scholarly journals The consequences of polyandry for population viability, extinction risk and conservation

2013 ◽  
Vol 368 (1613) ◽  
pp. 20120053 ◽  
Author(s):  
Luke Holman ◽  
Hanna Kokko
Keyword(s):  
Population Dynamics ◽  
Extinction Risk ◽  
Population Level ◽  
Female Fitness ◽  
Male Care ◽  
Negative Effect ◽  
Adverse Environmental Conditions ◽  
The Cost ◽  
Cost Of Sex ◽  
Population Fitness

Polyandry, by elevating sexual conflict and selecting for reduced male care relative to monandry, may exacerbate the cost of sex and thereby seriously impact population fitness. On the other hand, polyandry has a number of possible population-level benefits over monandry, such as increased sexual selection leading to faster adaptation and a reduced mutation load. Here, we review existing information on how female fitness evolves under polyandry and how this influences population dynamics. In balance, it is far from clear whether polyandry has a net positive or negative effect on female fitness, but we also stress that its effects on individuals may not have visible demographic consequences. In populations that produce many more offspring than can possibly survive and breed, offspring gained or lost as a result of polyandry may not affect population size. Such ecological ‘masking’ of changes in population fitness could hide a response that only manifests under adverse environmental conditions (e.g. anthropogenic change). Surprisingly few studies have attempted to link mating system variation to population dynamics, and in general we urge researchers to consider the ecological consequences of evolutionary processes.

scholarly journals Timing outweighs magnitude of rainfall in shaping population dynamics of a small mammal species in steppe grassland

2021 ◽  
Vol 118 (42) ◽  
pp. e2023691118
Author(s):  
Guoliang Li ◽  
Xinrong Wan ◽  
Baofa Yin ◽  
Wanhong Wei ◽  
Xianglei Hou ◽  
...  
Keyword(s):  
Population Dynamics ◽  
Population Size ◽  
Population Level ◽  
Trophic Levels ◽  
Food Sources ◽  
Vole Population ◽  
Mammal Species ◽  
Generalist Herbivore ◽  
Negative Effect ◽  
Steppe Grassland

Climate change–induced shifts in species phenology differ widely across trophic levels, which may lead to consumer–resource mismatches with cascading population and ecosystem consequences. Here, we examined the effects of different rainfall patterns (i.e., timing and amount) on the phenological asynchrony of population of a generalist herbivore and their food sources in semiarid steppe grassland in Inner Mongolia. We conducted a 10-y (2010 to 2019) rainfall manipulation experiment in 12 0.48-ha field enclosures and found that moderate rainfall increases during the early rather than late growing season advanced the timing of peak reproduction and drove marked increases in population size through increasing the biomass of preferred plant species. By contrast, greatly increased rainfall produced no further increases in vole population growth due to the potential negative effect of the flooding of burrows. The increases in vole population size were more coupled with increased reproduction of overwintered voles and increased body mass of young-of-year than with better survival. Our results provide experimental evidence for the fitness consequences of phenological mismatches at the population level and highlight the importance of rainfall timing on the population dynamics of small herbivores in the steppe grassland environment.

scholarly journals The epidemiological consequences of immune priming

2012 ◽  
Vol 279 (1746) ◽  
pp. 4505-4512 ◽  
Author(s):  
Hannah J. Tidbury ◽  
Alex Best ◽  
Mike Boots
Keyword(s):  
Immune Response ◽  
Population Dynamics ◽  
Population Level ◽  
Low Doses ◽  
Population Stability ◽  
Invertebrate Immunity ◽  
Invertebrate Host ◽  
Immune Priming ◽  
Pathogen Persistence ◽  
Full Immunity

Exposure to low doses of pathogens that do not result in the host becoming infectious may ‘prime’ the immune response and increase protection to subsequent challenge. There is increasing evidence that such immune priming is a widespread and important feature of invertebrate host–pathogen interactions. Immune priming clearly has implications for individual hosts but will also have population-level implications. We present a susceptible–primed–infectious model—in contrast to the classic susceptible–infectious–recovered framework—to investigate the impacts of immune priming on pathogen persistence and population stability. We describe impacts of immune priming on the epidemiology of the disease in both constant and seasonal environments. A key result is that immune priming may act to destabilize population dynamics. In particular, when the proportion of individuals becoming primed rather than infected is high, but this priming does not confer full immunity, the population may be strongly destabilized through the generation of limit cycles. We discuss the implications of our model both in the context of invertebrate immunity and more widely.

scholarly journals Quantifying the gender load: can population crosses reveal interlocus sexual conflict?

