The statement "humans evolved from monkeys" is a common misconception about human evolution. It is not accurate to say that humans evolved directly from modern monkeys, but rather that both humans and modern monkeys share a common evolutionary ancestor.
To understand this better, we need to delve into the concept of evolutionary relationships and the tree of life. The theory of evolution proposes that all living organisms on Earth share a common ancestry and have undergone gradual changes over millions of years. The process of evolution involves the branching and divergence of species over time.
Around 25 to 30 million years ago, there was a common ancestor that gave rise to two main lineages: the Old World monkeys (found in Africa and Asia) and the apes (found in Africa). This common ancestor is neither a modern monkey nor a modern ape but an ancient primate from which both lineages evolved separately.
In the subsequent millions of years, the ape lineage underwent further divergence, leading to the emergence of various species of apes, including gorillas, chimpanzees, bonobos, orangutans, and humans. Humans are most closely related to chimpanzees and bonobos, sharing a common ancestor with them around 6 to 8 million years ago.
On the other hand, the Old World monkey lineage continued its own evolutionary path, leading to the diverse group of modern monkeys we see today, such as baboons, macaques, and langurs.
So, while humans and modern monkeys share a common ancestor from millions of years ago, they have each evolved along separate paths since then. Humans did not evolve from any living monkey species we have today; rather, both humans and modern monkeys evolved from a common ancestor that existed in the distant past.