Effects of Age and Inbreeding on Fitness in Song Sparrows
Author Information
Author(s): Lukas F. Keller, J. M. Reid, P. Arcese
Primary Institution: University of Zurich
Hypothesis
Does inbreeding depression increase with age in song sparrows?
Conclusion
The study found that reproductive success and survival decline with age in song sparrows, indicating senescence, and that inbreeding depression affects fitness components.
Supporting Evidence
- Annual reproductive success declined in old age in both sexes.
- Survival declined with increasing inbreeding coefficient in males.
- A significant age×inbreeding interaction was observed for male reproductive success.
Takeaway
As song sparrows get older, they have fewer babies and are less likely to survive, especially if they are inbred.
Methodology
The study used pedigree and life-history data from a natural population of song sparrows to analyze the effects of age and inbreeding on reproductive success and survival.
Potential Biases
Potential biases in estimates of inbreeding depression due to extra-pair fertilizations.
Limitations
The study's statistical power to detect interactions may have been low due to small sample sizes in older age groups.
Participant Demographics
The average age of female song sparrows was 2.0 years and males was 2.3 years, with a range of 1 to 10 years.
Statistical Information
P-Value
p=0.016 for females, p=0.023 for males
Statistical Significance
p<0.05
Digital Object Identifier (DOI)
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