Neo-Darwinism is a term that is commonly used in the field of biology to describe the modern synthesis of Charles Darwin's theory of natural selection and Gregor Mendel's theory of genetics. However, there are a number of synonyms that are often used to describe this concept, including the modern synthesis, the evolutionary synthesis, and the synthetic theory of evolution. These terms all refer to the same basic idea, which is that genetic variation and natural selection are the two primary drivers of evolutionary change. While there may be subtle differences in how these terms are used, they are all fundamentally describing the same concept in biology.