Life history

Definition

The complete set of age- or stage-specific traits—including growth rate, age at first reproduction, number and size of offspring, reproductive frequency, and mortality schedule—that together describe how an organism allocates limited resources to survival, growth, and reproduction across its lifespan. In arthropods, life history variation often reflects trade-offs between rapid development (semelparity, high early fecundity) and extended survival (iteroparity, repeated breeding), shaped by environmental predictability, predation pressure, and resource availability.

Etymology

Example

The life history of the periodical cicada Magicicada septendecim involves 17 years of underground nymphal development followed by a brief, synchronized adult emergence and mass reproduction—an extreme example of a slow life history with predator satiation as a selective advantage.

Synonyms

• life cycle strategy
• life history strategy

Related Terms

• r/K selection theory
• Semelparity
• iteroparity
• Fecundity
• Survivorship curve
• generation time
• voltinism
• Phenology
• trade-off

Usage Notes

In entomology, 'life history' emphasizes the quantitative, evolutionary aspects of timing and allocation, whereas 'life cycle' more commonly describes the sequence of developmental stages (egg, larva, pupa, adult). Specialists distinguish 'life history traits' (measurable characteristics) from 'life history strategy' (the integrated phenotype). The term is sometimes loosely used for individual case histories in behavioral ecology, but this usage is less common for invertebrates than for vertebrate studies.