scholarly journals Shared environmental effects bias phenotypic estimates of assortative mating in a wild bird

2018 ◽  
Vol 14 (7) ◽  
pp. 20180106 ◽  
Author(s):  
Barbara Class ◽  
Jon E. Brommer
Keyword(s):  
Assortative Mating ◽  
Wild Populations ◽  
Morphometric Traits ◽  
Shared Environmental Effect ◽  
Males And Females ◽  
Statistical Approaches ◽  
Residual Covariance ◽  
Blue Tits ◽  
Term Data

Assortative mating is pervasive in wild populations and commonly described as a positive correlation between the phenotypes of males and females across mated pairs. This correlation is often assumed to reflect non-random mate choice based on phenotypic similarity. However, phenotypic resemblance between mates can also arise when their traits respond plastically to a shared environmental effect creating a (within-pair) residual correlation in traits. Using long-term data collected in pairs of wild blue tits and a covariance partitioning approach, we empirically demonstrate that such residual covariance indeed exists and can generate phenotypic correlations (or mask assortative mating) in behavioural and morphometric traits. These findings (i) imply that residual covariance is likely to be common and bias phenotypic estimates of assortative mating, which can have consequences for evolutionary predictions, (ii) call for the use of rigorous statistical approaches in the study of assortative mating, and (iii) show the applicability of one of these approaches in a common study system.

scholarly journals Gregariousness, foraging effort, and affiliative interactions in lactating bonobos and chimpanzees

2020 ◽  
Author(s):  
Sean M Lee ◽  
Gottfried Hohmann ◽  
Elizabeth V Lonsdorf ◽  
Barbara Fruth ◽  
Carson M Murray
Keyword(s):  
Social Interaction ◽  
Travel Time ◽  
Feeding Competition ◽  
Wild Populations ◽  
East African ◽  
Foraging Effort ◽  
African Populations ◽  
Lactating Females ◽  
Term Data

Abstract Fission–fusion dynamics have evolved in a broad range of animal taxa and are thought to allow individuals to mitigate feeding competition. While this is the principal benefit of fission–fusion, few studies have evaluated its costs. We compared gregariousness, foraging budgets, and social budgets between lactating bonobos and chimpanzees from wild populations to evaluate potential costs. Both species exhibit fission–fusion dynamics, but chimpanzees, particularly in East African populations, appear to experience higher feeding competition than bonobos. We expected lactating chimpanzees to be less gregarious than lactating bonobos; reduced gregariousness should allow lactating chimpanzees to mitigate the costs of higher feeding competition without requiring more foraging effort. However, we expected the reduced gregariousness of lactating chimpanzees to limit their time available for affiliative interactions. Using long-term data from LuiKotale bonobos and Gombe chimpanzees, we found that lactating chimpanzees were indeed less gregarious than lactating bonobos, while feeding and travel time did not differ between species. Contrary to our predictions, lactating females did not differ in social interaction time, and lactating chimpanzees spent proportionately more time interacting with individuals other than their immature offspring. Our results indicate that lactating chimpanzees can maintain social budgets comparable to lactating bonobos despite reduced gregariousness and without incurring additional foraging costs. We discuss potential explanations for why lactating bonobos are more gregarious.

scholarly journals An R package for an integrated evaluation of statistical approaches to cancer incidence projection

2020 ◽  
Author(s):  
Maximilian Knoll ◽  
Jennifer Furkel ◽  
Jürgen Debus ◽  
Amir Abdollahi ◽  
André Karch ◽  
...  
Keyword(s):  
Cancer Incidence ◽  
Empirical Evaluation ◽  
R Package ◽  
Cancer Registries ◽  
Additive Models ◽  
Operating Characteristics ◽  
Complex Models ◽  
Statistical Approaches ◽  
Term Data

