Parent age, lifespan and offspring survival: structured variation in life history in a wild population

Natural variation in neuroendocrine traits is poorly understood, despite the importance of variation in brain function and evolution. Most rodents in the temperate zones inhibit reproduction and other nonessential functions in short winter photoperiods, but some have little or no reproductive response. We tested whether genetic variability in reproductive seasonality is related to individual differences in the neuronal function of the gonadotropin-releasing hormone network, as assessed by the number and location of mature gonadotropin-releasing hormone-secreting neurons under inhibitory and excitatory photoperiods. The experiments used lines of Peromyscus leucopus previously developed by selection from a wild population. One line contained individuals reproductively inhibited by short photoperiod, and the other line contained individuals nonresponsive to short photoperiod. Expression of mature gonadotropin-releasing hormone (GnRH) immunoreactivity in the brain was detected using SMI-41 antibody in the single-labeled avidin-biotin-peroxidase-complex method. Nonresponsive mice had 50% more immunoreactive GnRH neurons than reproductively inhibited mice in both short- and long-day photoperiods. The greatest differences were in the anterior hypothalamus and preoptic areas. In contrast, we detected no significant within-lines differences in the number or location of immunoreactive GnRH neurons between photoperiod treatments. Our data indicate that high levels of genetic variation in a single wild population for a specific neuronal trait are related to phenotypic variation in a life history trait, i.e., winter reproduction. Variation in GnRH neuronal activity may underlie some of the natural reproductive and life history variation observed in wild populations of P. leucopus. Similar genetic variation in neuronal traits may be present in humans and other species.

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Effects of soybean resistance on variability in life history traits of the higher trophic level parasitoidMeteorus pulchricornis(Hymenoptera: Braconidae)

Bulletin of Entomological Research ◽

10.1017/s0007485316000407 ◽

2016 ◽

Vol 107 (1) ◽

pp. 1-8 ◽

Cited By ~ 4

Author(s):

X. Li ◽

B. Li ◽

G. Xing ◽

L. Meng

Keyword(s):

Life History ◽

Trophic Level ◽

Life History Traits ◽

Offspring Survival ◽

Lifetime Fecundity ◽

Soybean Cultivars ◽

Adult Body ◽

Meteorus Pulchricornis ◽

Soybean Resistance ◽

Resistant Genotypes

AbstractTo extrapolate the influence of plant cultivars varying in resistance levels to hosts on parasitoid life history traits, we estimated variation in parasitoid developmental and reproductive performances as a function of resistance in soybean cultivars, which were randomly chosen from a line of resistant genotypes. Our study showed that the parasitoidMeteorus pulchricornisvaried widely in offspring survival and lifetime fecundity, but varied slightly in development time and adult body size, in response to the soybean cultivars that varied in resistance to the hostSpodoptera litura. Furthermore, the variability in survival and lifetime fecundity was different between attacking the 2nd and the 4th instar host larvae, varying more in survival but less in lifetime fecundity when attacking the 4th than 2nd instar larvae. Our study provides further evidence supporting that plant resistance to herbivorous hosts have variable effects on different life history traits of higher trophic level parasitoids.

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Gene Expression Life History Markers in a Hatchery and a Wild Population of Young-of-the-Year Oncorhynchus mykiss

10.15760/etd.1444 ◽

2000 ◽

Author(s):

Ian Garrett

Keyword(s):

Gene Expression ◽

Life History ◽

Oncorhynchus Mykiss ◽

Wild Population ◽

Young Of The Year

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Number and Size of Offspring

10.1093/oso/9780198839873.003.0007 ◽

2021 ◽

pp. 115-128

Author(s):

Jeffrey A. Hutchings

Keyword(s):

Life History ◽

Clutch Size ◽

Parental Investment ◽

Adaptive Significance ◽

Offspring Size ◽

Structural Constraints ◽

Offspring Survival ◽

Trade Off ◽

Offspring Number ◽

Parental Fitness

Offspring number and size are two of the most variable life-history traits. Among species, much of this variability can be attributed to genetic, developmental, physiological, or structural constraints. Some trait combinations are not possible because of differences associated with a species’ evolutionary history. Substantial variation in propagule number and size can exist among populations of the same species, generating questions concerning the adaptive significance of this variability. The most influential models are those attributed to Lack on clutch size and to Smith and Fretwell on offspring size. Fundamental to both sets of models is a trade-off between offspring number and parental investment per offspring. When offspring survival or fitness continuously varies with offspring size, the fitness of the parent depends on both offspring size and the number of offspring of that size that the parent can produce. If offspring survival is independent of offspring size, parental fitness is maximized when individuals maximize the production of minimally sized propagules.

