Individual stochasticity in the life history strategies of animals and plants

• Published in: PloS one Vol. 17; no. 9; p. e0273407
• Main Authors: Varas Enríquez, Pablo José, Van Daalen, Silke, Caswell, Hal
• Format: Journal Article
• Language: English
• Published: San Francisco Public Library of Science 23.09.2022; Public Library of Science (PLoS)
• Subjects: Age; Analysis; Animals; Biology and Life Sciences; Demography; Expected values; Fertility; Genetic aspects; Identification and classification; Life cycles; Life expectancy; Life history; Life span; Markov analysis; Markov chains; Markov processes; Medicine and Health Sciences; Methods; Offspring; Physical Sciences; Plant populations; Population; Population biology; Populations; Principal components analysis; Random variables; Research and Analysis Methods; Skewness; Stochastic analysis; Stochasticity; Variability; United States
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0273407

The life histories of organisms are expressed as rates of development, reproduction, and survival. However, individuals may experience differential outcomes for the same set of rates. Such individual stochasticity generates variance around familiar mean measures of life history traits, such as life expectancy and the reproductive number R.sub.0 . By writing life cycles as Markov chains, we calculate variance and other indices of variability for longevity, lifetime reproductive output (LRO), age at offspring production, and age at maturity for 83 animal and 332 plant populations from the Comadre and Compadre matrix databases. We find that the magnitude within and variability between populations in variance indices in LRO, especially, are surprisingly high. We furthermore use principal components analysis to assess how the inclusion of variance indices of different demographic outcomes affects life history constraints. We find that these indices, to a similar or greater degree than the mean, explain the variation in life history strategies among plants and animals.