Endocrine Control of Life-Cycle Stages: A Constraint on Response to the Environment?

Jacobs, Jerry D.; Wingfield, John C.

doi:10.1650/0010-5422(2000)102[0035:ecolcs]2.0.co;2

Cited by 134 publications

(90 citation statements)

References 41 publications

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“…Fitness curves (expected reproductive success) for phenotypes living in environments with different degrees of environmental variation over the year are depicted in figure 1 (see also Levins 1968;Jacobs 1996;Jacobs & Wingfield 2000). If there is small environmental variation (figure 1a), this phenotype has high fitness at all times (Levins 1968).…”

Section: Life-history Stagesmentioning

confidence: 99%

“…However, if an individual has a lifespan equal to or greater than the duration of the annual cycle (as most vertebrates do), then there should be selection for changes in morphology, physiology and behaviour to maintain high fitness as the environment also changes. Jacobs & Wingfield (2000) suggested the term life-history stage to describe specific phenotypic stages within an individual at different points on the spectrum of annual environmental change resulting overall in high fitness. An extension of the phenotypic models in figure 1 can be made to life-history stages that take the place of phenotypes because here we are referring to individuals (figure 2).…”

Section: Life-history Stagesmentioning

confidence: 99%

“…winter including hibernation), vernal migration, breeding, various moults and autumnal migration (see also Jacobs & Wingfield 2000). The syndrome of traits within a life-history stage includes a suite of sub-stages that can only be expressed within that life-history stage, but can occur in various combinations and sequences Jacobs & Wingfield 2000;Wingfield 2004). There are, of course, many morphological, physiological and behavioural traits that are common to all lifehistory stages in an individual's life cycle (e.g.…”

Section: How Do We Define Life-history Stages?mentioning

confidence: 99%

“…The termination phase follows as the next life-history stage develops (from Wingfield 2004Wingfield , 2006. This overlap of developmental phase of one lifehistory stage and the termination of another results in 'superstates', which may be energetically costly Jacobs & Wingfield 2000) but usually are short lived (days to a few weeks). Superstates may be maintained for longer (including overlap of otherwise exclusive life-history stages such as moult and migration) if food supply is sufficient.…”

Section: How Do We Define Life-history Stages?mentioning

confidence: 99%

See 3 more Smart Citations

Organization of vertebrate annual cycles: implications for control mechanisms

Wingfield

2007

Phil. Trans. R. Soc. B

211

199

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The majority of vertebrates have a life span of greater than one year. Therefore individuals must be able to adapt to the annual cycle of changing conditions by adjusting morphology, physiology and behaviour. Phenotypic flexibility, in which an individual switches from one life history stage to another, is one way to maximize fitness in a changing environment. When environmental variation is low, few life history stages are needed. If environmental variation is large, there are more life history stages. Each life history stage has a characteristic set of sub-stages that can be expressed in various combinations and patterns to determine state at any point in the life of the individual. Thus individuals have a finite number of states that can be expressed over the spectrum of environmental conditions in their life spans. Life history stages have three phases-development, mature capability (when characteristic sub-stages can be expressed) and termination. Expression of a stage is time dependent (probably a minimum of one month), and termination of one stage overlaps development of the next stage. It follows that the more life history stages an individual expresses, the less flexibility it will have in timing those stages. Having fewer life history stages increases flexibility in timing, but less tolerance of variation in environmental conditions. To varying degrees it is possible to overlap mature capability of some life history stages to effectively reduce 'finite stage diversity' and maximize flexibility in timing. Theoretical ways by which this can be done, and the implications for neuroendocrine and endocrine control mechanisms are discussed. Twelve testable hypotheses are posed that relate directly to control mechanisms.

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Section: Life-history Stagesmentioning

confidence: 99%

Section: Life-history Stagesmentioning

confidence: 99%

Section: How Do We Define Life-history Stages?mentioning

confidence: 99%

Section: How Do We Define Life-history Stages?mentioning

confidence: 99%

See 2 more Smart Citations

Organization of vertebrate annual cycles: implications for control mechanisms

Wingfield

2007

Phil. Trans. R. Soc. B

211

199

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“…Although often discussed in singular terms, migration is really made up of a sequence of distinct life cycle "substages" (Ens et al, 1994;Jacobs and Wingfield, 2000). In the course of any substantial migration event, migratory birds (1) physiologically prepare for the flight (feed, gain mass, and perhaps molt), (2) become aphagic and make decisions about exact timing of departure, (3) depart and fly, and (4) arrive at their destination.…”

mentioning

confidence: 99%

Baseline Corticosterone Peaks in Shorebirds with Maximal Energy Stores for Migration: A General Preparatory Mechanism for Rapid Behavioral and Metabolic Transitions?

Piersma

Reneerkens

Ramenofsky

2000

General and Comparative Endocrinology

125

101

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Regulation of male traits by testosterone: implications for the evolution of vertebrate life histories

Hau¹

2007

BioEssays

504

350

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The negative co-variation of life-history traits such as fecundity and lifespan across species suggests the existence of ubiquitous trade-offs. Mechanistically, trade-offs result from the need to differentially allocate limited resources to traits like reproduction versus self-maintenance, with selection favoring the evolution of optimal allocation mechanism. Here I discuss the physiological (endocrine) mechanisms that underlie optimal allocation rules and how such rules evolve. The hormone testosterone may mediate life-history trade-offs due to its pleiotropic actions in male vertebrates. Conservation in the actions of testosterone in vertebrates has prompted the 'evolutionary constraint hypothesis,' which assumes that testosterone signaling mechanisms and male traits evolve as a unit. This hypothesis implies that the actions of testosterone are similar across sexes and species, and only the levels of circulating testosterone concentrations change during evolution. In contrast, the 'evolutionary potential hypothesis' proposes that testosterone signaling mechanisms and male traits evolve independently. In the latter scenario, the linkage between hormone and traits itself can be shaped by selection, leading to variation in trade-off functions. I will review recent case studies supporting the evolutionary potential hypothesis and suggest micro-evolutionary experiments to unravel the mechanistic basis of life-history evolution.

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Endocrine Control of Life-Cycle Stages: A Constraint on Response to the Environment?

Cited by 134 publications

References 41 publications

Organization of vertebrate annual cycles: implications for control mechanisms

Organization of vertebrate annual cycles: implications for control mechanisms

Baseline Corticosterone Peaks in Shorebirds with Maximal Energy Stores for Migration: A General Preparatory Mechanism for Rapid Behavioral and Metabolic Transitions?

Regulation of male traits by testosterone: implications for the evolution of vertebrate life histories

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