2006 ◽  
Vol 361 (1466) ◽  
pp. 363-374 ◽  
Author(s):  
Tristan A.F Long ◽  
Robert Montgomerie ◽  
Adam K Chippindale
Keyword(s):  
Sperm Competition ◽  
Sexual Conflict ◽  
Population Differentiation ◽  
Population Divergence ◽  
Mating Frequency ◽  
Female Reproduction ◽  
Female Fitness ◽  
Antagonistic Coevolution ◽  
The Cost ◽  
Sexually Antagonistic Coevolution

Six sister populations of Drosophila melanogaster kept under identical environmental conditions for greater than 600 generations were reciprocally crossed to investigate the incidence of population divergence in allopatry. Population crosses directly influenced fitness, mating frequency, and sperm competition patterns. Changes in both female remating rate and the outcome of male sperm competition (P 1 , P 2 ) in response to foreign males were consistent with intersexual coevolution. Moreover, seven of the 30 crosses between foreign mates resulted in significant reductions in female fitness, whereas two resulted in significant increases, compared to local matings. This tendency for foreign males to reduce female fitness may be interpreted as evidence for either sexually antagonistic coevolution or the disruption of mutualistic interactions. However, instances in which female fitness improved via cohabitation with foreign males may better reveal sexual conflict, signalling release from the cost of interacting with locally adapted males. By this metric, female reproduction in D. melanogaster is strongly constrained by local adaptation by males, a situation that would promote antagonistic coevolution between the sexes. We conclude that sexual selection can promote population differentiation in allopatry and that sexual conflict is likely to have played a role in population differentiation in this study system.

scholarly journals Proteolytic Remodeling of Perineuronal Nets: Effects on Synaptic Plasticity and Neuronal Population Dynamics

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
P. Lorenzo Bozzelli ◽  
Seham Alaiyed ◽  
Eunyoung Kim ◽  
Sonia Villapol ◽  
Katherine Conant
Keyword(s):  
Population Dynamics ◽  
Synaptic Plasticity ◽  
Synaptic Input ◽  
Neuronal Plasticity ◽  
Population Level ◽  
Gamma Oscillations ◽  
Brain Regions ◽  
Neuronal Population ◽  
Perineuronal Nets ◽  
Perineuronal Net

The perineuronal net (PNN) represents a lattice-like structure that is prominently expressed along the soma and proximal dendrites of parvalbumin- (PV-) positive interneurons in varied brain regions including the cortex and hippocampus. It is thus apposed to sites at which PV neurons receive synaptic input. Emerging evidence suggests that changes in PNN integrity may affect glutamatergic input to PV interneurons, a population that is critical for the expression of synchronous neuronal population discharges that occur with gamma oscillations and sharp-wave ripples. The present review is focused on the composition of PNNs, posttranslation modulation of PNN components by sulfation and proteolysis, PNN alterations in disease, and potential effects of PNN remodeling on neuronal plasticity at the single-cell and population level.

scholarly journals A narrative review on HPV vaccination among boys and men

2020 ◽  
pp. 9-12
Author(s):  
Vinod K Ramani ◽  
Radheshyam Naik
Keyword(s):  
Hpv Vaccine ◽  
Hpv Vaccination ◽  
Herd Immunity ◽  
Population Level ◽  
Hpv Infection ◽  
Level Control ◽  
Anogenital Warts ◽  
Indian Context ◽  
Present Generation ◽  
The Cost

Apart from cervical cancer, Human papillomavirus (HPV) infection is associated with head and neck as well as other anogenital cancers such as vulva, vagina, anus, and penis. HPV vaccine provides specific protection against the disease and its subsequent manifestations.Vaccination programs for men tend to improve population-level control of HPV infection and directly prevent HPV related disease such as anogenital warts and oropharyngeal cancers in males. HPV vaccine does not treat existing infection or lesions/cancer and is intended for individuals before initiation fo sexual activity or any other form of exposure to HPV.Many programs across the globe do not include vaccination for boys because of the cost and little recognition of the emerging epidemic of HPV associated cancers in men. In the Indian context, as screening is not feasible for non-cervical HPV associated cancers, its incidence mostly among men will continue to rise until the present generation of vaccinated adolescents reaches their middle-age.Vaccination will reduce transmission rates and increase herd immunity. This in-turn, will prevent not just cervical cancers but also other HPV-associated malignancies among men and women.

