why does the discovery of lucy and ardi make many scientists think that humans started in africa?

Lucy is the name given to a fossilized skeleton of a female of the species Australopithecus afarensis. These remains were found in 1974, and they were the oldest remains of hominids discovered at that time. However, in 2009, scientists discovered the skeleton of a hominid known as Ardi, which is a member of the Ardipithecus ramidus. This skeleton is 4.4 million years old. or 1.2 million years older than Lucy. Both of these were found in Africa, which suggests that humans probably started in Africa.

i would go with the last one