Which term describes evolution of major phenotypic changes over relatively short time periods?

• A. Macroevolution
• B. Punctuated equilibrium
• C. Adaptationism
• D. Reductionism

Answer: (A)

Macroevolution describes evolutionary changes that occur above the level of a single population, leading to major differences in form, function, or organization across lineages. It is the scale at which you see large phenotypic shifts that accumulate over time to produce new species and higher taxa. While microevolution tracks small changes within populations from generation to generation, macroevolution encompasses these large-scale differences across longer timescales. The idea of rapid changes during speciation, known as punctuated equilibrium, relates to the tempo of evolution rather than identifying the broad category of the changes themselves. Other options point to approaches or patterns rather than the scope of evolutionary change, so macroevolution best fits the description.