Life history strategies of estuarine nekton: The role of marsh macrophytes, benthic microalgae, and phytoplankton in the trophic spectrum

Estuaries ◽  
2003 ◽  
Vol 26 (2) ◽  
pp. 552-562 ◽  
Author(s):  
Steven Y. Litvin ◽  
Michael P. Weinstein
Keyword(s):  
Life History ◽  
Benthic Microalgae ◽  
Life History Strategies

scholarly journals The role of testosterone in coordinating male life history strategies: The moderating effects of the androgen receptor CAG repeat polymorphism

2017 ◽  
Vol 87 ◽  
pp. 164-175 ◽  
Author(s):  
Lee T. Gettler ◽  
Calen P. Ryan ◽  
Dan T.A. Eisenberg ◽  
Margarita Rzhetskaya ◽  
M. Geoffrey Hayes ◽  
...  
Keyword(s):  
Life History ◽  
Androgen Receptor ◽  
Cag Repeat ◽  
Life History Strategies ◽  
Moderating Effects ◽  
Repeat Polymorphism ◽  
Male Life History

scholarly journals The impact of stress on the life history strategies of African American adolescents: Cognitions, genetic moderation, and the role of discrimination.

2012 ◽  
Vol 48 (3) ◽  
pp. 722-739 ◽  
Author(s):  
Frederick X. Gibbons ◽  
Megan E. Roberts ◽  
Meg Gerrard ◽  
Zhigang Li ◽  
Steven R. H. Beach ◽  
...  
Keyword(s):  
African American ◽  
Life History ◽  
African American Adolescents ◽  
Life History Strategies ◽  
The Impact

scholarly journals Differential reproductive responses to stress reveal the role of life-history strategies within a species

2013 ◽  
Vol 280 (1771) ◽  
pp. 20132090 ◽  
Author(s):  
J. Schultner ◽  
A. S. Kitaysky ◽  
G. W. Gabrielsen ◽  
S. A. Hatch ◽  
C. Bech
Keyword(s):  
Life History ◽  
Life History Theory ◽  
Life History Strategies ◽  
Short Term ◽  
Food Shortages ◽  
Investment In Reproduction ◽  
Response To Stress ◽  
Environmental Events ◽  
Two Populations

Life-history strategies describe that ‘slow’- in contrast to ‘fast’-living species allocate resources cautiously towards reproduction to enhance survival. Recent evidence suggests that variation in strategies exists not only among species but also among populations of the same species. Here, we examined the effect of experimentally induced stress on resource allocation of breeding seabirds in two populations with contrasting life-history strategies: slow-living Pacific and fast-living Atlantic black-legged kittiwakes. We tested the hypothesis that reproductive responses in kittiwakes under stress reflect their life-history strategies. We predicted that in response to stress, Pacific kittiwakes reduce investment in reproduction compared with Atlantic kittiwakes. We exposed chick-rearing kittiwakes to a short-term (3-day) period of increased exogenous corticosterone (CORT), a hormone that is released during food shortages. We examined changes in baseline CORT levels, parental care and effects on offspring. We found that kittiwakes from the two populations invested differently in offspring when facing stress. In response to elevated CORT, Pacific kittiwakes reduced nest attendance and deserted offspring more readily than Atlantic kittiwakes. We observed lower chick growth, a higher stress response in offspring and lower reproductive success in response to CORT implantation in Pacific kittiwakes, whereas the opposite occurred in the Atlantic. Our findings support the hypothesis that life-history strategies predict short-term responses of individuals to stress within a species. We conclude that behaviour and physiology under stress are consistent with trade-off priorities as predicted by life-history theory. We encourage future studies to consider the pivotal role of life-history strategies when interpreting inter-population differences of animal responses to stressful environmental events.

scholarly journals Evolution of an asymptomatic first stage of infection in a heterogeneous population

