scholarly journals Phenotypic selection and covariation in the life-history traits of elephant seals: heavier offspring gain a double selective advantage

Oikos ◽  
2018 ◽  
Vol 127 (6) ◽  
pp. 875-889 ◽  
Author(s):  
W. Chris Oosthuizen ◽  
Res Altwegg ◽  
Marie Nevoux ◽  
M. N. Bester ◽  
P. J. Nico de Bruyn
Keyword(s):  
Life History ◽  
Life History Traits ◽  
Phenotypic Selection ◽  
Selective Advantage ◽  
Elephant Seals

Evolution of earlyHomo: An integrated biological perspective

Science ◽  
2014 ◽  
Vol 345 (6192) ◽  
pp. 1236828 ◽  
Author(s):  
Susan C. Antón ◽  
Richard Potts ◽  
Leslie C. Aiello
Keyword(s):  
Life History ◽  
Life History Traits ◽  
Homo Sapiens ◽  
Selective Advantage ◽  
Environmental Data ◽  
Evolutionary Time ◽  
The Past ◽  
Biological Perspective ◽  
Dietary Flexibility ◽  
Hind Limbs

Integration of evidence over the past decade has revised understandings about the major adaptations underlying the origin and early evolution of the genusHomo. Many features associated withHomo sapiens, including our large linear bodies, elongated hind limbs, large energy-expensive brains, reduced sexual dimorphism, increased carnivory, and unique life history traits, were once thought to have evolved near the origin of the genus in response to heightened aridity and open habitats in Africa. However, recent analyses of fossil, archaeological, and environmental data indicate that such traits did not arise as a single package. Instead, some arose substantially earlier and some later than previously thought. From ~2.5 to 1.5 million years ago, three lineages of earlyHomoevolved in a context of habitat instability and fragmentation on seasonal, intergenerational, and evolutionary time scales. These contexts gave a selective advantage to traits, such as dietary flexibility and larger body size, that facilitated survival in shifting environments.

Prey tell: what quillback rockfish early life history traits reveal about their survival in encounters with juvenile coho salmon

2020 ◽  
Vol 650 ◽  
pp. 7-18 ◽  
Author(s):  
HW Fennie ◽  
S Sponaugle ◽  
EA Daly ◽  
RD Brodeur
Keyword(s):  
Life History ◽  
Early Life ◽  
Life History Traits ◽  
Direct Evidence ◽  
Coho Salmon ◽  
Larval Fish ◽  
Early Life History ◽  
In The Wild ◽  
Otolith Microstructure Analysis ◽  
Pelagic Juvenile

Predation is a major source of mortality in the early life stages of fishes and a driving force in shaping fish populations. Theoretical, modeling, and laboratory studies have generated hypotheses that larval fish size, age, growth rate, and development rate affect their susceptibility to predation. Empirical data on predator selection in the wild are challenging to obtain, and most selective mortality studies must repeatedly sample populations of survivors to indirectly examine survivorship. While valuable on a population scale, these approaches can obscure selection by particular predators. In May 2018, along the coast of Washington, USA, we simultaneously collected juvenile quillback rockfish Sebastes maliger from both the environment and the stomachs of juvenile coho salmon Oncorhynchus kisutch. We used otolith microstructure analysis to examine whether juvenile coho salmon were age-, size-, and/or growth-selective predators of juvenile quillback rockfish. Our results indicate that juvenile rockfish consumed by salmon were significantly smaller, slower growing at capture, and younger than surviving (unconsumed) juvenile rockfish, providing direct evidence that juvenile coho salmon are selective predators on juvenile quillback rockfish. These differences in early life history traits between consumed and surviving rockfish are related to timing of parturition and the environmental conditions larval rockfish experienced, suggesting that maternal effects may substantially influence survival at this stage. Our results demonstrate that variability in timing of parturition and sea surface temperature leads to tradeoffs in early life history traits between growth in the larval stage and survival when encountering predators in the pelagic juvenile stage.

Life History Traits in a Population of Pelobates syriacus (Boettger, 1889) from Turkey

2020 ◽  
Vol 27 (4) ◽  
pp. 195-200
Author(s):  
Ufuk Bülbül ◽  
Halime Koç ◽  
Yasemin Odabaş ◽  
Ali İhsan Eroğlu ◽  
Muammer Kurnaz ◽  
...  
Keyword(s):  
Life History ◽  
Age Structure ◽  
Life History Traits ◽  
Spadefoot Toad ◽  
Males And Females

Age structure of the eastern spadefoot toad, Pelobates syriacus from the Kızılırmak Delta (Turkey) were assessed using phalangeal skeletochronology. Snout-vent length (SVL) ranged from 42.05 to 86.63 mm in males and 34.03 to 53.27 mm in females. Age of adults ranged from 2 to 8 years in males and 3 to 5 years in females. For both sexes, SVL was significantly correlated with age. Males and females of the toads reached maturity at 2 years of age.

Hormones and Behavior

2019 ◽  
pp. 11-26
Author(s):  
Maren N. Vitousek ◽  
Laura A. Schoenle
Keyword(s):  
Life History ◽  
Life Histories ◽  
Life History Traits ◽  
Developmental Plasticity ◽  
Endocrine System ◽  
Phenotypic Traits ◽  
Social Environments ◽  
Trade Offs ◽  
And Behavior

Hormones mediate the expression of life history traits—phenotypic traits that contribute to lifetime fitness (i.e., reproductive timing, growth rate, number and size of offspring). The endocrine system shapes phenotype by organizing tissues during developmental periods and by activating changes in behavior, physiology, and morphology in response to varying physical and social environments. Because hormones can simultaneously regulate many traits (hormonal pleiotropy), they are important mediators of life history trade-offs among growth, reproduction, and survival. This chapter reviews the role of hormones in shaping life histories with an emphasis on developmental plasticity and reversible flexibility in endocrine and life history traits. It also discusses the advantages of studying hormone–behavior interactions from an evolutionary perspective. Recent research in evolutionary endocrinology has provided insight into the heritability of endocrine traits, how selection on hormone systems may influence the evolution of life histories, and the role of hormonal pleiotropy in driving or constraining evolution.

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