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

That was assumed to be the result of a natural selection.

From Barron's • Feb. 26, 2026

The theoretical approach, which studies human behavior, cognition and emotions as products of natural selection, depicts relationship formation as sales-like, highly gendered and strategy-based.

From Los Angeles Times • Feb. 12, 2026

Lo wants to use a kind of computer-accelerated natural selection to spur the development of better AI models.

From The Wall Street Journal • Feb. 9, 2026

Under this view, mutations are usually neither helpful nor harmful, allowing them to spread quietly without being strongly favored or rejected by natural selection.

From Science Daily • Dec. 24, 2025

For a variant of gross-beaked finch to appear on a Galápagos island by natural selection, two seemingly contradictory facts had to be simultaneously true.

From "The Gene" by Siddhartha Mukherjee