¿Como ha ocurrido la evolución humana?

The Human Revolution' emerged. It suggests there was some sudden, dramatic, genetic change around 50,000 years ago, that meant human beings, became able to think and communicate.

Explanation:

:)

synapse nervous system

the earth is thought to have been formed about 4.6 billion years ago by collisions from a cloud of hydrogen, helium, rock, ice and other materials. these were pulled together by gravity to form objects in and around earth like- asteroids and small early planets called planetesimals.

so, the best possible answer to this question will be option d- to harden materials to form different parts of earth’s layers