Decrease in litter size in the shrew Crocidura suaveolens (Mammalia, Insectivora) from Corsica (France): Evolutionary response to insularity?

1997 ◽  
Vol 75 (6) ◽  
pp. 954-958 ◽  
Author(s):  
Roger Fons ◽  
Françoise Poitevin ◽  
Josette Catalan ◽  
Henri Croset
Keyword(s):  
Life History ◽  
Body Size ◽  
Litter Size ◽  
Life History Traits ◽  
Breeding Experiment ◽  
Adult Body Size ◽  
Three Generations ◽  
Evolutionary Response ◽  
Adult Body ◽  
Genetically Determined

Populations of the lesser white-toothed shrew, Crocidura suaveolens (Pallas, 1811), from Corsica show an increase in adult body size associated with a decrease in litter size. The average number of embryos in wild Corsican females is smaller (mean 2.6, n = 62) than in mainland females (mean 4.6, n = 173). A breeding experiment was run for 4 years, yielding three generations. Under standard breeding conditions, the differences between island and mainland populations were maintained and were significant (median litter size was 2 for Corsica and 5 for the mainland). These differences in life-history traits were therefore proved experimentally to be genetically determined. Hypotheses concerning the mechanisms responsible for these differences are discussed.

Geographical variations in adult body size and reproductive life history traits in an invasive anuran, Discoglossus pictus

Zoology ◽  
2016 ◽  
Vol 119 (3) ◽  
pp. 216-223 ◽  
Author(s):  
Neus Oromi ◽  
Eudald Pujol-Buxó ◽  
Olatz San Sebastián ◽  
Gustavo A. Llorente ◽  
Mohamed Aït Hammou ◽  
...  
Keyword(s):  
Life History ◽  
Body Size ◽  
Life History Traits ◽  
Adult Body Size ◽  
Discoglossus Pictus ◽  
Geographical Variations ◽  
Adult Body ◽  
Reproductive Life ◽  
Reproductive Life History

scholarly journals Do females preferentially associate with males given a better start in life?

2012 ◽  
Vol 8 (3) ◽  
pp. 362-364 ◽  
Author(s):  
Andrew T. Kahn ◽  
Julianne D. Livingston ◽  
Michael D. Jennions
Keyword(s):  
Life History ◽  
Body Size ◽  
Food Intake ◽  
Compensatory Growth ◽  
Life History Traits ◽  
Adult Life ◽  
Gambusia Holbrooki ◽  
Developmental History ◽  
Restricted Diet ◽  
Adult Body

A poor start in life owing to a restricted diet can have readily detectable detrimental consequences for many adult life-history traits. However, some costs such as smaller adult body size are potentially eliminated when individuals modify their development. For example, male mosquitofish ( Gambusia holbrooki ) that have reduced early food intake undergo compensatory growth and delay maturation so that they eventually mature at the same size as males that develop normally. But do subtle effects of a poor start persist? Specifically, does a male's developmental history affect his subsequent attractiveness to females? Females prefer to associate with larger males but, controlling for body length, we show that females spent less time in association with males that underwent compensatory growth than with males that developed normally.

scholarly journals Selection on morphological traits and fluctuating asymmetry by a fungal parasite in the yellow dung fly

2017 ◽  
Author(s):  
Wolf U. Blanckenhorn
Keyword(s):  
Body Size ◽  
Fungal Infection ◽  
Fluctuating Asymmetry ◽  
Large Body ◽  
The Body ◽  
Female Size ◽  
Adult Body Size ◽  
Scathophaga Stercoraria ◽  
Evolutionary Response ◽  
Adult Body

AbstractA Preprint reviewed and recommended by Peer Community Evolutionary Biology: http://dx.doi.org/10.24072/pci.evolbiol.100027Evidence for selective disadvantages of large body size remains scarce in general. Previous phenomenological studies of the yellow dung fly Scathophaga stercoraria have demonstrated strong positive sexual and fecundity selection on male and female size. Nevertheless, the body size of flies from a Swiss study population has declined by almost 10% from 1993 to 2009. Given substantial heritability of body size, this negative evolutionary response of an evidently positively selected trait suggests important selective factors being missed (e.g. size-selective predation or parasitism). A periodic epidemic outbreak of the fungus Entomophthora scatophagae allowedassessment of selection exerted by this parasite fatal to adult flies. Fungal infection varied over the season from ca. 50% in the cooler and more humid spring and autumn to almost 0% in summer. The probability of dying from fungal infection increased with adult body size. All infected females died before laying eggs, so there was no fungus impact on female fecundity beyond its impact on mortality. Large males showed the typical mating advantage in the field, but this pattern of positive sexual selection was nullified by fungal infection. Mean fluctuating asymmetry of paired appendages (legs, wings) did not affect the viability, fecundity or mating success of yellow dung flies in the field. This study demonstrates rare parasite-mediated disadvantages of large adult body size in the field. Reduced ability to combat parasites such as Entomophthora may be an immunity cost of large size in dung flies, although the hypothesized trade-off between fluctuating asymmetry, a presumed indicator of developmental instability and environmental stress, and immunocompetence was not found here.

