Final answer:
Microevolutionary changes within a population's genetic structure can accumulate over time leading to larger scale macroevolution, resulting in new species and other taxonomic groups. Macroevolution is evidenced in the fossil record and includes the diversification after mass extinction events. The Modern Synthesis explains how microevolutionary processes contribute to macroevolution.
Step-by-step explanation:
Understanding Microevolution and Macroevolution : Microevolutionary forces such as nonrandom mating, mutation, natural selection, and migration can lead to changes in a population's genetic structure. These are changes in allele frequencies within a population over time, reflecting population genetics. When microevolutionary changes accumulate over long periods, they can contribute to macroevolution, the broader scale of evolutionary changes seen over paleontological time. Macroevolution results in new species, genus, family, and higher-order taxonomic changes. Examples of microevolution include the development of antibiotic resistance in bacteria and color variations in a moth population due to industrial melanism. On the other hand, macroevolution is observed in the fossil record, as it encompasses changes that occur above the species level, like the diversification of the mammals after the dinosaurs went extinct. The Modern Synthesis is an important concept in evolutionary biology that combines elements of genetics with Darwin's theory of evolution by natural selection. It explains how these microevolutionary processes lead to macroevolutionary patterns observed in nature. A prime example would be Darwin's finches, which have undergone both microevolution and macroevolution, leading to speciation.