What was the major transition from archaic hominins to the genus homo?

The major transition from archaic hominins to the genus homo is  Increasing brain size

Explanation:

These Archaic hominins traces were found way back before 6 million years. Though they have a similarity to homosapiens they are totally different species. Mostly traced in Africa they have variations found in the crania. The main transition is increase in their brain structure.

The evolution of humans is a topic that has to be debated on and it is contentious. DNA evidence shows that the human genus was formed from various breeding that happened between different species. The major transition occurred when the archaic hominins started breeding with humans.