The Effect of Profitability and Financial Leverage on Cost of Debt Moderated Earnings Management

2021 ◽  
Vol 26 (1) ◽  
pp. 35
Author(s):  
Herman Ruslim, Renny Muspyta
Keyword(s):  
Earnings Management ◽  
Cost Of Debt ◽  
Manufacturing Companies ◽  
Financial Leverage ◽  
Publicly Traded ◽  
Return On Equity ◽  
Publicly Traded Companies ◽  
Negative Effect ◽  
The Cost

This study aims to determine the effect of profitability and Financial Leverage on the Cost of Debt, and the role of Earnings Management as a moderating variable. In this study, profitability is measured by the ratio of return on equity, financial leverage is measured by the proxy debt ratio, earnings management as measured by discretionary accruals, and cost of debt is measured by the ratio of interest expense divided by the average total debt. The population in this study are publicly traded companies listed on the IDX, and the sample used is manufacturing companies listed on the IDX for the 2016-2019 period. Based on the purposive sampling method, the samples obtained were 69 manufacturing companies and 276 observations. The results showed that profitability has a negative effect on the cost of debt, while financial leverage has no effect on the cost of debt, earnings management cannot weaken the negative effect of profitability on the cost of debt and earnings management cannot weaken the negative effect of financial leverage on the cost of debt.

scholarly journals Brain size is correlated with endangerment status in mammals

2016 ◽  
Vol 283 (1825) ◽  
pp. 20152772 ◽  
Author(s):  
Eric S. Abelson
Keyword(s):  
Brain Size ◽  
Extinction Risk ◽  
Small Body ◽  
Cost Benefit ◽  
Metabolic Cost ◽  
Trade Offs ◽  
Extant Species ◽  
Body Sizes ◽  
The Cost ◽  
The Relationship

Increases in relative encephalization (RE), brain size after controlling for body size, comes at a great metabolic cost and is correlated with a host of cognitive traits, from the ability to count objects to higher rates of innovation. Despite many studies examining the implications and trade-offs accompanying increased RE, the relationship between mammalian extinction risk and RE is unknown. I examine whether mammals with larger levels of RE are more or less likely to be at risk of endangerment than less-encephalized species. I find that extant species with large levels of encephalization are at greater risk of endangerment, with this effect being strongest in species with small body sizes. These results suggest that RE could be a valuable asset in estimating extinction vulnerability. Additionally, these findings suggest that the cost–benefit trade-off of RE is different in large-bodied species when compared with small-bodied species.

scholarly journals From global to local scale: where is the best for conservation purpose?

2020 ◽  
Vol 30 (1) ◽  
pp. 183-200
Author(s):  
Elena Sulis ◽  
Gianluigi Bacchetta ◽  
Donatella Cogoni ◽  
Giuseppe Fenu
Keyword(s):  
Population Dynamics ◽  
Local Level ◽  
Demographic Data ◽  
Conservation Status ◽  
Population Level ◽  
Local Scale ◽  
Local Analysis ◽  
Vital Rates ◽  
Spanish Populations ◽  
Local Trend

AbstractDemographic analysis of plant populations represents an essential conservation tool allowing to identify the population trends both at global and at the local level. In this study, the population dynamics of Helianthemum caput-felis (Cistaceae) was investigated at the local level by monitoring six populations distributed in Sardinia, Balearic Islands and Ibero-Levantine coast (Alicante). Demographic data for each population were analysed by performing Integral Projection Models (IPMs). Our results showed that, although the local trend of the main basic demographic functions was similar, vital rates and demographic dynamics varied among populations indicating high variability. In fact, asymptotic growth rate in Spanish populations widely varied both between years and populations (some populations growth, decline or strongly decline), while Sardinian populations showed greater equilibrium or a slight increase. Also, the typical pattern of a long-lived species was not supported by the results at the local scale. These results indicated that different populations of the same species can present extremely different population dynamics and support the belief that, for conservation needs, local studies are more informative than global ones: the conservation status of H. caput-felis could notably vary at a small spatial scale and, accordingly, the conservation efforts must be planned at the population level and supported by local analysis.

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