I believe man came from apes.
According to Charles Darwin's "On The Origin of Species", all living organisms (plants and animals) tend to evolve from a common descent, and due to changes in climate, topography of the Earth and arising/extinction of natural predators/preys, living organisms gradually evolve into another forms which best suits their environment and way of living.
Carolus Linnaeus, and other scientist in his time considered the apes as the closest relatives of men, compared to other animal forms - with very close anatomical and morphological relationships.
Theoretically, men have been a group of apes that have undergone a different environment, which forced them to physically "change" to adopt their environment: walking up straight to see predators, utility of hands for food collection/hunting, etc.
As a concrete example, how could we explain the finding of "human-like-ape-like" fossil remains in some parts of the earth? If traced well - with respect to the environment they were in, and the tools that have been found with them - we could see a change that we can connect from the other remains, as if they were in a ladder which changed their appearance from ape-likes to a more human form.
Source: Wikipedia.org, stocked knowledge
