Why did the video use the word evolve to describe the change that occurred from unicellular to multicellular life on earth

Answer: Like the unicellular organisms that came before them, multicellular organisms developed when conditions were ideal for their development. The rise of multicellular organisms allowed for Earth to develop, or evolve, a wide range of life forms.

Evolve is a term used to describe how one thing changes and become a higher form of itself so by saying that a multicellular change occurred from a unicellular change Then the correct term would be to say that it evolved