Science Alert: [2] The human evolutionary path is complicated. It’s almost impossible to say exactly when we modern humans became “us”. This quandary is best articulated by the famous naturalist Charles Darwin in his book The Descent of Man:
[3] “In a series of forms graduating insensibly from some apelike creature to man as he now exists, it would be impossible to fix on any definite point where the term ‘man’ ought to be used.” [4] The understanding of modern humans’ own genus, Homo, has taken many turns over the last century. Homo erectus, one of our purported ancestors, was first discovered in Indonesia in 1891 by geologist and anatomist Eugene Dubois.
[5] Since then, representatives of both this species, and other Homo, have been found across the world; for instance, in 2015, a new species of Homo, Homo naledi, was discovered in South Africa. Another new Homo species, Homo luzonensis, was found more recently in the Philippines in 2019. [6] These discoveries, combined, have led scientists to set Homo erectus’ emergence at about 1.8 million years ago – with the oldest known record coming from Dmanisi, Georgia and an important slightly later record from the East African Rift valley. [7] But our new discovery in South Africa’s Cradle of Humankind, which has just been published in Science, suggests that Homo erectus actually emerged 200,000 years earlier than we thought.

We were part of a team from South Africa, Australia, Italy and the US that discovered a Homo erectus cranium which has since been dated to almost 2 million years ago.