Environmental Constraints on Evolution in Soay Sheep
Author Information
Author(s): Alastair Wilson, Loeske Kruuk
Hypothesis
A variable environment could limit the micro-evolution of birth weight in Soay sheep by affecting heritability and selection.
Conclusion
Environmental quality influences both the genetic variance and the strength of selection for birth weight in Soay sheep.
Supporting Evidence
- Birth weight is linked to juvenile mortality, with larger lambs having higher survival rates.
- The study covered nine generations of Soay sheep over 20 years.
- Environmental quality affects the heritability of birth weight.
- The strength of selection for birth weight decreases in better environmental conditions.
Takeaway
The environment affects how much baby sheep can grow and survive, which means they aren't getting bigger even though they could if conditions were better.
Methodology
The researchers used a theoretical model adapted from animal breeding and applied random regression analysis to study the effects of environmental variation on selection and heritability.
Limitations
The study's findings are based on a specific wild population and may not generalize to other species or environments.
Participant Demographics
The study focused on a population of Soay sheep on the Scottish island of Hirta.
Digital Object Identifier (DOI)
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