2021 ◽  
Vol 18 (179) ◽  
pp. 20210175
Author(s):  
Chadi M. Saad-Roy ◽  
Bryan T. Grenfell ◽  
Simon A. Levin ◽  
P. van den Driessche ◽  
Ned S. Wingreen
Keyword(s):  
Population Structure ◽  
Life History ◽  
Evolutionary Dynamics ◽  
Population Heterogeneity ◽  
Life History Strategies ◽  
Specific Power ◽  
Central Feature ◽  
Evolutionarily Stable Strategies ◽  
Infectious Stage

Pathogens evolve different life-history strategies, which depend in part on differences in their host populations. A central feature of hosts is their population structure (e.g. spatial). Additionally, hosts themselves can exhibit different degrees of symptoms when newly infected; this latency is a key life-history property of pathogens. With an evolutionary-epidemiological model, we examine the role of population structure on the evolutionary dynamics of latency. We focus on specific power-law-like formulations for transmission and progression from the first infectious stage as a function of latency, assuming that the across-group to within-group transmission ratio increases if hosts are less symptomatic. We find that simple population heterogeneity can lead to local evolutionarily stable strategies (ESSs) at zero and infinite latency in situations where a unique ESS exists in the corresponding homogeneous case. Furthermore, there can exist more than one interior evolutionarily singular strategy. We find that this diversity of outcomes is due to the (possibly slight) advantage of across-group transmission for pathogens that produce fewer symptoms in a first infectious stage. Thus, our work reveals that allowing individuals without symptoms to travel can have important unintended evolutionary effects and is thus fundamentally problematic in view of the evolutionary dynamics of latency.

Life‐history strategies in salmonids: the role of physiology and its consequences

2021 ◽  
Author(s):  
Kim Birnie‐Gauvin ◽  
Xavier Bordeleau ◽  
Steven J. Cooke ◽  
Jan G. Davidsen ◽  
Sindre H. Eldøy ◽  
...  
Keyword(s):  
Life History ◽  
Life History Strategies

scholarly journals The evolution of red blood cell shape in a continental radiation of fishes

2020 ◽  
Author(s):  
Brenda Oliveira Martins ◽  
Lilian Franco-Belussi ◽  
Mayara Schueroff Siqueira ◽  
Carlos E. Fernandes ◽  
Diogo B. Provete
Keyword(s):  
Life History ◽  
Water Column ◽  
Phylogenetic Relationship ◽  
Phylogenetic Signal ◽  
Life History Strategies ◽  
Selective Pressures ◽  
Components Analysis ◽  
Dated Phylogeny ◽  
Nucleus Volume

AbstractThe size and shape of Red Blood Cells (RBC) can provide key information on life history strategies in vertebrates. However, little is known about how RBC shape evolved in response to environmental factors and the role of phylogenetic relationship. Here, we analyzed RBC morphometrics in a continental radiation of fishes testing the hypothesis that phylogenetic relationship determines species occupation of morphospace. We collected blood samples of five specimens of 15 freshwater fish species from six orders and used basic stereological methods to measure cell and nucleus area, perimeter, and diameter, cell and nucleus volume, nucleus:cytoplasm ratio, and shape factor of 50 cells per specimen. Then, we conducted a phylogenetic Principal Components Analysis using a dated phylogeny and built a phylomorphospace. To test if the phylogenetic relationship predicted the phenotypic similarity of species, we calculated multivariate phylogenetic signal. We also estimated the evolution rate of RBC shape for each node and tip using ridge regression. Finally, we tested if the position in the water column influenced RBC shape using a phylogenetic GLS. RBC shape seems to have evolved in a non-stationary way because the distribution pattern of species in the phylomorphospace is independent of the phylogeny. Accordingly, the rate of evolution for shape was highly heterogeneous, with an increase in the genus Pygocentrus. Water column position does not influence RBC shape. In conclusion, RBC shape seem to have evolved in response to multiple selective pressures independent of life history characters.

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