Evolution by natural selection arises from three conditions: individuals within a species vary, some of those variations are heritable, and organisms have more offspring than resources can support. The consequence is that individuals with relatively advantageous variations will be more likely to survive and have higher reproductive rates than those individuals with different traits.

The modern synthesis of evolutionary theory grew out of the reconciliation of Darwin’s, Wallace’s, and Mendel’s thoughts on evolution and heredity. Population genetics is a theoretical framework for describing evolutionary change in populations through the change in allele frequencies.

modern synthesis — the overarching evolutionary paradigm that took shape by the 1940s and is generally accepted today. natural selection — the greater relative survival and reproduction of individuals in a population that have favorable heritable traits, leading to evolutionary change. consequence — that individuals with relatively advantageous variations will be more likely to survive and have higher reproductive rates than those individuals with different traits. population genetics — the study of how selective forces change the allele frequencies in a population over time.