Imagine that you are at a party and somebody says, “If humans evolved from monkeys, then why are there still monkeys?”
Using your knowledge of biological evolution in general and the timeline of primate origins and evolution, how would you respond?
I would explain to them that we did not evolve from monkeys. That while we are biologically closely related that we did not descend from them. Monkeys and Humans actually have a distant common ancestor and some where in our distant past a group of primitive primates moved down from the trees and began to favor bipedalism or walking on two feet and slowly they evolved into us while modern monkeys are the decedents of early primates that stayed in the trees.
If someone asked that question I would first respond with how evolution works. Evolution occurs when a species gains some kind of adaptation that natural selection prefers over the previous traits of the original species. This pattern can continue until you have a lineage of different species that all live together with a common ancestor. I would then explain how this works with our relationship to monkeys. First, we did not evolve from monkeys, but we are all primates and have a common ancestor. Most likely primates appeared about 56 million years ago as euprimates and since then, prosimians, monkeys, apes and humans have all evolved from that one common ancestor. Each becoming their own branch in a family tree. Its like you are related to your great aunt but you didnt come (evolve) from her. You came (evolved) from your mother, who came (evolved) from her mother who also happened to be you great aunts sister. And then the line can continue to go back further with both you and your great aunts common ancestors.