Who is known for formulating the theory of evolution by natural selection?

The theory of evolution by natural selection is primarily associated with Charles Darwin. In the mid-19th century, Darwin proposed that species evolve over time through a process in which individuals that are better adapted to their environment are more likely to survive and reproduce. This concept revolutionized the understanding of biological diversity and the mechanisms behind it. Darwin's observations during his voyage on the HMS Beagle, particularly in the Galápagos Islands, led him to conclude that natural selection is a key driver of evolution. His publication, "On the Origin of Species," is considered one of the most influential works in the field of biology and laid the foundation for modern evolutionary theory.