Natural selection acts on the __ while evolution acts on the __ individual, genus individual, population genus, species species, population

The correct answer is **individual, population**.<br /><br />Here's why:<br /><br />* **Natural selection** is the process where individuals with advantageous traits are more likely to survive and reproduce in a given environment. These traits are passed on to their offspring. The key here is that selection pressures act on the *individual*. An individual either survives and reproduces or it doesn't.<br /><br />* **Evolution** is the change in the heritable characteristics of a *population* over successive generations. While natural selection acts on individuals, the overall effect of these individual successes and failures is a change in the genetic makeup of the population. Therefore, evolution is measured at the population level.<br />