How did Gregor Mendel’s work later help explain inheritance in evolution?

A significant challenge to Charles Darwin’s theory of evolution was the lack of an adequate mechanism for inheritance. Darwin’s contemporaries favored "blending inheritance," which suggested that offspring traits were an average of their parents' characteristics. Darwin realized this was problematic because it would cause variations to be halved each generation, eventually eliminating the diversity necessary for natural selection to act upon.1

Gregor Mendel’s work provided the missing link by demonstrating that inheritance occurs through discrete, particulate factors—now known as genes—that do not blend but instead segregate and are passed on intact.12

In the 1920s and 1930s, theoretical geneticists used mathematical models to show that Mendel’s laws could explain continuous variation and that natural selection acting on these small, inherited variations could drive major evolutionary change. This integration culminated in the "synthetic theory of evolution," which combined Darwinian natural selection with Mendelian inheritance, providing a comprehensive genetic framework for understanding how populations evolve.3