Instead, a researcher from the Carnegie Museum of National History in Pittsburgh says, the earliest "anthropoids" colonized Africa from Asia, The Independent reported.
"If our ideas are correct, this early colonization of Africa by anthropoids was a truly pivotal event -- one of the key points in our evolutionary history," says lead researcher Christopher Beard.
Researchers say new fossils found in central Libya dating to 39 million years ago contain a surprising number of species, including three distinct families of anthropoid primates, the British newspaper reports.
The primates' sudden appearance means either there's a huge gap in the African fossil record, or they colonized Africa from somewhere else.
Migration from Asia is the most plausible theory, the researchers say in an article in the journal Nature.
"At the time, Africa was an island continent; when these anthropoids appeared, there was nothing on that island that could compete with them," Beard says.
"It led to a period of flourishing evolutionary divergence amongst anthropoids, and one of those lineages resulted in humans.
"If our early anthropoid ancestors had not succeeded in migrating from Asia to Africa, we simply wouldn't exist."