arboreal lifestyle, and sexual dimorphism. They have evolved from catarrhines in Africa, lack a tail, and exhibit intelligence with larger brain sizes relative to body size.
Step-by-step explanation:
The lesser apes, which include gibbons and siamangs, are part of the Hylobatidae family. Gibbons are known for their arboreal lifestyle and are smaller in contrast with the great apes. They exhibit low sexual dimorphism, but some species show different colors between sexes. With longer arms designed for brachiation, gibbons are adept at swinging through the trees. Siamangs, while also a type of lesser ape, are distinguishable by their typically larger size compared to other gibbons, and their characteristic throat pouch used for vocalizing. The great apes, on the other hand, include the genera Pan (chimpanzees and bonobos), Gorilla (gorillas), Pongo (orangutans), and Homo (humans).Apes evolved from catarrhines in Africa approximately 25 million years ago. They do not possess a tail, move through trees with agility, although many species are often found on the ground, and have larger brains relative to body size, indicating higher intelligence compared to monkeys. While the lesser apes and great apes share these characteristics, their differences are notable in terms of size, behavior, and habitat preference.