Life History

by

Charles W. Fox, Frank J. Messina

• LAST REVIEWED: 30 September 2013
• LAST MODIFIED: 30 September 2013
• DOI: 10.1093/obo/9780199830060-0016

Introduction

The life history of an organism is its pattern of survival and reproduction, along with the traits that directly affect survival and the timing or amount of reproduction. Rates of survival and reproduction can be estimated across age classes, or across different stages in organisms with complex life cycles. Life history traits include growth rate; age and size at sexual maturity; the temporal pattern or schedule of reproduction; the number, size, and sex ratio of offspring; the distribution of intrinsic or extrinsic mortality rates (e.g., patterns of senescence); and patterns of dormancy and dispersal. These traits contribute directly to age-specific survival [l(x)] and reproductive [m(x)] functions in a conventional life table constructed for demographic purposes. Compared to purely morphological, behavioral, or physiological traits, life history traits have an especially strong effect on overall fitness. They can also vary widely between closely related species or even among populations of the same species. A major goal of life history theory is to determine how natural selection gives rise to this variation. Both mathematical modeling and empirical evidence can be marshaled to explain, for example, why some organisms live very briefly while others live for decades or centuries, and why some produce just a few large offspring while others produce many thousands of small offspring.

General Overviews

Among the general treatments of life history evolution, Stearns 1992 and Roff 1992 provide an excellent starting point for exploring the basic theory and evidence. Roff 2002 revisits many of the topics covered in the author’s previous book (Roff 1992), but with a more evolutionary-genetic framework. Charnov 1993 mainly considers dimensionless ratios of life history variables that appear to be invariant across taxa (for a criticism of this perspective, see Nee, et al. 2005). More recent reviews, including the edited volume Flatt and Heyland 2011 and the book chapter Sibly 2012, have focused on physiological mechanisms underlying animal life history traits, and their associated trade-offs. Marshall, et al. 2012 reviews life history variation of marine invertebrates and Crawley 1997 provides an overview of plant life history ecology.

• Charnov, E. L. 1993. Life history invariants: Some explorations of symmetry in evolutionary ecology. Oxford: Oxford Univ. Press.

  Reviews much of the author’s previous work, and compares key life history characters across species to establish scaling laws and invariant, dimensionless ratios of trait pairs. This “symmetry” approach has been applied to explain variation in such features as sex ratios, aging, and determinate vs. indeterminate growth.

• Crawley, M. J. 1997. Life history and environment. In Plant Ecology. 2d ed. Edited by M. J. Crawley, 73–131. Oxford and Malden, MA: Blackwell Science.

  Overview of life history variation in plants. Available online (2009) by subscription.

• Flatt, T., and A. Heyland. 2011. Mechanisms of life history evolution: The genetics and physiology of life history traits and trade-offs. Oxford: Oxford Univ. Press.

  An edited volume that presents summaries for a large number of topics in life history evolution, with particular attention to genetic and physiological mechanisms underlying traits and trade-offs.

• Marshall, D. J., P. K. Krug, E. K. Kupriyanova, M. Byrne, and R. E. Emlet. 2012. The biogeography of marine invertebrate life histories. Annual Review of Ecology, Evolution and Systematics 43:97–114.

  DOI: 10.1146/annurev-ecolsys-102710-145004

  Compiles life history and geographic data for more than one thousand species of marine invertebrates, and many traits covary with temperature and local productivity. An excellent example of the utility of the comparative approach, applied here to group whose traits seem less constrained by phylogeny than is true for terrestrial species. Available online for purchase or by subscription.

• Nee, S., N. Colegrave, S. A. West, and A. Grafen. 2005. The illusion of invariant quantities in life histories. Science 309.5738: 1236–1239.

  DOI: 10.1126/science.1114488

  Argues that some dimensionless ratios of key life history appear to be “invariant” only because of a lack of independence between the variables compared (e.g., offspring-weaning mass vs. maternal mass). The authors show that, for bounded variables, even random simulations of trait values can give the impression of invariance. Available online for purchase or by subscription.

• Roff, D. A. 1992. The Evolution of life histories: Theory and analysis. New York: Chapman & Hall.

  A thorough compendium of the theory and evidence used to understand life history evolution. This tour-de-force covers both genetic and optimization approaches for virtually all important traits, and undoubtedly influenced much subsequent work in this field.

• Roff, D. A. 2002. Life history evolution. Sunderland, MA: Sinauer.

  Updates Roff 1992 and devotes more attention to quantitative-genetic modeling. This book is also organized in an interesting way; instead a sequential coverage of the usual life history traits, Roff considers the evolution of relevant traits in three types of environments: constant, stochastic, and predictable.

• Sibly, R. M. 2012. Life history. In Metabolic ecology: A scaling approach. Edited by R. M. Sibly, J. H. Brown, and A. Kodric-Brown, 57–66. Chichester, UK; and Hoboken, NJ: Wiley-Blackwell.

  DOI: 10.1002/9781119968535.ch5

  Metabolic rate, which varies with body size and temperature, influences rates of resource allocation to growth, maintenance, and reproduction. Sibly shows that many life history traits covary with mass, so that the metabolic theory of ecology can help identify broad patterns and constraints.

• Stearns, S. C. 1992. The evolution of life histories. New York: Oxford Univ. Press.

  An accessible and relatively concise introduction to the theory that is the foundation of life history studies. Provides a useful introductory discussion of the meanings of adaptation and fitness, and their application to the study of life histories.