Evolutionary Ecology
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How social environments affect the selection on animal behavioural types

Funded by the Alexander von Humboldt Foundation and the German Science Foundation, Postdoc Petri T. Niemelä, Advisor: N.J. Dingemanse

The social environment, i.e. interactions between conspecifics, represents one of the most dynamic environmental forces that individuals face, because the individual’s own behaviour as well as conspecifics’ behaviours jointly defines the frequency and intensity of the interactions. Overall fitness of an individual is expected to depend not only on its own behavioural type, but also on the interaction between its own behavioural type and the composition of behavioural types in the population (i.e. its social environment). Differences between behavioural types in time budget conflicts (i.e. activity in one context is adaptive while in other context it is maladaptive) are suggested as one of the main mechanisms mitigating fitness differences between behavioural types in nature and may depend on the social environment. However, despite its role in competition, co-operation and mating, the ecological and evolutionary implications of the social environment have largely been neglected in animal personality studies. In this project, I study 1) whether behavioural plasticity is a function of behavioural type and the social environment and if 2) differences in life-time reproduction success depend on the interaction between behavioural type and social environment. As a model species, I use native field cricket species, Gryllus campestris.

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Evolution of animal personalities

Funded by the Max Planck Society, PhD Student Maria Moiron, Advisor: N.J Dingemanse

From an adaptive perspective, the existence of animal personalities is still a mystery because a more flexible structure of behavior would provide a selective advantage. My project aims to understand why individuals within single populations often differ consistently in their behavioral tendencies across time and contexts. For that purpose, I will investigate the role of feedback loops in explaining how different personality types can stably coexist and persist.

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Integrating pre-and post-mating episodes of sexual selection in the study of sexual trait evolution.

Funded by Biona – Junior scientist award of the Faculty of Biology (LMU) to Cristina Tuni

Reproductive success in males is determined by both, their ability to gain mating partners by displaying attractive sexual traits or fighting competitors (pre-mating sexual selection) and to fertilize female’s eggs by winning competitive interactions against sperm of rival males (post-mating sexual selection). Males that experience higher mating success do not necessarily achieve higher fertilization success due to trade-offs in life-history resource allocation, where energy allocated to mate acquisition will limit any further post-mating investment. Negative correlation between pre- and post-mating traits may indicate that the two forms of selection counteract one another, with profound implications in dictating the rate and direction of evolutionary change. This study investigates phenotypic and genetic correlations between key morphological and behavioural pre- and post-mating sexual traits in the field cricket Gryllus bimaculatus with the aim of revealing evolutionary trade-offs between mating and sperm competition success.

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The evolution of deceptive behaviour in nuptial gift-giving spiders

Funded by GSST - Graduate school of science and technology (Aarhus University, Denmark). PHD Student Paolo Giovanni Ghislandi; Advisors: Cristina Tuni and Prof. Trine Bilde (Aarhus University).

The main goal of this project is to understand how sexual selection drives population divergence in polymorphisms of male sexual traits. Specifically, it will examine how sexual selection shapes the evolution of stable polymorphisms in male alternative reproductive traits in male spiders. In order to increase their mating success males of the species Pisaura mirabilis donate nuptial food gifts to females that consume them during copulation. Gifts vary in their quality consisting of genuine nutritional (prey) gifts or deceptive inedible items eliciting female mate acceptance without conferring any food reward. There is evidence that these traits occur in different frequencies across populations, suggesting differential selective forces among populations. After understanding whether deceptive is fixed or variable and context dependent we will determine whether stable polymorphisms vary consistently among populations, quantifying the frequency of polymorphisms in male traits in multiple spider populations and exploring the ecological factors that lead to male deception.

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