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Life history correlates of fecal bacterial species richness in a wild population of the blue titCyanistes caeruleus

Ecology and Evolution ◽

10.1002/ece3.1384 ◽

2015 ◽

Vol 5 (4) ◽

pp. 821-835 ◽

Cited By ~ 17

Author(s):

Clare McW. H. Benskin ◽

Glenn Rhodes ◽

Roger W. Pickup ◽

Mark C. Mainwaring ◽

Kenneth Wilson ◽

...

Keyword(s):

Life History ◽

Species Richness ◽

Wild Population ◽

Bacterial Species

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Dispersal as a source of variation in age-specific reproductive strategies in a wild population of lizards

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2015.1741 ◽

2015 ◽

Vol 282 (1820) ◽

pp. 20151741 ◽

Cited By ~ 3

Author(s):

Olivier Cotto ◽

Manuel Massot ◽

Ophélie Ronce ◽

Jean Clobert

Keyword(s):

Life History ◽

Body Condition ◽

Life History Traits ◽

Reproductive Effort ◽

Wild Population ◽

Recent Theory ◽

Offspring Sex Ratio ◽

Dispersal Syndromes ◽

Common Lizard ◽

High Investment

Dispersal syndromes describe the patterns of covariation of morphological, behavioural, and life-history traits associated with dispersal. Studying dispersal syndromes is critical to understanding the demographic and genetic consequences of movements. Among studies describing the association of life-history traits with dispersal, there is anecdotal evidence suggesting that dispersal syndromes can vary with age. Recent theory also suggests that dispersive and philopatric individuals might have different age-specific reproductive efforts. In a wild population of the common lizard ( Zootoca vivipara ), we investigated whether dispersive and philopatric individuals have different age-specific reproductive effort, survival, offspring body condition, and offspring sex ratio. Consistent with theoretical predictions, we found that young dispersive females have a higher reproductive effort than young philopatric females. Our results also suggest that the early high investment in reproduction of dispersive females trades-off with an earlier onset of senescence than in philopatric females. We further found that young dispersive females produce smaller offspring in lower body condition than do young philopatric females. Overall, our results provide empirical evidence that dispersive and philopatric individuals have different age-specific life-history traits.

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Variation in levels of luteinizing hormone and reproductive photoresponsiveness in a population of white-footed mice (Peromyscus leucopus)

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.00686.2009 ◽

2010 ◽

Vol 298 (6) ◽

pp. R1543-R1548 ◽

Cited By ~ 8

Author(s):

Paul D. Heideman ◽

Julian T. Pittman ◽

Kristin A. Schubert ◽

Christen M. R. Dubois ◽

Jennifer Bowles ◽

...

Keyword(s):

Genetic Variation ◽

Life History ◽

Luteinizing Hormone ◽

Artificial Selection ◽

Wild Population ◽

Peromyscus Leucopus ◽

Life History Strategies ◽

Life History Trait ◽

Selection Line ◽

In The Wild

Natural genetic variation in reproduction and life history strategies is a manifestation of variation in underlying regulatory neuronal and endocrine systems. A test of the hypothesis that genetic variation in luteinizing hormone (LH) level could be related to a life history trait, seasonal reproduction, was conducted on artificial selection lines from a wild-source population of white-footed mice ( Peromyscus leucopus ). Variation exists in the degree of suppression of reproduction by winter short-day photoperiods (SD) in wild-source individuals and in the laboratory population. In this population, most individuals from a photoperiod-responsive (R) artificial selection line are strongly suppressed reproductively in SD, while most individuals from a photoperiod-nonresponsive (NR) artificial selection line are only weakly reproductively suppressed in SD. We assayed levels of LH to test for genetic variation between lines that could contribute to variation in reproductive status in SD. Females from both lines were raised in long-day photoperiods (LD) or SD, ovariectomized under isoflurane anesthesia, and given estradiol implants. Levels of LH were significantly higher in the NR line than in the R line, indicating genetic variation for levels of LH. Levels of LH were higher in LD than in SD, indicating that levels of LH were sensitive to photoperiod treatment even with a controlled level of estradiol negative feedback. The results indicate that there is genetic variation in levels of LH that could be functionally important both in the laboratory in SD and in the wild population in winter. Thus genetic variation in levels of LH is a plausible causal factor determining winter reproductive phenotype in the wild population.

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