Because, <span>without a control, researchers would
not have anything to compare the experiment's results to. Controls are
also helpful because they permit scientists to identify possible
mistakes or errors in the experiment if the control's results are not
what they anticipated.</span>
Answer:
Organisms with heritable (genetically determined) features that help them survive and reproduce in a particular environment tend to leave more offspring than their peers. If this continues over generations, the heritable features that aid survival and reproduction will become more and more common in the population.