Final answer:
Natural selection is the logical outcome of four facts: variation within populations, heritability of traits, overproduction of offspring, and differential survival and reproduction based on advantageous traits.
Step-by-step explanation:
Natural selection is a major mechanism of evolution that acts on phenotypic variations in populations. It is the process by which individuals with traits that are better adapted to their environment are more likely to survive and reproduce, passing on their advantageous traits to future generations. Natural selection is the logical outcome of four facts: variation exists within populations, some traits are heritable, more offspring are produced than can survive, and individuals with traits that are better suited to their environment have higher survival and reproduction rates.