Natural selection is a process in which organisms better adapted to their environment tend to survive and reproduce more than those less suited. This concept, first introduced by Charles Darwin, explains how species evolve over time. Traits that enhance survival and reproduction become more common in a population, while less advantageous traits may disappear. Through natural selection, variations within a species can lead to the development of new traits. For example, in a population of birds, those with beaks better suited for accessing food sources are more likely to thrive and pass on their advantageous traits to future generations.