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Séminaire présenté par Dr Carsten SCHRADIN, University of Zurich

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Adaptive Responses to an Unpredictable Environment : Behavior, Physiology and Evolution

Par : Dr Carsten SCHRADIN, Institute of Evolutionary Biology and Environmental Studies, University of Zurich
Date : vendredi 10 décembre 2010 à 11h
Lieu : IPHC, Salle de réunion du DEPE, bât.60

Résumé :
Behavioral flexibility to optimize individual fitness occurs in many species and is regulated by evolved physiological mechanisms. If flexibility in social behavior exists in both sexes, this can lead to changes in the social organization of a population, a phenomenon called social flexibility. Social flexibility can be of advantage in unpredictably changing environments. For example the African striped mouse (Rhabdomys pumilio) can either live solitarily or form extended family groups with communal breeding. The social organization of a population depends on environmental conditions, especially population density and intensity of reproductive competition, which itself is a product of differences in climate and associated changes in food availability. Evolved endocrine mechanisms underlie social flexibility in the striped mouse, which enables individuals to maximize their reproductive success under changing environmental conditions. Social flexibility thus is an adaptive response to an unpredictable environment.

The term adaptation is used by both physiologists and evolutionary biologists to describe how animals adjust to their environment. Short-term environmental changes alter physiological responses and longer term changes result in evolutionary adaptation. In general, adaptation has a direct impact on reproductive success, and physiological adaptation is a product of evolutionary adaptation. I propose to study physiological responses to changing environmental conditions as an evolved trait with measurable fitness consequences. In the future I will study physiological processes that are important for survival and reproduction in an arid environment with variable food and water availability : metabolism (corticosterone), reproduction (testosterone and estrogen receptor α), and osmoregulation (arginine vasopressin and its receptor AVPR1a). The African striped mouse lives in an arid environment with annual droughts, which can differ drastically between years, resulting in differences in water and food availability. Droughts are a major factor of mortality, influencing population density and social organization. The striped mouse is an annual species, producing a new generation each year, providing a unique opportunity to study behavioral, physiological and evolutionary responses to a changing environment. In the future, I will analyze physiological adaptation to environmental changes, fitness consequences of individual differences in physiological adaptation, as well as evolutionary adaptation, i.e. genetic change over time within the study population. The main goal of my research is to understand how evolved physiological mechanisms allow animals to behave adaptively in their changing natural environment.

Contact :
Institute of Evolutionary Biology and Environmental Studies
University of Zurich
Winterthurerstrasse 190
8057 Zürich
Phone : 0041 44-635 5486