Question

darwin explained that evolution occurred by a mechanism called choose. the environment determines the choose of an organism, which depends on choose that help the organism survive and reproduce.

Explanation:

Answer:

First blank: natural selection
Second blank: fitness
Third blank: traits

(Note: The first blank is the mechanism of evolution Darwin proposed, the second is the measure of an organism's ability to survive and reproduce, and the third refers to the characteristics that aid in survival.)