Darwinian theories refer to the biological theories and ideas put forth by Charles Darwin about the process of evolution. Synonyms for Darwinian theories might include evolutionary biology, natural selection, survival of the fittest, or Darwinism. Additionally, the terms adaptation, speciation, and genetic drift are often used when discussing Darwinian theories and the mechanisms behind them. The idea of evolution is a foundational concept in biology and has been expanded upon and refined by scientists over the years. While Darwin's original theories were groundbreaking, today's understanding of evolution is much more advanced and includes a wide range of research and scientific inquiry.