The chimpanzee–human last common ancestor, or CHLCA, is the last species shared as a common ancestor by humans and chimpanzees; it represents the node point at which the line to genus Homo split from genus Pan.he last common ancestor of humans and chimps is estimated to have lived during the late Miocene, but possibly as late as Pliocene times—that is, more recent than 5.3 million years ago.