Abstract Background: Projection of future cancer incidence is an important task in cancer epidemiology. The results are of interest also for biomedical research and public health policy. Age-Period-Cohort (APC) models, usually based on long-term cancer registry data (>20yrs), are established for such projections. In many countries (including Germany), however, nationwide long-term data are not yet available. General guidance on statistical approaches for projections using rather short-term data is challenging and software to enable researchers to easily compare approaches is lacking. Methods: To enable a comparative analysis of the performance of statistical approaches to cancer incidence projection, we developed an R package (incAnalysis), supporting in particular Bayesian models fitted by Integrated Nested Laplace Approximations (INLA). Its use is demonstrated by an extensive empirical evaluation of operating characteristics (bias, coverage and precision) of potentially applicable models differing by complexity. Observed long-term data from three cancer registries (SEER-9, NORDCAN, Saarland) was used for benchmarking. Results: Overall, coverage was high (mostly >90%) for Bayesian APC models (BAPC), whereas less complex models showed differences in coverage dependent on projection-period. Intercept-only models yielded values below 20% for coverage. Bias increased and precision decreased for longer projection periods (>15 years) for all except intercept-only models. Precision was lowest for complex models such as BAPC models, generalized additive models with multivariate smoothers and generalized linear models with age x period interaction effects. Conclusion: The incAnalysis R package allows a straightforward comparison of cancer incidence rate projection approaches. Further detailed and targeted investigations into model performance in addition to the presented empirical results are recommended to derive guidance on appropriate statistical projection methods in a given setting.

scholarly journals Older mothers produce more successful daughters

2020 ◽  
Vol 117 (9) ◽  
pp. 4809-4814 ◽  
Author(s):  
Svenja B. Kroeger ◽  
Daniel T. Blumstein ◽  
Kenneth B. Armitage ◽  
Jane M. Reid ◽  
Julien G. A. Martin
Keyword(s):  
Reproductive Success ◽  
Life History Traits ◽  
Lifetime Reproductive Success ◽  
Wild Populations ◽  
Substantial Variation ◽  
Older Mothers ◽  
Lower Elevation ◽  
In The Wild ◽  
Term Data

Annual reproductive success and senescence patterns vary substantially among individuals in the wild. However, it is still seldom considered that senescence may not only affect an individual but also affect age-specific reproductive success in its offspring, generating transgenerational reproductive senescence. We used long-term data from wild yellow-bellied marmots (Marmota flaviventer) living in two different elevational environments to quantify age-specific reproductive success of daughters born to mothers differing in age. Contrary to prediction, daughters born to older mothers had greater annual reproductive success on average than daughters born to younger mothers, and this translated into greater lifetime reproductive success. However, in the favorable lower elevation environment, daughters born to older mothers also had greater age-specific decreases in annual reproductive success. In the harsher higher elevation environment on the other hand, daughters born to older mothers tended to die before reaching ages at which such senescent decreases could be observed. Our study highlights the importance of incorporating environment-specific transgenerational parent age effects on adult offspring age-specific life-history traits to fully understand the substantial variation observed in senescence patterns in wild populations.

scholarly journals Demographic and genetic factors in the recovery or demise ofex situpopulations following a severe bottleneck in fifteen species of Hawaiian tree snails

PeerJ ◽  
2015 ◽  
Vol 3 ◽  
pp. e1406 ◽  
Author(s):  
Melissa R. Price ◽  
David Sischo ◽  
Mark-Anthony Pascua ◽  
Michael G. Hadfield
Keyword(s):  
Life History Traits ◽  
Human Impacts ◽  
Ex Situ ◽  
Wild Populations ◽  
Captive Populations ◽  
Introduced Predators ◽  
In Captivity ◽  
Term Data

