Homo habilis developed in the African savanna 2–1.5 million years ago. These ancestors were named the ‘handy humans’ because of their craftsmanship skills. Access to food became easier when tools made of stones and bones made hunting more efficeint. Homo habilis likely used tools for butchering meat, which they scavenged from more fearsome carnivores.

Based on fossil findings, Homo habilis were a taller species when compared to the southern apes. Their brain size also grew in a chain of generations, as meat was high in protein.

Based on their height and brain size, Homo habilis is considered one of the earliest members of the genus Homo. Game hunting supported developing communication between individuals.
The Homo habilis already knew how to use tools.

Homo erectus, or the upright human, lived about 1.7 million years ago. The brain size (900–1100 cm³) was twice that of that of the southern ape. The structure of the brain became more human: among other things, the frontal lobe became larger and the occipital lobe smaller. Based on the structure of the brain, it has been concluded that Homo erectus was already able to speak.

Proficiency in the manufacture of tools and weapons brought the element of planning to hunting. This increased the amount of game humans could catch and kill, therefore improving the chances of survival.

The invention of fire made it possible to cook food. Fire also helped humans to protect themselves from predators. The development of bones, brains and skills also made it possible for humans to adapt to a cooler climate. As a result, Homo erectus began to spread towards Asia and Europe.

Search the internet for images with the keywords "Homo erectus" and "Homo habilis". You will notice various different perspectives regarding the number of species, classifications, and species characteristics presented.

Homo erectus at the Vienna Museum of Natural History.