Evolutionary history of humans

 The evolutionary history of humans is the history of life on earth and how it has evolved since life first originated until the present day. 

There are three main models that have been proposed to explain how H.sapiens arose. All of the models incorporate the fact that H.erectus was the first hominin to leave Africa and inhabit Eurasia. 

1) The Multiregional model:

The Multiregional Model posits that modern human (Homo sapiens) populations arose independently from isolated populations of Homo erectus.

2) The Africa replacement model:

The Out of Africa hypothesis posits that modern humans originated in Africa, members of this species moving into the rest of the old world displacing the descendants of Homo erectus that they encountered.

3) The Hybridization model:

The Hybridization model proposes that H.sapiens evolved only once in Africaand, after dispersal out of Africa, hybridization took place between modern human and Archaic humans as their populations made contact.