scholarly journals Age-related shapes of the cost of reproduction in vertebrates

2007 ◽  
Vol 3 (6) ◽  
pp. 674-677 ◽  
Author(s):  
G Proaktor ◽  
E.J Milner-Gulland ◽  
T Coulson
Keyword(s):  
Life History ◽  
Exponential Decay ◽  
Theoretical Method ◽  
Cost Of Reproduction ◽  
Frequent Pattern ◽  
Costs Of Reproduction ◽  
Age Related ◽  
Cost Curves ◽  
The Cost ◽  
Related Survival

The shape of the association between age and the cost of reproduction varies across species. However, it is unclear whether there are any general patterns in the way the cost of reproduction varies with life history, taxon or ecological function. Using a simple theoretical method, we identified three characteristic patterns to describe the age-related survival cost of reproduction. The most frequent pattern is an approximately exponential decay (ED) with increasing age. Two additional u-shaped patterns were identified, where the cost of reproduction was higher for young and old individuals compared with intermediate-aged individuals. The majority of these u-shaped curves suggested higher costs of reproduction at older ages (RQ), with the rest suggesting a higher cost at young ages (LQ). While predators were most likely to exhibit ED-shaped cost curves, herbivores were equally likely to exhibit ED and RQ curves; birds were likely to exhibit ED-shaped curves and mammals were split equally between ED and RQ curves. These findings suggest that there may be predictable differences in the age-related shape of the cost of reproduction between species, but further research is required to identify the mechanisms generating such differences.

Life histories of North American game birds: a reanalysis

1988 ◽  
Vol 66 (8) ◽  
pp. 1906-1912 ◽  
Author(s):  
Todd W. Arnold
Keyword(s):  
Life History ◽  
North American ◽  
Life Histories ◽  
Life History Traits ◽  
Reproductive Effort ◽  
Cost Of Reproduction ◽  
Reproductive Value ◽  
Trade Offs ◽  
Game Birds ◽  
The Cost

Recently, Zammuto (R. M. Zammuto. 1986. Can. J. Zool. 64: 2739–2749) suggested that North American game birds exhibited survival–fecundity trade-offs consistent with the "cost of reproduction" hypothesis. However, there were four serious problems with the data and the analyses that Zammuto used: (i) the species chosen for analysis ("game birds") showed little taxonomic or ecological uniformity, (ii) the measures of future reproductive value (maximum longevity) were severely biased by unequal sample sizes of band recoveries, (iii) the measures of current reproductive effort (clutch sizes) were inappropriate given that most of the birds analyzed produce self-feeding precocial offspring, and (iv) the statistical units used in the majority of analyses (species) were not statistically independent with respect to higher level taxonomy. After correcting these problems, I found little evidence of survival–fecundity trade-offs among precocial game birds, and I attribute most of the explainable variation in life-history traits of these birds to allometry, phylogeny, and geography.

scholarly journals Oleic Acid Protects Caenorhabditis Mothers From Mating-Induced Death and the Cost of Reproduction

2021 ◽  
Vol 9 ◽  
Author(s):  
Leo S. Choi ◽  
Cheng Shi ◽  
Jasmine Ashraf ◽  
Salman Sohrabi ◽  
Coleen T. Murphy
Keyword(s):  
Oleic Acid ◽  
Fat Metabolism ◽  
Dietary Supplementation ◽  
Cost Of Reproduction ◽  
Costs Of Reproduction ◽  
Short Term ◽  
C Elegans ◽  
Δ9 Desaturase ◽  
The Cost

Reproduction comes at a cost, including accelerated death. Previous studies of the interconnections between reproduction, lifespan, and fat metabolism in C. elegans were predominantly performed in low-reproduction conditions. To understand how increased reproduction affects lifespan and fat metabolism, we examined mated worms; we find that a Δ9 desaturase, FAT-7, is significantly up-regulated. Dietary supplementation of oleic acid (OA), the immediate downstream product of FAT-7 activity, restores fat storage and completely rescues mating-induced death, while other fatty acids cannot. OA-mediated lifespan restoration is also observed in C. elegans mutants suffering increased death from short-term mating, and in mated C. remanei females, indicating a conserved role of oleic acid in post-mating lifespan regulation. Our results suggest that increased reproduction can be uncoupled from the costs of reproduction from somatic longevity regulation if provided with the limiting lipid, oleic acid.

Life History Trade-Offs in Gargaphia Solani (Hemiptera: Tingidae): The Cost of Reproduction

Ecology ◽  
1982 ◽  
Vol 63 (3) ◽  
pp. 616-620 ◽  
Author(s):  
Douglas W. Tallamy ◽  
Robert F. Denno
Keyword(s):  
Life History ◽  
Cost Of Reproduction ◽  
Trade Offs ◽  
Gargaphia Solani ◽  
The Cost

scholarly journals Flowering sex ratios and costs of reproduction in gynodioecious Ocotea oblonga (Lauraceae)

2020 ◽  
Vol 131 (2) ◽  
pp. 344-355
Author(s):  
Juan C Penagos Zuluaga ◽  
Simon A Queenborough ◽  
Liza S Comita
Keyword(s):  
Reproductive Investment ◽  
Cost Of Reproduction ◽  
Costs Of Reproduction ◽  
Growth Data ◽  
Seed Fertility ◽  
Moist Forest ◽  
Biased Sex Ratio ◽  
The Cost ◽  
Ecological Differences

Abstract In gynodioecious plant species, both female and hermaphrodite individuals produce fruit, but only hermaphrodites produce pollen. Such sex-specific differences in reproductive investment may contribute to dimorphism, but the magnitude and ecological effects are still unclear, especially for gynodioecious tropical trees where collecting flowers and determining the sex is complex. We documented flowering and fruiting over three years in a natural population of Ocotea oblonga (Lauraceae) trees in a tropical moist forest, Panama. We determined sex from freshly collected flowers, counted and measured fruit, and used long-term growth data for each individual. We confirmed that O. oblonga is gynodioecious. No tree switched sex or had flowers of both sexes. The population was hermaphrodite-biased. We found no ecological differences in reproductive investment (seed, fruit, or tree size, or growth rate) between the sexes, indicating that the sex differential in the cost of reproduction is much smaller in woody gynodioecious taxa than in dioecious taxa. Females produced more fruit than hermaphrodites, which may contribute to their persistence in the population. Accordingly, and contrary to most studies of temperate gynodioecious populations, our study of a tropical tree shows no differential cost of reproduction in a hermaphrodite-biased population. Consequently, other factors such as seed fertility or herbivory could drive the biased sex ratio in this population.

scholarly journals Five reasons COVID-19 is less severe in younger age groups

2020 ◽  
Author(s):  
Paul W Turke
Keyword(s):  
Life History ◽  
Life History Theory ◽  
Age Of Onset ◽  
Age Groups ◽  
Medical Community ◽  
System Function ◽  
The Third ◽  
Immune System Function ◽  
Age Related ◽  
Younger Age

Abstract The severity of COVID-19 is age-related, with the advantage going to younger age groups. Five reasons are presented. The first two are well-known, are being actively researched by the broader medical community, and therefore are discussed only briefly here. The third, fourth, and fifth reasons derive from evolutionary life history theory, and potentially fill gaps in current understanding of why and how young and old age groups respond differently to infection with SARS-CoV-2. Age of onset of generalized somatic aging, and the timing of its progression, are identified as important causes of these disparities, as are specific antagonistic pleiotropic tradeoffs in immune system function.

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