Why do people think humans originate from monkeys?

Scientists don't think humans evolved from monkeys. They do believe that humans are more closely related to modern apes than to monkeys, but they don't believe we evolved from apes either. Humans and modern African apes both evolved from a common ancestor. The understanding of human evolution comes from the evidence presented in the fossil records and similarities found with genetic research.

Many scientists believe in Darwin's theory of evolution which states that organisms evolve over time to be able to adapt to the changing environment. He based his theory on the birds in the Galapogos Islands. There were birds on the mainland and on the island that were or used to be the same species, but the birds on the island had different features. They had these different features because of their environment. That is why some scientist believe humans evolved from monkeys, they think we learned to stand up straight and use weapons because it would ensure better survival in our environment.