The costs and benefits of fast living

Abstract

Growth rates play a fundamental role in many areas of biology (Q. Rev. Biol., 67, 1992, 283; Life History Invariants. Some Explorations of Symmetry in Evolutionary Biology, 1993; Philos. Trans. R. Soc. Lond. B Biol. Sci., 351, 1996Sci., 351, , 1341 Plant Strategies, Vegetation Processes, and Ecosystem Properties, 2002; Trends Ecol. Evol., 18, 2003, 471; Q. Rev. Biol., 78, 2003, 23; J. Ecol., 95, 2007, 926.) but the cost and benefits of different growth rates are notoriously difficult to quantify (Q. Rev. Biol., 72, 1997, 149; Funct. Ecol., 17, 2003, 328). This is because (1) growth rate typically declines with size and yet the most widely used growth measure -relative growth rate or RGR (conventionally measured as the log of the ratio of successive sizes divided by the time interval) -is not size-corrected and so confounds growth and size, (2) organisms have access to different amounts of resource and (3) it is essential to allow for the long-term benefits of larger size. Here we experimentally demonstrate delayed costs and benefits of rapid growth in seven plant species using a novel method to calculate size-corrected RGR. In control treatments, fast-growing plants benefited from increased reproduction the following year; however, fast-growing plants subjected to an experimental stress treatment (defoliation) showed strongly reduced survival and reproduction the following year. Importantly, when growth was estimated using the classical RGR measure, no costs or benefits were found. These results support the idea that life-history trade-offs have a dominant role in life-history and ecological theory and that the widespread failure to detect them is partly due to methodological shortcomings. (Arendt 1997(Arendt , 2003. This is because 1) growth rate typically declines with size and yet the most widely used growth measure -relative growth rate or RGR (conventionally measured as the log of the ratio of successive sizes divided by the time interval) -is not size-corrected and so confounds growth and size, 2) organisms have access to different amounts of resource and 3) it is essential to allow for the long-term benefits of larger size. Here we experimentally demonstrate delayed costs and benefits of rapid growth in seven plant species using a novel method to calculate size-corrected RGR. In control treatments, fast-growing plants benefited from increased reproduction the following year; however, fastgrowing plants subjected to an experimental stress treatment (defoliation) showed strongly reduced survival and reproduction the following year. Importantly, when growth was estimated using the classical RGR measure, no costs or benefits were found. These results support the idea that life-history trade-offs have a dominant role in life-history and ecological theory and that the widespread failure to detect them is partly due to methodological shortcomings. The Costs and Benefits of Fast

Why Is Living Fast Dangerous? Disentangling the Roles of Resistance and Tolerance of Disease

“…Previous empirical studies suggested that small/quick phenotypes are less resistant (e.g., Cable et al 2007;Cronin et al 2010b;Johnson et al 2012;Huang et al 2013), that large/slow phenotypes are more tolerant of infection (e.g., Rose et al 2009;Johnson et al 2012), and that accounting for shared host ancestry is critical for measuring HDT and its influence on epidemiological parameters (e.g., Cronin et al 2010b;Huang et al 2013). This is the first study, however, to measure the relative contributions of resistance and tolerance.…”

“…While two recent empirical studies suggest that genetically determined tolerance decreases as HDT increases (Rose et al 2009;Johnson et al 2012), evolutionary models predict that tolerance can evolve to be greatest in large/slow phenotypes, small/quick phenotypes, or intermediate phenotypes (Stowe et al 2000;Miller et al 2007). Moreover, host tolerance is also strongly influenced by environmental conditions, particularly the availability of limiting resources (Wise and Abrahamson 2005;Hall et al 2009;Cronin et al 2010a), and this environmental influence could overwhelm genetic influences.…”

Faster Is Not Always Better: Selection on Growth Rate Fluctuates across Life History and Environments

“…Other ways of modeling growth using nonlinear functions (e.g., von Bertalanffy or logistic growth curves; Rose et al 2009;Stinchcombe et al 2010) are gaining in popularity but still tend to subsume growth rates into single values that preclude exploring how selection on them may also vary ontogenetically. In our view, the so-called infinite-dimensional approach (centering on the principal components analysis of covariance matrices for traits scored at different times or ages; Kirkpatrick and Heckman 1989) offers the most elegant framework for exploring the selection and evolution of temporally varying growth dynamics (e.g., Kirkpatrick and Lofsvold 1992; see also Stinchcombe et al 2012) but remains technically challenging to implement (Kuparinen and Björklund 2011).…”

“…Growth rates are highly labile and closely tied to ecological conditions (Rose et al 2009;Stinchcombe et al 2010;Dmitriew 2011). A major framework for understanding their evolution has therefore emphasized the conditions of stress (factors that limit growth, such as resource availability or temperature) and disturbance (rates of damage or mortality) in which different growth rates should be adaptive (Grime and Hunt 1975;Case 1978;Arendt 1997).…”

“…Growth rates tend to decline with increasing size and age due to the rising costs of maintaining existing biomass or the diversion of fixed resources to other vital functions such as reproduction (West et al 2001;Rose et al 2009). Since individuals can differ in the timing, magnitude, and speed of this decline, another framework for understanding the evolution of growth rates has focused on phenotypic or genetic covariation among age-specific values (Kirkpatrick and Lofsvold 1992;Badyaev and Martin 2000), which may restrict variation in the direction of selection in much the same manner as correlations among disparate traits.…”