Wild populations of endangered Hawaiian tree snails have declined precipitously over the last century due to introduced predators and other human impacts. Life history traits, such as very low fecundity (<5 offspring per year across taxa) and maturity at approximately four years of age have made recovery difficult. Conservation efforts such asin situpredator-free enclosures may increase survival to maturity by protecting offspring from predation, but no long-term data existed prior to this study demonstrating the demographic and genetic parameters necessary to maintain populations within those enclosures. We evaluated over 20 years of evidence for the dynamics of survival and extinction in captiveex situpopulations of Hawaiian tree snails established from wild-collected individuals. From 1991 to 2006, small numbers of snails (<15) from fifteen species were collected from the wild to initiate captive-reared populations as a hedge against extinction. This small number of founders resulted in a severe bottleneck in each of the captive-reared populations. We identified key demographic parameters that predicted population recovery from this bottleneck. Species with captive populations that produced between two and four offspring per adult per year and had 20–50% of those offspring survive to maturity recovered to numbers above 100 individuals, and maintained viable populations following a decline that occurred between 2009 and 2014. Those populations that had less than two offspring per adult per year and less than 20% survival to maturity did not reach 100 individuals in captivity, and many of these populations died out during the recent decline. We suggest that small reductions in fitness may contribute to extirpation in taxa with inherently low fecundity, by keeping populations below a threshold number essential to long-term recovery. Futureex situpopulations should be founded with no less than 15 adults, and maintained in conditions closely approximating the temperature and humidity of source locations to optimize fitness. Permanent translocations of wild populations for conservation purposes will be more likely to succeed with greater than 100 adults, and should be limited to locations with a similar climate to source locations.

scholarly journals An R package for an integrated evaluation of statistical approaches to cancer incidence projection

2020 ◽  
Author(s):  
Maximilian Knoll ◽  
Jennifer Furkel ◽  
Jürgen Debus ◽  
Amir Abdollahi ◽  
André Karch ◽  
...  
Keyword(s):  
Cancer Incidence ◽  
Empirical Evaluation ◽  
R Package ◽  
Cancer Registries ◽  
Additive Models ◽  
Operating Characteristics ◽  
Complex Models ◽  
Statistical Approaches ◽  
Term Data

Abstract Background: Projection of future cancer incidence is an important task in cancer epidemiology. The results are of interest also for biomedical research and public health policy. Age-Period-Cohort (APC) models, usually based on long-term cancer registry data (>20yrs), are established for such projections. In many countries (including Germany), however, nationwide long-term data are not yet available. It is unclear which statistical approach should be recommended for projections using rather short-term data. Methods: To enable a comparative analysis of the performance of statistical approaches to cancer incidence projection, we developed an R package (incAnalysis), supporting in particular Bayesian models fitted by Integrated Nested Laplace Approximations (INLA). Its use is demonstrated by an extensive empirical evaluation of operating characteristics (bias, coverage and precision) of potentially applicable models differing by complexity. Observed long-term data from three cancer registries (SEER-9, NORDCAN, Saarland) was used for benchmarking. Results: Overall, coverage was high (mostly >90%) for Bayesian APC models (BAPC), whereas less complex models showed differences in coverage dependent on projection-period. Intercept-only models yielded values below 20% for coverage. Bias increased and precision decreased for longer projection periods (>15 years) for all except intercept-only models. Precision was lowest for complex models such as BAPC models, generalized additive models with multivariate smoothers and generalized linear models with age x period interaction effects. Conclusion: The incAnalysis R package allows a straightforward comparison of cancer incidence rate projection approaches. Further detailed and targeted investigations into model performance in addition to the presented empirical results are recommended to derive guidance on appropriate statistical projection methods in a given setting.

scholarly journals An R package for an integrated evaluation of statistical approaches to cancer incidence projection

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Maximilian Knoll ◽  
Jennifer Furkel ◽  
Jürgen Debus ◽  
Amir Abdollahi ◽  
André Karch ◽  
...  
Keyword(s):  
Cancer Incidence ◽  
Empirical Evaluation ◽  
R Package ◽  
Cancer Registries ◽  
Additive Models ◽  
Operating Characteristics ◽  
Complex Models ◽  
Statistical Approaches ◽  
Term Data

