Final answer:
The late modern synthesis is a framework in evolutionary biology that describes evolution as the change in allele frequencies within a population over time. It integrates Darwin's natural selection, Mendel's inheritance laws, and population genetics, explaining how microevolutionary changes lead to macroevolutionary patterns.
Step-by-step explanation:
The late modern synthesis (or evolutionary synthesis) is a major conceptual framework in evolutionary biology that integrates insights from Darwin's and Wallace's theory of natural selection, Mendel's laws of inheritance, and subsequent understanding of population genetics. This synthesis defines evolution as the change in allele frequencies within a population over time. Conceived in the early 20th century and solidified by the 1940s, it reconciles how microevolutionary changes (small-scale variations among individuals) lead to macroevolutionary patterns (large-scale changes responsible for the diversity of life forms). Under this framework, the Hardy-Weinberg equilibrium is a principle that states that allele frequencies in a population will remain constant in the absence of evolutionary forces—meaning no mutation, natural selection, genetic drift, or migration. However, these forces are always in play, leading to evolutionary changes and deviation from this equilibrium. The synthesis also highlights the relationship between evolution and genetics, disproving the earlier belief in blending inheritance and clarifying how natural selection works with particulate inheritance to drive evolution. The late modern synthesis continues to be foundational in evolutionary biology, underlying contemporary studies such as molecular phylogenetics. It aids our understanding of how species diversity arises, and how speciation and extinction events shape the living world. The synthesis supports the conclusion that populations and species are dynamic and continually evolving entities, shaped by genetic variation and environmental pressures.