Developmental Thresholds and the Evolution of Reaction Norms for Age and Size at Life‐History Transitions

Day, Troy; Rowe, Locke

doi:10.1086/338989

Cited by 290 publications

(337 citation statements)

References 52 publications

(117 reference statements)

Supporting

Mentioning

302

Contrasting

Order By: Relevance

“…The first group of analyses tends to focus on single traits in a few environments (for a review see [4]) or at most two traits (e.g. [5,6]). These studies demonstrate the potential role of plasticity in generating or reducing variation in a trait among different environments.…”

Section: Introductionmentioning

confidence: 99%

Phenotypic convergence along a gradient of predation risk

et al. 2010

View full text Add to dashboard Cite

A long-standing question in ecology is whether phenotypic plasticity, rather than selection per se, is responsible for phenotypic variation among populations. Plasticity can increase or decrease variation, but most previous studies have been limited to single populations, single traits and a small number of environments assessed using univariate reaction norms. Here, examining two genetically distinct populations of Daphnia pulex with different predation histories, we quantified predator-induced plasticity among 11 traits along a fine-scale gradient of predation risk by a predator (Chaoborus) common to both populations. We test the hypothesis that plasticity can be responsible for convergence in phenotypes among different populations by experimentally characterizing multivariate reaction norms with phenotypic trajectory analysis (PTA). Univariate analyses showed that all genotypes increased age and size at maturity, and invested in defensive spikes (neckteeth), but failed to quantitatively describe whole-organism response. In contrast, PTA quantified and qualified the phenotypic strategy the organism mobilized against the selection pressure. We demonstrate, at the whole-organism level, that the two populations occupy different areas of phenotypic space in the absence of predation but converge in phenotypic space as predation threat increases.

show abstract

Section: Introductionmentioning

confidence: 99%

Phenotypic convergence along a gradient of predation risk

et al. 2010

View full text Add to dashboard Cite

show abstract

“…However, the study of environmentally induced variation in the expression of life-history traits also plays a key role in understanding how changes in the environment are filtered through the biology of the organisms into changes in population dynamics (Laakso et al 2001;Beckerman et al 2002;Lindstrom & Kokko 2002). One of the most frequently studied reaction norms is the response of size and age at maturity to changes in an individual's growth conditions (Berrigan & Charnov 1994;Twombly 1996;Morey & Reznick 2000;Day & Rowe 2002). Age and size at maturity determines not only how quickly individuals in a population can start to reproduce but also how much they can reproduce, because fecundity is often closely associated with body size (Roff 1992).…”

Section: Introductionmentioning

confidence: 99%

“…Whether the relationship between age and size at maturity is flat or negative in poor conditions will also depend upon the type of developmental threshold. A 'physical threshold' (Day & Rowe 2002) describes a minimum size or state that must be exceeded before the transition can be made. It has no effect on fecundity once it has been surpassed and therefore affects only those individuals in the population that experience poor growth conditions, generating a flat relationship between age and size at maturity in poor-growth environments.…”

Section: Introductionmentioning

confidence: 99%

“…It has no effect on fecundity once it has been surpassed and therefore affects only those individuals in the population that experience poor growth conditions, generating a flat relationship between age and size at maturity in poor-growth environments. In comparison, an 'overhead threshold' (Day & Rowe 2002) describes a proportion of an individual's total resources that must be used to undergo maturation. All individuals in the population pay this cost, but its relative effect on lifetime fecundity is less for individuals in good growth conditions.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Age and size at maturity: sex, environmental variability and developmental thresholds

Plaistow

Lapsley

Beckerman

et al. 2004

Proc. R. Soc. Lond. B

View full text Add to dashboard Cite

In most organisms, transitions between different life-history stages occur later and at smaller sizes as growth conditions deteriorate. Day and Rowe recently proposed that this pattern could be explained by the existence of developmental thresholds (minimum sizes or levels of condition below which transitions are unable to proceed). The developmental-threshold model predicts that the reaction norm of age and size at maturity will rotate in an anticlockwise manner from positive to a shallow negative slope if: (i) initial body size or condition is reduced; and/or (ii) some individuals encounter poor growth conditions at increasingly early developmental stages. We tested these predictions by rearing replicated populations of soil mites Sancassania berlesei (Michael) under different growth conditions. High-food environments produced a vertical relationship between age and size at maturity. The slope became increasingly shallow as food was reduced. By contrast, high food in the maternal environment reduced the slope of the reaction norm of age and size at maturity, whereas low food increased it. Overall, the reaction norm of age and size at maturity in S. berlesei was significantly nonlinear and differed for males and females. We describe how growth conditions, mother's environment and sex determine age and size at maturity in S. berlesei.

show abstract

“…Prolonged larval growth, however, has associated costs, such as an increasing likelihood of natural host mortality and thus failed transmission. This trade-off between transitional size and age is the basis for many models on life-cycle evolution (Rowe and Ludwig, 1991 ;Stearns, 1992 ;Berrigan and Koella, 1994 ;Abrams et al 1996 ;Day and Rowe, 2002 ;Iwasa and Wada, 2006). If a large larval size is very advantageous, then continued growth may be worth the risk, perhaps even after parasites have reached an infective stage.…”

mentioning

confidence: 99%

Acanthocephalan size and sex affect the modification of intermediate host colouration

2009

View full text Add to dashboard Cite

S U M M A R YFor trophically transmitted parasites, transitional larval size is often related to fitness. Larger parasites may have higher establishment success and/or adult fecundity, but prolonged growth in the intermediate host increases the risk of failed transmission via natural host mortality. We investigated the relationship between the larval size of an acanthocephalan (Acanthocephalus lucii) and a trait presumably related to transmission, i.e. altered colouration in the isopod intermediate host. In natural collections, big isopods harboured larger worms and had more modified (darker) abdominal colouration than small hosts. Small isopods infected with a male parasite tended to have darker abdominal pigmentation than those infected with a female, but this difference was absent in larger hosts. Female size increases rapidly with host size, so females may have more to gain than males by remaining in and growing mutually with small hosts. In experimental infections, a large total parasite volume was associated with darker host respiratory operculae, especially when it was distributed among fewer worms. Our results suggest that host pigment alteration increases with parasite size, albeit differently for male and female worms. This may be an adaptive strategy if, as parasites grow, the potential for additional growth decreases and the likelihood of host mortality increases.

show abstract

Developmental Thresholds and the Evolution of Reaction Norms for Age and Size at Life‐History Transitions

Cited by 290 publications

References 52 publications

Phenotypic convergence along a gradient of predation risk

Phenotypic convergence along a gradient of predation risk

Age and size at maturity: sex, environmental variability and developmental thresholds

Acanthocephalan size and sex affect the modification of intermediate host colouration

Contact Info

Product

Resources

About