Abstract Background Projection of future cancer incidence is an important task in cancer epidemiology. The results are of interest also for biomedical research and public health policy. Age-Period-Cohort (APC) models, usually based on long-term cancer registry data (> 20 yrs), are established for such projections. In many countries (including Germany), however, nationwide long-term data are not yet available. General guidance on statistical approaches for projections using rather short-term data is challenging and software to enable researchers to easily compare approaches is lacking. Methods To enable a comparative analysis of the performance of statistical approaches to cancer incidence projection, we developed an R package (incAnalysis), supporting in particular Bayesian models fitted by Integrated Nested Laplace Approximations (INLA). Its use is demonstrated by an extensive empirical evaluation of operating characteristics (bias, coverage and precision) of potentially applicable models differing by complexity. Observed long-term data from three cancer registries (SEER-9, NORDCAN, Saarland) was used for benchmarking. Results Overall, coverage was high (mostly > 90%) for Bayesian APC models (BAPC), whereas less complex models showed differences in coverage dependent on projection-period. Intercept-only models yielded values below 20% for coverage. Bias increased and precision decreased for longer projection periods (> 15 years) for all except intercept-only models. Precision was lowest for complex models such as BAPC models, generalized additive models with multivariate smoothers and generalized linear models with age x period interaction effects. Conclusion The incAnalysis R package allows a straightforward comparison of cancer incidence rate projection approaches. Further detailed and targeted investigations into model performance in addition to the presented empirical results are recommended to derive guidance on appropriate statistical projection methods in a given setting.

The effect of sex ratio on size-assortative mating in two explosively breeding anurans

2015 ◽  
Vol 36 (2) ◽  
pp. 149-154 ◽  
Author(s):  
Jiří Vojar ◽  
Petr Chajma ◽  
Oldřich Kopecký ◽  
Vladimír Puš ◽  
Miroslav Šálek
Keyword(s):  
Sex Ratio ◽  
Assortative Mating ◽  
Rana Temporaria ◽  
Bufo Bufo ◽  
The Body ◽  
Operational Sex Ratio ◽  
Wild Populations ◽  
Individual Fitness ◽  
Widespread Phenomenon ◽  
Males And Females

Size-assortative mating (SAM) is a widespread phenomenon related to individual fitness. In our study, we examined: (i) the appearance of SAM, and (ii) the effect of sex ratio on intensity of SAM in wild populations of two explosively breeding anurans, common frogs,Rana temporaria, and common toads,Bufo bufo. Despite a higher male-biased operational sex ratio (OSR) in toads, the body lengths of the paired males and females were significantly correlated only in frogs. Increasing male-male competition, assessed via the OSR, resulted in a stronger correlation also in frogs only. Thus, great variability in the presence and intensity of SAM has been observed within both studied species.

scholarly journals An R package for the integrative evaluation of statistical approaches for cancer incidence projections

2020 ◽  
Author(s):  
Maximilian Knoll ◽  
Jennifer Furkel ◽  
Jürgen Debus ◽  
Amir Abdollahi ◽  
André Karch ◽  
...  
Keyword(s):  
Cancer Incidence ◽  
R Package ◽  
Cancer Registries ◽  
Projection Methods ◽  
Operating Characteristics ◽  
Cancer Registry Data ◽  
Complex Models ◽  
Statistical Approaches ◽  
Term Data

Abstract Background Projection of future cancer incidence is of high importance for epidemiological and biomedical research. Age-Period-Cohort (APC) models are established for such projections, usually based on long-term cancer registry data (>20yrs). In many countries (including Germany), however, nationwide long-term data are not yet available. It is unclear which statistical approach should be recommended for projections using rather short-term data. Methods An R package (incAnalysis) for the comparative analysis of projection methods was developed, supporting in particular Bayesian models fitted by Integrated Nested Laplace Approximations (INLA). It was used to assess operating characteristics (bias, coverage, precision) of various statistical approaches to cancer incidence projection based on artificially shortened long-term data from three cancer registries (SEER-9, NORDCAN, Saarland). Additionally, a novel age-period INLA z-model with multivariate tensor product smoothers is described. Results Coverage was high (mostly >90%) for Bayesian APC models (BAPC), whereas less complex models showed differences in coverage dependent on projection-period. Intercept-only models yielded values below 20% for coverage. Bias increased and precision decreased for longer projection periods for all except intercept-only models. Precision was lowest for BAPC, multivariate smoother and Age-Period GLMs with interaction effect. Conclusion The incAnalysis R package allows for straightforward comparison of (cancer incidence) rate projection approaches. Of the evaluated model classes, more complex models showed an increase in coverage at the cost of precision; bias increased for longer projection intervals, mostly irrespective of the level of complexity.

