Question

many ancient civilizations had named for the major constellations that we know today.this implies that

Answer 1

it implies that they were a observer of the sky and used to compare them with living things

Answer 2

This implies that humans had knowledge about the constellations since ancient times.
They used to determine the direction of sea paths in night by looking at the constellations and stars in the sky. Some civilisations used to worship them.