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The influence of past and present ecology on reproductive strategies and life history trade-offs

English title The influence of past and present ecology on reproductive strategies and life history trade-offs
Applicant Taborsky Barbara
Number 111796
Funding scheme Project funding
Research institution Ethologische Station Hasli Institut für Ökologie und Evolution Universität Bern
Institution of higher education University of Berne - BE
Main discipline Zoology
Start/End 01.08.2006 - 28.02.2010
Approved amount 304'126.00
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All Disciplines (2)


Keywords (6)

life history; development; evolution; parental investment; brood care; theoretical models

Lay Summary (English)

Lay summary
The environmental conditions an individual experiences during early ontogeny may shape phenotypes and their life histories irreversibly for the entire life time. Moreover early-environment effects can be transmitted between generations through maternal influences on propagule phenotype. Although the importance of early environment for life history evolution is increasingly acknowledged by the research fields as diverse as human medicine, gerontology and evolutionary biology, we still do not know much about the possible adaptive value of these effects, and about the precise physiological mechanism induced by the early-environment. It is hence of great importance to investigate the function and the underlying mechanisms and potential constraints when trying to understand the evolution of early-environment effects. In this project, we aim (i) to test for irreversible physiological adaptations in response to early nutrition, (ii) to investigate the adaptiveness of early-environment effects that are transmitted between generations via propagule size and(iii) to explore how the environment triggers maternal effects on propagule size. We will use African mouthbrooding cichlids as model system for life history evolution of iteroparous, long-lived vertebrates.
(In a long-term experiment we shall test for the physiological manifestations of early environmental conditions, namely the effects of nutrition on energy allocation pathways, the efficiency of the digestive system and food conversion, and on organ size and structure. If these manifestations can be shown to be irreversible, observed effects of early conditions on adult life history strategies may already be programmed at a very early stage in life.
In several mammals, birds and fish it has been shown that the conditions a mother was exposed to early in life determines the propagule size she produces. Furthermore, it has been hypothesised that mothers produce an offspring size that is tailored to the future environment of the young. To disentangle these links between maternal and offspring environments and maternal decisions, one first needs to understand the selective forces that influence maternal investment in offspring size. We will hand-raise small and large eggs in a paired design in order to be able to test for the consequences of egg size in absence of confounding factors. The fitness of young hatched from small and large eggs, respectively, will be tested in adverse and favourable conditions with regard to food availability, predation risk and competitor density in the lab, and in poor and rich habitat patches in the field. Second, one needs to understand how the maternal early and current environments and the offspring environment act on mothers' decisions about offspring size. This will be investigated by combining theoretical modelling and a validation of the main assumptions of the models in the field and in lab experiments.
Direct link to Lay Summary Last update: 21.02.2013

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133066 Developmental plasticity of social behaviour: fitness effects, molecular and physiological mechanisms 01.11.2010 Project funding