Hydrogeological responses in tropical mountainous springs

2019 ◽  
Author(s):  
Ricardo Sánchez-Murillo
Keyword(s):  
Costa Rica ◽  
Isotope Composition ◽  
Central Valley ◽  
Distribution Functions ◽  
Geochemical Composition ◽  
Transit Times ◽  
Management Plans ◽  
Best Fit ◽  
Term Data

This study presents a hydrogeochemical analysis of spring responses (2013-2017) in the tropical mountainous region of the Central Valley of Costa Rica. The isotopic distribution of δ18O and δ2H in rainfall resulted in a highly significant meteoric water line: δ2H = 7.93×δ18O + 10.37 (r2=0.97). Rainfall isotope composition exhibited a strong dependent seasonality. The isotopic variation (δ18O) of two springs within the Barva aquifer was simulated using the FlowPC program to determine mean transit times (MTTs). Exponential-piston and dispersion distribution functions provided the best-fit to the observed isotopic composition at Flores and Sacramento springs, respectively. MTTs corresponded to 1.23±0.03 (Sacramento) and 1.42±0.04 (Flores) years. The greater MTT was represented by a homogeneous geochemical composition at Flores, whereas the smaller MTT at Sacramento is reflected in a more variable geochemical response. The results may be used to enhance modelling efforts in central Costa Rica, whereby scarcity of long-term data limits water resources management plans.

Morphometric studies of artemia males from different populations of the Altai region

2020 ◽  
pp. 28-38
Author(s):  
L. Vesnina ◽  
G. Lukerina ◽  
T. Ronzhina ◽  
A. Savos’kin ◽  
D. Surkov
Keyword(s):  
Sexual Dimorphism ◽  
Hydrogen Index ◽  
Morphometric Parameters ◽  
Altai Region ◽  
Sexual Structure ◽  
Different Populations ◽  
Artemia Population ◽  
Term Data ◽  
Brine Salinity

The long-term data from morphometric studies of Artemia males from bisexual and parthenogenetic populations from hyperhaline reservoirs of the Altai region (Bolshoe Yarovoe Lake, Maloe Shklo Lake, and the Tanatar Lakes system) is analyzed in this paper. The description of signs of sexual dimorphism and sexual structure in different populations is given. The influence of brine salinity and hydrogen index on morphometric parameters of males was analyzed. There are differences in the sexual structure of the Artemia population: in the lakes Maloe Shklo and the thanatar system, the populations are bisexual (the share of males is 28.5 — 75.0 %), in the lake Bolshoe yarovoe — parthenogenetic (the share of males on average does not exceed 3 %). At the same time, sexual dimorphism is typical for both types of populations: females are larger than males, males have a larger head (the distance between the eyes is greater by 15.5 %, the diameter of the eye is 26.1 %, the length of the antenna is 22.3 %) and a larger number of bristles (36.1 %). The greatest variability is observed in the parameters of the Furka structure associated with the salinity of water by feedback and the pH — line indicator. Significant differences between the samples of males were revealed. The largest number of significant differences in morphometric indicators was found between samples of males from bisexual populations (lake thanatar and lake Maloe Shklo), the smallest — between males from the parthenogenetic population of lake Bolshoe yarovoe and males from lake Maloe Shklo.

Sign in / Sign up

Export Citation Format

Share Document