Human evolution is often presented through a timeline of important groups, including Australopithecus, Homo habilis, Homo erectus, Neanderthals, and Homo sapiens.

Some key developments include:
Bipedalism, or walking on two legs.
Early stone-tool use.
Migration beyond Africa.
Adaptation to different environments.
The development of complex culture and symbolic behaviour.
However, human evolution was not a simple sequence in which one species directly transformed into the next. Several groups existed at overlapping times.
What do you think was the most significant milestone in human evolution: walking upright, toolmaking, migration, or cultural development?
For an overview, see:
https://thecampusreview.com/stem/7-stages-of-human-evolution/