natural selection

American  

[nach-er-uhl si-lek-shuhn, nach-ruhl] / ˈnætʃ ər əl sɪˈlɛk ʃən, ˈnætʃ rəl /

noun

1. the process by which forms of life having traits that better enable them to adapt to specific environmental pressures, as predators, changes in climate, or competition for food or mates, will tend to survive and reproduce in greater numbers than others of their kind, thus ensuring the perpetuation of those favorable traits in succeeding generations.

---

natural selection British  

noun

1. a process resulting in the survival of those individuals from a population of animals or plants that are best adapted to the prevailing environmental conditions. The survivors tend to produce more offspring than those less well adapted, so that the characteristics of the population change over time, thus accounting for the process of evolution

---

natural selection Scientific  

1. The process by which organisms that are better suited to their environment than others produce more offspring. As a result of natural selection, the proportion of organisms in a species with characteristics that are adaptive to a given environment increases with each generation. Therefore, natural selection modifies the originally random variation of genetic traits in a species so that alleles that are beneficial for survival predominate, while alleles that are not beneficial decrease. Originally proposed by Charles Darwin, natural selection forms the basis of the process of evolution.

2. See Notes at adaptation evolution Compare artificial selection

---

natural selection Cultural  

1. A process fundamental to evolution as described by Charles Darwin. By natural selection, any characteristic of an individual that allows it to survive to produce more offspring will eventually appear in every individual of the species, simply because those members will have more offspring.

---

Discover More

The expression survival of the fittest was used to describe this process in the nineteenth century but is not favored by modern scientists.

Etymology

Origin of natural selection

First recorded in 1855–60

Compare meaning

How does natural-selection compare to similar and commonly confused words? Explore the most common comparisons:

• natural selection vs. artificial selection
• sexual selection vs. natural selection

Example Sentences

See Examples For:

natural selection

In theory, natural selection might be expected to gradually remove traits that produce such disadvantages.

From Science Daily ● Aug. 19, 2026

That timing supports the conclusion that natural selection associated with diet, rather than the later population collapse, was responsible for the genetic pattern seen today.

From Science Daily ● Aug. 10, 2026

He argues that, as natural selection has shaped our brains and influenced our actions, the way we guide and govern behavior should be approached with our evolutionary roots in mind.

From The Wall Street Journal ● Jul. 24, 2026

While evolution lacks “intention,” the author observes, natural selection is “relentlessly, exquisitely” effective at enabling life to adapt to a range of environmental conditions.

From The Wall Street Journal ● Jul. 24, 2026

Darwin himself could scarcely have found a better example of the operation of natural selection than is provided by the way the mechanism of resistance operates.

From "Silent Spring" by Rachel Carson