Question

Sexual reproduction greatly increases the variation that ____ could operate on

Answer 1

(1) gene frequencies may be changed by migration, gene flow from another population. (2) in small populations, gene frequencies can be changed via random sampling -- this is known as genetic drift. (3) mutation pressure and (4) non-Mendelian segregation (meiotic drive) may also change gene pools. However, by far the most important agent of evolution is (5) natural selection, which operates by differential reproductive success of individuals.

Answer 2

Natural Selection

Step-by-step explanation:

Sexual selection impart new gene combinations to the individuals by the process of gamete formation and random fertilization of gametes.

Natural selection favors the beneficial variations that impart survival and/or reproductive fitness to the individuals. This results of evolution of population consisting of better adapted individuals.

For example, natural selection favors the bacteria with antibiotic resistance genes if antibiotics are present in surroundings.