The phenomenon that describes the ability of organisms to evolve and adapt is known as natural selection. This process, a key concept in evolutionary biology, was first outlined by Charles Darwin. Natural selection occurs when individuals with advantageous traits have higher survival and reproductive rates, leading to changes in the genetic makeup of populations over time. This adaptation allows species to better fit their environment and respond to challenges such as predators, climate, and food availability. Understanding natural selection provides insight into the diversity of life on Earth.