Which are forms of selection in biology?

• A. Natural selection
• B. Sexual selection
• C. Artificial selection
• D. All of the above

Answer: (D)

Selection in biology means differential reproductive success shaping populations over generations. Natural selection happens when environmental pressures favor certain heritable traits, causing those traits to become more common because individuals with them leave more offspring. Sexual selection is a special case where traits evolve because they improve mating success—traits may spread even if they don’t enhance survival, through preferences or competition for mates. Artificial selection is human-directed, choosing individuals with desirable traits for breeding, which shifts trait frequencies in the population. Together, these illustrate different ways populations evolve via differential reproduction, so all of these are forms of selection. For context, peppered moths shifted coloration due to environmental changes (natural selection), peacocks show elaborate tails because of mating preferences (sexual selection), and domestic dogs or crops illustrate human-driven selection (artificial selection).