'Natural selection' is the process described by Charles Darwin in the 19th century, by which the physical, behavioural or cognitive characteristics of living organisms - usually attributed to genes - emerge and change in response to the environment. It is a process of variation and selection, whereby those members of a population with certain characteristics are better able to survive and reproduce, thus increasing the chance of their features, abilities or traits being passed on to the next generation. Natural selection is a complex and dynamic process, operating within a constantly changing environment and directly influenced by shifting environmental conditions, leading to evolution over time.

See also: genetic change, right hemisphere, left hemisphere, corpus callosum, split brain