Fast and slow life histories of carnivores

2011 ◽  
Vol 89 (8) ◽  
pp. 692-704 ◽  
Author(s):  
Evi Paemelaere ◽  
F. Stephen Dobson
Keyword(s):  
Life History ◽  
Body Size ◽  
Litter Size ◽  
Life Histories ◽  
Life History Traits ◽  
Life Cycles ◽  
Age At Maturity ◽  
Negatively Associated ◽  
Trade Offs ◽  
Body Sizes

The fast–slow continuum hypothesis explains life-history traits as reflecting the causal influence of mortality patterns in interaction with trade-offs among traits, particularly more reproductive effort at a cost of shorter lives. Variation among species of different body sizes produce more or less rapid life cycles (respectively, from small to large species), but the fast–slow continuum remains for birds and mammals when body-size effects are statistically removed. We tested for a fast–slow continuum in mammalian carnivores. We found the above trade-offs initially supported in a sample of 85 species. Body size, however, was strongly associated with phylogeny (ρ = 0.79), and thus we used regression techniques and independent contrasts to make statistical adjustments for both. After adjustments, the life-history trade-offs were not apparent, and few associations of life-history traits were significant. Litter size was negatively associated with age at maturity, but slightly positively associated with offspring mass. Litter size and mass were negatively associated with the length of the developmental period. Gestation length showed weak but significant negative associations with age at maturity and longevity. We conclude that carnivores, despite their wide range of body sizes and variable life histories, at best poorly exhibited a fast–slow continuum.

Life-history variation in Neomysis mercedis Holmes (Crustacea, Mysidacea) in the Fraser River estuary, British Columbia

1989 ◽  
Vol 67 (2) ◽  
pp. 363-372 ◽  
Author(s):  
N. T. Johnston ◽  
T. G. Northcote
Keyword(s):  
Life History ◽  
Body Size ◽  
River Estuary ◽  
Mortality Rates ◽  
Tidal Marshes ◽  
Adult Size ◽  
Fraser River ◽  
Life History Variation ◽  
Adult Body Size ◽  
Adult Body

The brackish-water mysid Neomysis mercedis in tidal marshes of the Fraser River produced overwintering and summer generations that differed in life-history traits. Summer generation females matured at a smaller size and produced fewer and larger eggs than the overwintering generation. Size-adjusted clutch weights were identical for summer and overwintering females. Reproductive effort was slightly lower for the overwintering females. Both generations were iteroparous, but the average frequency of breeding was higher for the overwintering generation. Seasonal variations in reproductive traits were strongly linked to fluctuations in the relative mortality rates of neonates and adults. Overwintering adults that bred in late spring had lower mortality rates than neonates, while mortality rates for summer adults were higher than those for neonates. Rearing suggested that changes in adult body size were a phenotypic response to temperature. Food availability had little additional effect on adult body size. A positive correlation between ambient water temperatures and the increase in mortality with increasing adult size provided a possible mechanism through which temperature-dependent phenotypic variation in adult body size could be selected.

scholarly journals Male competition and the evolution of mating and life-history traits in experimental populations of Aedes aegypti

2019 ◽  
Vol 286 (1904) ◽  
pp. 20190591 ◽  
Author(s):  
Alima Qureshi ◽  
Andrew Aldersley ◽  
Brian Hollis ◽  
Alongkot Ponlawat ◽  
Lauren J. Cator
Keyword(s):  
Life History ◽  
Aedes Aegypti ◽  
Mating Success ◽  
Life History Traits ◽  
Male Competition ◽  
Male Mating ◽  
Male Mating Success ◽  
Reproductive Control ◽  
Evolutionary Response ◽  
Mating Conditions

Aedes aegypti is an important disease vector and a major target of reproductive control efforts. We manipulated the opportunity for sexual selection in populations of Ae . aegypti by controlling the number of males competing for a single female. Populations exposed to higher levels of male competition rapidly evolved higher male competitive mating success relative to populations evolved in the absence of competition, with an evolutionary response visible after only five generations. We also detected correlated evolution in other important mating and life-history traits, such as acoustic signalling, fecundity and body size. Our results indicate that there is ample segregating variation for determinants of male mating competitiveness in wild populations and that increased male mating success trades-off with other important life-history traits. The mating conditions imposed on laboratory-reared mosquitoes are likely a significant determinant of male mating success in populations destined for release.

Differential effects on life history traits and body size of two anuran species inhabiting an environment related to fluorite mine

2018 ◽  
Vol 93 ◽  
pp. 36-44 ◽  
Author(s):  
Manuel A. Otero ◽  
Favio E. Pollo ◽  
Pablo R. Grenat ◽  
Nancy E. Salas ◽  
Adolfo L. Martino
Keyword(s):  
Life History ◽  
Body Size ◽  
Life History Traits ◽  
Differential Effects ◽  
Anuran Species

Grass-flower thrips of the genus Chirothrips (Thysanoptera: Thripidae), with a key to species from Iran

Zootaxa ◽  
2010 ◽  
Vol 2411 (1) ◽  
pp. 33 ◽  
Author(s):  
KAMBIZ MINAEI ◽  
LAURENCE MOUND
Keyword(s):  
Body Size ◽  
Species Group ◽  
Identification Key ◽  
Key To Species ◽  
Adult Body Size ◽  
Flower Thrips ◽  
New Synonym ◽  
Adult Body ◽  
Structural Differences

Species of the genus Chirothrips Haliday breed and pupate only within grass florets. Each larva is restricted to a single floret, and adult body size is thus presumably related to floret size. Despite this, some Chirothrips species are distinguished only on states that are related to body size. The validity of some commonly recorded members of the C. manicatus species-group, including C. africanus and C. pallidicornis, is therefore considered questionable. Character states that have been used to define the genus Agrostothrips Hood are shown to be variable, and this genus is placed as a new synonym of Chirothrips. An identification key, based on illustrated structural differences, is provided to the Chirothrips known from Iran: C. aculeatus, C. atricorpus, C. kurdistanus, C. manicatus, C. meridionalis and C. molestus.

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