Modern synthesis is a scientific theory that combines ideas from Darwin's theory of evolution and Mendelian genetics. It explains how evolution occurs through the process of natural selection acting on genetic variation within populations. This synthesis integrates various biological disciplines, including paleontology, systematics, and population genetics. The modern synthesis emphasizes that evolution is gradual and occurs over long periods. It highlights the role of mutations, gene flow, and genetic drift in shaping the genetic makeup of populations. This framework has become the foundation for understanding biological evolution and the diversity of life on Earth.