Final answer:
The differential reproduction of genotypes, resulting from their variable fitness, is called natural selection.
Step-by-step explanation:
The differential reproduction of genotypes, resulting from their variable fitness, is called natural selection.
Natural selection is the process by which organisms with advantageous traits are more likely to survive and reproduce, passing on their genes to future generations. This leads to a gradual change in the frequency of certain traits in a population over time.
Examples of natural selection can be seen in various species, such as the evolution of antibiotic resistance in bacteria or the adaptation of finches on different Galapagos Islands.