Orangutans can communicate about the past just like humans, new research finds
(PHYSorg.com Biology)

The evolution of language converted a defenceless naked ape into a world-dominating force. It fundamentally transformed how humans transmit information and knowledge. A large and potent component of language is our ability to communicate about things that are not here, that happened in the past, or that will happen in the future. This feature of language is known as `displaced reference`.