Evolutionary Demography of a Bruchid Beetle. II. Physiological Manipulations

Møller, H.; Smith, Robert H.; Sibly, Richard M.

doi:10.2307/2389500

Cited by 37 publications

(23 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…dung) was limited, yellow dung fly larvae of all lines grew only slightly slower to emerge earlier and smaller. This response is rare in general (Stearns & Koella, 1986) but common in species that are regularly threatened by habitat depletion (Møller et al. , 1989; Newman, 1992; Juliano & Stoffregen, 1994; Blanckenhorn, 1998, 1999).…”

Section: Discussionmentioning

confidence: 99%

Correlated responses to artificial body size selection in growth, development, phenotypic plasticity and juvenile viability in yellow dung flies

Teuschl

Reim

Blanckenhorn

2006

J of Evolutionary Biology

101

106

View full text Add to dashboard Cite

Most life history traits are positively influenced by body size, whereas disadvantages of large body size are poorly documented. To investigate presumed intrinsic costs of large size in the yellow dung fly (Scathophaga stercoraria; Diptera: Scathophagidae), we established two replicates each of three body size laboratory selection lines (small, control and large; selection on males only), and subjected flies of the resulting extended body size range to various abiotic stresses. Response to selection was symmetrical in the small and large lines (realized h2 = 0.16–0.18). After 24 generations of selection body size had changed by roughly 10%. Female size showed a correlated response to selection on male size, whereas sexual size dimorphism did not change. Development time also showed a correlated response as, similar to food limited flies, small line flies emerged earlier at smaller body size. At the lowest larval food limit possible, flies of all lines emerged at the same small body size after roughly the same development time; so overall phenotypic plasticity in body size and development time strongly increased following selection. Juvenile mortality increased markedly when food was extremely limited, large line flies showing highest mortality. Winter frost disproportionately killed large (line) flies because of their longer development times. Mortality at high temperatures was high but size‐selective effects were inconsistent. In all environments the larger males suffered more. Initial growth rate was higher for males and at unlimited food. Small line individuals of both sexes grew slowest at unlimited larval food but fastest at limited larval food, suggesting a physiological cost of fast growth. Overall, extension of the natural body size range by artificial selection revealed some otherwise cryptic intrinsic juvenile viability costs of large size, mediated by longer development or faster growth, but only in stressful environments.

show abstract

Section: Discussionmentioning

confidence: 99%

Correlated responses to artificial body size selection in growth, development, phenotypic plasticity and juvenile viability in yellow dung flies

Teuschl

Reim

Blanckenhorn

2006

J of Evolutionary Biology

101

106

View full text Add to dashboard Cite

show abstract

“…In this case, the acquisition of nutritional resources during the adult stage should affect insect fitness. There is some evidence that adult feeding influences bruchid longevity, fecundity, and egg size (Møller et al., 1989; Fox, 1993; Fox & Dingle, 1994; Takakura, 2004). However, to our knowledge, no study has addressed how the larval host affects fitness consequences of adult feeding in seed beetles.…”

Section: Introductionmentioning

confidence: 99%

Host‐associated variation in sexual size dimorphism and fitness effects of adult feeding in a bruchid beetle

Gianoli¹,

Suárez

Gonzáles

et al. 2007

Entomologia Exp Applicata

View full text Add to dashboard Cite

We studied the effect of larval host (two Convolvulus L. species, Convolvulaceae) on sexual size dimorphism and on the fitness consequences of adult feeding in the bruchid beetle Megacerus eulophus (Erichson) (Coleoptera: Bruchidae). Whereas Convolvulus chilensis Pers. occurs in low density in semiarid habitats, Convolvulus bonariensis Cav. occurs in less stressful environments and exhibits higher population density. Host plants neither differ in seed mass nor in seed nitrogen content, and there were no consistent host‐associated differences in female fitness. Consequently, host quality was considered to be similar. Sexual size dimorphism, expressed as the female:male ratio of body size, was significantly greater in C. chilensis than in C. bonariensis. A greater female size in the C. chilensis population could be selectively advantageous due to higher survival during host‐plant search in stressful environments. Female longevity was affected by food availability (starvation vs. honey‐pollen solution) and by the interaction between food availability and larval host. Fed females lived longer than starved females. This trend was found in both hosts, but it was of greater magnitude in C. chilensis than in C. bonariensis. Fecundity was significantly affected by adult feeding and larval host, and marginally affected by their interaction. Fed females laid more eggs than starved females. However, the increase in fitness of fed females was greater in C. chilensis. Results might be explained by differential selection on plasticity in life‐history traits in contrasting environments. Females in stressful environments should take a greater advantage of the transient availability of resources.

show abstract

“…However, there are many examples providing evidence for the central role of physiologically based trade-offs (Sibly and Calow 1986;Roff 1992;Stearns 1992) and their hormonal control (Ketterson andNolan 1992, 1999;Finch and Rose 1995) in life histories. For example, high reproductive effort is associated with poor moult (Hemborg and Lundberg 1998), reduced immunological status (Ots and Hõ rak 1996), and reduced investment in sexual ornamentation in birds (Gustafsson et al 1995); reduced growth in guppies (Reznick 1996); flight capability in crickets (Zera et al 1998); and longevity in insects (Møller et al 1989;Chipendale et al 1993) and birds (McCleery et al 1996). Our present aim is specifically to incorporate physiological trade-offs into a lifehistory model, based on empirical data for the house mouse, Mus musculus, to determine whether the phenomenon of life extension through calorie restriction can be satisfactorily explained as an evolutionary adaptation and what preconditions might be required.…”

mentioning

confidence: 99%

Calorie Restriction and Aging: A Life-History Analysis

Shanley¹,

Kirkwood²

2000

Evolution

269

191

View full text Add to dashboard Cite

Abstract. The disposable soma theory suggests that aging occurs because natural selection favors a strategy in which fewer resources are invested in somatic maintenance than are necessary for indefinite survival. However, laboratory rodents on calorie-restricted diets have extended life spans and retarded aging. One hypothesis is that this is an adaptive response involving a shift of resources during short periods of famine away from reproduction and toward increased somatic maintenance. The potential benefit is that the animal gains an increased chance of survival with a reduced intrinsic rate of senescence, thereby permitting reproductive value to be preserved for when the famine is over.We describe a mathematical life-history model of dynamic resource allocation that tests this idea. Senescence is modeled as a change in state that depends on the resources allocated to maintenance. Individuals are assumed to allocate the available resources to maximize the total number of descendants. The model shows that the evolutionary hypothesis is plausible and identifies two factors, both likely to exist, that favor this conclusion. These factors are that survival of juveniles is reduced during periods of famine and that the organism needs to pay an energetic ''overhead'' before any litter of offspring can be produced. If neither of these conditions holds, there is no evolutionary advantage to be gained from switching extra resources to maintenance. The model provides a basis to evaluate whether the life-extending effects of calorie-restriction might apply in other species, including humans.

show abstract

Evolutionary Demography of a Bruchid Beetle. II. Physiological Manipulations

Cited by 37 publications

References 6 publications

Correlated responses to artificial body size selection in growth, development, phenotypic plasticity and juvenile viability in yellow dung flies

Correlated responses to artificial body size selection in growth, development, phenotypic plasticity and juvenile viability in yellow dung flies

Host‐associated variation in sexual size dimorphism and fitness effects of adult feeding in a bruchid beetle

Calorie Restriction and Aging: A Life-History Analysis

Contact Info

Product

Resources

About