As you know the first thing that monkeys, apes, and man have in common is that they all have backbones, so that they are all vertebrates. Many characteristics in man have arisen from living in trees. We share them with other primates, as monkeys, apes and man are known. If you suddenly found that you had to live in a tree, what do you think the most useful adaptations would be? There would bot be much point in having hoofs like a horse which help the horse to run fast. You would need to be able to hold on to the branches, however, as our hands are well able to do. If you wanted to jump branch to branch, you would have to be able to judge distances. You would need stereoscopic vision, that is, two eyes positioned at the front of your head, not at the sides as in a fish. You are unable to smell the traces of scent that a dog can, but you do have a much enlarged brain. It is the growth of the brain that has enabled man to leave the comparative safety of the trees and compete with the other ground dwelling animals that are stronger, have better hearing and sense of smell, can run faster and have warm coasts to protect them from the extremes of climate.
As you might expect, because man and apes have developed from a common ancestor, it is not easy to tell when the remains of the primates that have found are of men like apes or ape like men. But between ten and fifteen million years ago a creature which has been called a Ramapithe-cus lived in parts of Africa, Asia, and Europe. This may have been the ancestor of man and the other apes, though recent evidence suggests that our ancestor was another creature, the ancestor of the orangutan. However, the groups became increasingly diverse until the first creature that could be called human arrived. This was around four million years ago.