Complex sentence: Humans were once thought to have evolved only from "Australopithecus afarensis", the species made famous by the fossil Lucy, but now it seems Lucy may have been sharing the woods and grass plains of prehistoric Africa with a rival.
Split into simpler sentences: Humans were once thought to have evolved only from "Australopithecus afarensis", the species made famous by the fossil Lucy. But now it seems Lucy may have been sharing the woods and grass plains of prehistoric Africa with a rival.