Answer:
There are different theories that was proposed regarding the evolution.
Step-by-step explanation:
Spontaneous generation theory states that life arises from some non-living thing or component. An experiment was carried out where it was believed that maggots arises from a piece of flesh. So, they believe that maggots (living) arises from flesh (maggots).
Theory of biogenesis states that living organisms arises from living organisms. To support the theory Pateur performed an experiment and proves that living organism arises from living organisms.