Darwinism is a theory of biological evolution developed by Charles Darwin in the 19th century. It explains how species change over time through a process called natural selection, where individuals with traits better suited to their environment are more likely to survive and reproduce. This leads to the gradual adaptation of species to their surroundings. The core idea of Darwinism is that all living organisms share a common ancestor and that diversity arises through variations in traits. Over generations, these variations can result in the emergence of new species, contributing to the rich tapestry of life on Earth.