Cuvier, lamarck, and erasmus darwin all shared an idea of evolution; however, they all lacked:
a. the longevity necessary for evolution to take place.
b. a basic understanding of inheritance.
c. an understanding of variation.
d. a mechanism for evolution.

D- a mechanism for evolution

Explanation: The mechanism for evolution refers to the changes in allele frequencies within a single population.

There are four fundamental forces of evolution: Natural Selection, Genetic Drift, Mutations and Gene Flow

One of the main controversial issues in population genetics is concerned with the relative importance of both mechanisms in determining evolutionary changes

the answer is:

c. economic output

answer; i believe the correct answer is prefrontal cortex;