Chimps are like us in many ways. Like us, chimps form cultures within their groups. A chimp culture is formed when a mommy chimp passes on the skills she
has learned from her mother to the next generation of chimps in her
group.
For example, this mommy chimp is showing her baby chimp how to fish for termites in a termite mound.
Knowing these similarities between humans and chimps, it's not surprising that we had a common ancestor. Unlike apes who took to the trees, the fossils of early human ancestors were buried in limestone that formed from shells and mud. I think that shows that there must have been a marshy terrain, and they would have had to walk on two legs to keep their heads above water.