Bet-hedging as an evolutionary game: the trade-off between egg size and number.

Summary, in English

Bet-hedging theory addresses how individuals should optimize fitness in varying and unpredictable environments by sacrificing mean fitness to decrease variation in fitness. So far, three main bet-hedging strategies have been described: conservative bet-hedging (play it safe), diversified bet-hedging (don't put all eggs in one basket) and adaptive coin flipping (choose a strategy at random from a fixed distribution). Within this context, we analyse the trade-off between many small eggs (or seeds) and few large, given an unpredictable environment. Our model is an extension of previous models and allows for any combination of the bet-hedging strategies mentioned above. In our individual-based model (accounting for both ecological and evolutionary forces), the optimal bet-hedging strategy is a combination of conservative and diversified bet-hedging and adaptive coin flipping, which means a variation in egg size both within clutches and between years. Hence, we show how phenotypic variation within a population, often assumed to be due to non-adaptive variation, instead can be the result of females having this mixed strategy. Our results provide a new perspective on bet-hedging and stress the importance of extreme events in life history evolution.

• Author: Helen Olofsson; Jörgen Ripa; Niclas Jonzén
• Department/s: Evolutionary ecology; Theoretical Population Ecology and Evolution Group
• Publishing year: 2009
• Language: English
• Pages: 2963-2969
• Publication/Series: Royal Society of London. Proceedings B. Biological Sciences
• Volume: 276
• Links: http://dx.doi.org/10.1098/rspb.2009.0500
• Document type: Journal article
• Publisher: Royal Society Publishing
• Topic: Biological Sciences
• Status: Published
• Research group: Theoretical Population Ecology and Evolution Group
• ISBN/ISSN/Other: ISSN: 1471-2954