Integrating evolution into ecological modelling: accommodating phenotypic changes in agent based models.

PMCID: PMC3733718This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Evolutionary change is a characteristic of living organisms and forms one of the ways in which species adapt to changed conditions. However, most ecological models do not incorporate this ubiquitous phenomenon. We have developed a model that takes a 'phenotypic gambit' approach and focuses on changes in the frequency of phenotypes (which differ in timing of breeding and fecundity) within a population, using, as an example, seasonal breeding. Fitness per phenotype calculated as the individual's contribution to population growth on an annual basis coincide with the population dynamics per phenotype. Simplified model variants were explored to examine whether the complexity included in the model is justified. Outputs from the spatially implicit model underestimated the number of individuals across all phenotypes. When no phenotype transitions are included (i.e. offspring always inherit their parent's phenotype) numbers of all individuals are always underestimated. We conclude that by using a phenotypic gambit approach evolutionary dynamics can be incorporated into individual based models, and that all that is required is an understanding of the probability of offspring inheriting the parental phenotype

The Environmental Dependence of Inbreeding Depression in a Wild Bird Population

BACKGROUND: Inbreeding depression occurs when the offspring produced as a result of matings between relatives show reduced fitness, and is generally understood as a consequence of the elevated expression of deleterious recessive alleles. How inbreeding depression varies across environments is of importance for the evolution of inbreeding avoidance behaviour, and for understanding extinction risks in small populations. However, inbreeding-by-environment (IxE) interactions have rarely been investigated in wild populations. METHODOLOGY/PRINCIPAL FINDINGS: We analysed 41 years of breeding events from a wild great tit (Parus major) population and used 11 measures of the environment to categorise environments as relatively good or poor, testing whether these measures influenced inbreeding depression. Although inbreeding always, and environmental quality often, significantly affected reproductive success, there was little evidence for statistically significant I x E interactions at the level of individual analyses. However, point estimates of the effect of the environment on inbreeding depression were sometimes considerable, and we show that variation in the magnitude of the I x E interaction across environments is consistent with the expectation that this interaction is more marked across environmental axes with a closer link to overall fitness, with the environmental dependence of inbreeding depression being elevated under such conditions. Hence, our analyses provide evidence for an environmental dependence of the inbreeding x environment interaction: effectively an I x E x E. CONCLUSIONS/SIGNIFICANCE: Overall, our analyses suggest that I x E interactions may be substantial in wild populations, when measured across relevant environmental contrasts, although their detection for single traits may require very large samples, or high rates of inbreeding

Characterisation of the transcriptome of a wild great tit Parus major population by next generation sequencing

Background: The recent development of next generation sequencing technologies has made it possible to generate very large amounts of sequence data in species with little or no genome information. Combined with the large phenotypic databases available for wild and non-model species, these data will provide an unprecedented opportunity to "genomicise" ecological model organisms and establish the genetic basis of quantitative traits in natural populations

Recent Shift in Climate Relationship Enables Prediction of the Timing of Bird Breeding

Large-scale climate processes influence many aspects of ecology including breeding phenology, reproductive success and survival across a wide range of taxa. Some effects are direct, for example, in temperate-zone birds, ambient temperature is an important cue enabling breeding effort to coincide with maximum food availability, and earlier breeding in response to warmer springs has been documented in many species. In other cases, time-lags of up to several years in ecological responses have been reported, with effects mediated through biotic mechanisms such as growth rates or abundance of food supplies. Here we use 23 years of data for a temperate woodland bird species, the great tit (Parus major), breeding in deciduous woodland in eastern England to demonstrate a time-lagged linear relationship between the on-set of egg laying and the winter index of the North Atlantic Oscillation such that timing can be predicted from the winter index for the previous year. Thus the timing of bird breeding (and, by inference, the timing of spring events in general) can be predicted one year in advance. We also show that the relationship with the winter index appears to arise through an abiotic time-lag with local spring warmth in our study area. Examining this link between local conditions and larger-scale processes in the longer-term showed that, in the past, significant relationships with the immediately preceding winter index were more common than those with the time-lagged index, and especially so from the late 1930s to the early 1970s. However, from the mid 1970s onwards, the time-lagged relationship has become the most significant, suggesting a recent change in climate patterns. The strength of the current time-lagged relationship suggests that it might have relevance for other temperature-dependent ecological relationships

Women and power: a theoretical approach using the example of copreneurial businesses

Despite the gradual recognition of strategic issues related to the integration of women into the economy, female entrepreneurship continues to receive little attention. Family business research attributes this situation to a lack of recognition given to the (decisive) role of women in these organizations. However, there is one type of family governance that formally acknowledges the man/woman combination: the copreneurial company. Copreneurs are couples who run a business together. This theoretical article highlights the role of women in the copreneurial context by distinguishing between formal and informal power- the latter being primarily held by women, but which is no less influential. The distribution of power reduces opposition costs between partners and the social costs of non-compliance, and improves the clarity of the entrepreneurial structure. Moreover, it increases satisfaction and a feeling of equality between the partners. These results can be generalized and shed light on the role of women in other entrepreneurial and social contexts. This article is published as part as part of a collection on the role of women in management and business

Diagnosis and management of Cornelia de Lange syndrome:first international consensus statement

Cornelia de Lange syndrome (CdLS) is an archetypical genetic syndrome that is characterized by intellectual disability, well-defined facial features, upper limb anomalies and atypical growth, among numerous other signs and symptoms. It is caused by variants in any one of seven genes, all of which have a structural or regulatory function in the cohesin complex. Although recent advances in next-generation sequencing have improved molecular diagnostics, marked heterogeneity exists in clinical and molecular diagnostic approaches and care practices worldwide. Here, we outline a series of recommendations that document the consensus of a group of international experts on clinical diagnostic criteria, both for classic CdLS and non-classic CdLS phenotypes, molecular investigations, long-term management and care planning

Evolutionary response to selection on clutch size in a long-term study of the mute swan.

Life-history traits in wild populations are often regarded as being subject to directional selection, and the existence of substantial variation and microevolutionary stasis of these characters is therefore a problem in need of explanation. Avian clutch size is an archetypal life-history trait in this context, and many studies have sought to test explanations for stasis in clutch size. Surprisingly, there are many fewer studies that used long-term data to ask how selection acts on clutch size, particularly in a multivariate framework. In this article, we report selection, inheritance, and evolution of clutch size over 25 years in a colony of mute swans using a multivariate quantitative genetic framework to control for correlations with breeding time. We show that clutch size is influenced by both additive genetic and permanent environmental effects and that selection acts on clutch size in combination with breeding time. Natural selection on clutch size is strongly directional, favoring larger clutches, and we observe an increase in clutch size of 0.35 standard deviations, consistent with the expected response based on selection and inheritance of clutch size. We hypothesize that these changes result from recent relaxation of food constraints and predation risks experienced by this colony