In King of Tokyo, can you get more than 1 evolution per turn?
No, you may only draw one Evolution per set of rolls.

The rulebook states:


  If a monster ends their rolls with at least 3 [hearts], they draw the top Evolution of their deck


Firstly, the term "at least 3" indicates that any number above 2 will match the condition, thus 3 or 6 or anything between will give you the same result.

Secondly since the card effect happens at the time that you end your rolls, only one card can be on top of your Evolution deck at that time.