Answer:
John Stephen Jones states that in evolution it is necessary to have into account three factors: natural selection, mutation, and random variation.
Explanation:
These three mechanisms influence evolution and they are responsible for generating phenotypic diversity that is observed in humans.
I recommend to read his article (chapter book):
Jones, JS. (2012). Is Human Evolution Over?. In Evolution 2.0 (pp. 167-176). Springer, Berlin, Heidelberg.
