Search results for "LIFE-HISTORY"
showing 9 items of 49 documents
Data from: Food makes you a target: disentangling genetic, physiological, and behavioral effects determining susceptibility to infection
2011
Genetics, physiology and behavior are all expected to influence the susceptibility of hosts to parasites. Furthermore, interactions between genetic and other factors are suggested to contribute to the maintenance of genetic polymorphism in resistance when the relative susceptibility of host genotypes is context dependent. We used a maternal sibship design and long- and short-term food deprivation treatments to test the role of family-level genetic variation, body condition, physiological state and foraging behavior on the susceptibility of Lymnaea stagnalis snails to infection by a trematode parasite that uses chemical cues to locate its hosts. In experimental exposures, we found that snail…
Data from: Pace-of-life in a social insect: behavioral syndromes in ants shift along a climatic gradient
2017
Behavioral syndromes are correlations between behavioral traits, but their selective advantage under different environmental conditions is not well understood. Here, we used the pace-of-life hypothesis to predict how behavioral syndromes could vary along climatic gradients. This hypothesis states that populations experiencing different ecological conditions should differ in suites of physiological characteristics associated with behavioral and life-history traits. We examined the persistence of behavioral syndromes at multiple levels in the ant Temnothorax longispinosus along a climatic gradient in north-eastern USA. “Across populations”, we predicted that proactive phenotypes, which show h…
Data from: Experimental evolution of an emerging plant virus in host genotypes that differ in their susceptibility to infection
2014
This study evaluates the extent to which genetic differences among host individuals from the same species conditions the evolution of a plant RNA virus. We performed a three-fold replicated evolution experiment in which Tobacco etch potyvirus isolate At17b (TEV-At17b), adapted to Arabidopsis thaliana ecotype Ler-0, was serially passaged in five genetically heterogeneous ecotypes of A. thaliana. After 15 passages we found that evolved viruses improved their fitness, showed higher infectivity and stronger virulence in their local host ecotypes. The genome of evolved lineages was sequenced and putative adaptive mutations identified. Host-driven convergent mutations have been identified. Eviden…
Maternally‐transferred thyroid hormones and life‐history variation in birds
2022
1. In vertebrates, thyroid hormones (THs) play an important role in the regulation of growth, development, metabolism, photoperiodic responses and migration. Maternally transferred THs are important for normal early-phase embryonic development when embryos are not able to produce endogenous THs. Previous studies have shown that variation in maternal THs within the physiological range can influence offspring phenotype. 2. Given the essential functions of maternal THs in development and metabolism, THs may be a mediator of life-history variation across species. 3. We tested the hypothesis that differences in life histories are associated with differences in maternal TH transfer across species…
Comparison of migratory and resident populations of brown trout reveals candidate genes for migration tendency
2018
Candidate genes associated with migration have been identified in multiple taxa: including salmonids, many of whom perform migrations requiring a series of physiological changes associated with the freshwater–saltwater transition. We screened over 5,500 SNPs for signatures of selection related to migratory behavior of brown trout Salmo trutta by focusing on ten differentially migrating freshwater populations from two watersheds (the Koutajoki and the Oulujoki). We found eight outlier SNPs potentially associated with migratory versus resident life history using multiple (≥3) outlier detection approaches. Comparison of three migratory versus resident population pairs in the Koutajoki watershe…
Frequency and Density-Dependent Selection on Life-History Strategies - A Field Experiment
2008
Negative frequency-dependence, which favors rare genotypes, promotes the maintenance of genetic variability and is of interest as a potential explanation for genetic differentiation. Density-dependent selection may also promote cyclic changes in frequencies of genotypes. Here we show evidence for both density-dependent and negative frequency-dependent selection on opposite life-history tactics (low or high reproductive effort, RE) in the bank vole (Myodes glareolus). Densitydependent selection was evident among the females with low RE, which were especially favored in low densities. Instead, both negative frequency-dependent and density-dependent selection were shown in females with high RE…
The price of safety: food deprivation in early life influences the efficacy of chemical defence in an aposematic moth
2018
Aposematism is the combination of a primary signal with a secondary defence that predators must learn to associate with one another. However, variation in the level of defence, both within and between species, is very common. As secondary defences influence individual fitness, this variation in quality and quantity requires an evolutionary explanation, particularly as it may or may not correlate with variation in primary signals. The costs of defence production are expected to play a considerable role in generating this variation, yet studies of the cost of chemical defence have focused on species that sequester their defences, while studies in species that produce them de novo are scarce. …
Heterozygote advantage and pleiotropy contribute to intraspecific color trait variability
2022
The persistence of intrapopulation phenotypic variation typically requires some form of balancing selection because drift and directional selection eventually erode genetic variation. Heterozygote advantage remains a classic explanation for the maintenance of genetic variation in the face of selection. However, examples of heterozygote advantage, other than those associated with disease resistance, are rather uncommon. Across most of its distribution, males of the aposematic moth Arctia plantaginis have two hindwing phenotypes determined by a heritable one locus-two allele polymorphism (genotypes: WW/Wy = white morph, yy = yellow morph). Using genotyped moths, we show that the presence of o…
The relationships between urbanization and bird functional traits across the streetscape
2023
Publisher Copyright: © 2023 The Authors The urbanization process leads to changes in bird communities’ taxonomic and functional compositions. Highly urbanized areas generally exhibit a reduced number of bird species sharing few functional traits. However, most urban bird studies focused on vegetation patches in temperate cities. In this study, we investigate how urban environmental attributes – noise, height of buildings, and urban vegetation characteristics – modulate species occurrences and the distribution of functional traits across the streetscape of a tropical metropolis. We predicted diverse trait-environment relationships, but that highly urbanized contexts (e.g., noisy streets with…