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Circadian Entrainment of Drosophila Melanogaster
Published on: June 3, 2020
Heritable circadian period length in a wild bird population
Barbara Helm1, Marcel E Visser
1Max Planck Institute for Ornithology, 82346 Andechs, Germany. helm@orn.mpg.de
Proceedings. Biological Sciences
|June 11, 2010
Summary
Circadian clocks, crucial for timekeeping, are understudied in evolutionary ecology. This study reveals significant genetic variation in great tits' free-running period length, suggesting it’s influenced by sexual selection.
Area of Science:
- Evolutionary Ecology
- Chronobiology
- Animal Behavior
Background:
- Circadian clocks are vital for timekeeping but largely unaddressed in evolutionary ecology.
- The free-running period length (τ) of circadian clocks is key but poorly understood in natural populations.
- Understanding circadian traits in wild vertebrates is crucial for linking behavior, physiology, and fitness.
Purpose of the Study:
- To investigate natural variation in circadian clock traits, specifically free-running period length (τ), in a wild songbird population.
- To determine the heritability and genetic variation of circadian period length in the great tit (Parus major).
- To explore potential links between circadian period length and sexual selection in this species.
Main Methods:
- Recorded locomotor activity of 98 hand-raised, wild-derived great tits under constant dim light conditions.
- Analyzed variation in free-running period length (τ) among individuals.
- Assessed heritability (h²) and genetic variation of τ, and compared periods between within-pair and extra-pair offspring.
Main Results:
- The free-running period length (τ) of great tits was unexpectedly shorter than 24 hours in constant dim light.
- Demonstrated significant genetic variation and high heritability (h² = 0.86 ± 0.24) for period length in this wild vertebrate.
- Offspring from extra-pair matings exhibited significantly shorter free-running periods than their half-siblings from within-pair matings.
Conclusions:
- Circadian clock period length is a heritable and potentially micro-evolutionarily mutable trait in wild populations.
- Shortened circadian period length may be influenced by sexual selection, suggesting a role for internal clocks in mate choice and reproductive success.
- This study highlights the importance of integrating chronobiology into evolutionary ecology to understand fitness-relevant behavioral variation.
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