natural selection

This term is a technical scientific concept used primarily in biology and evolutionary studies. It describes a non-random process where environmental pressures determine which traits are beneficial for survival, leading to a gradual change in a population over time. It is often contrasted with genetic drift, which refers to random fluctuations in allele frequencies.

In common parlance, the phrase is frequently used as a shorthand for "survival of the fittest," though in a strict scientific context, it refers specifically to the differential reproductive success of individuals. Because it describes a singular biological mechanism, it is treated as an uncountable noun and does not have a plural form.