Natural selection is a key mechanism of evolution, proposed by Charles Darwin in his theory of evolution by natural selection. It is the process by which certain traits or characteristics within a population become more common over successive generations due to their advantageous effects on the survival and reproduction of individuals carrying those traits. Natural selection occurs when individuals with certain advantageous traits are more likely to survive, reproduce, and pass on those traits to their offspring, thus increasing the frequency of those traits in the population. This process ultimately leads to the adaptation of a population to its environment, as individuals with beneficial traits are better able to thrive and pass on their genes to future generations. Natural selection is a fundamental concept in biology and plays a crucial role in shaping the diversity of life on Earth.