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Updated: Jun 1, 2026
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Observation and Quantification of Mating Behavior in the Pinewood Nematode, Bursaphelenchus xylophilus
Published on: December 25, 2016
Female extrapair mating behavior can evolve via indirect selection on males
Wolfgang Forstmeier1, Katrin Martin, Elisabeth Bolund
1Department Behavioural Ecology and Evolutionary Genetics, The Max Planck Institute for Ornithology, D-82319 Seewiesen, Germany. forstmeier@orn.mpg.de
Summary
Extrapair mating behavior in socially monogamous species has a hereditary component shared between sexes. This suggests female extrapair mating may evolve indirectly through selection on males, even without direct female benefit.
Area of Science:
- Evolutionary biology
- Behavioral genetics
Background:
- Socially monogamous species often exhibit significant extrapair offspring, with unclear benefits for females despite their active solicitation.
- Adaptionist explanations for female extrapair mating remain controversial, while genetic constraint arguments are often overlooked.
Purpose of the Study:
- To investigate the hereditary basis of extrapair mating behavior in socially monogamous species.
- To test the hypothesis that shared genetic variants influence extrapair mating behavior in both sexes.
Main Methods:
- Studied extrapair mating behavior in the socially monogamous zebra finch.
- Analyzed individual differences for hereditary components.
- Assessed genetic correlations between male and female extrapair mating behavior.
Main Results:
- Individual differences in extrapair mating behavior demonstrate a hereditary component in zebra finches.
- A strong genetic correlation exists between male and female extrapair mating behavior, indicating a shared genetic basis.
- This shared genetic basis implies female behavior can be an evolutionary response to selection on males.
Conclusions:
- Female extrapair mating behavior may evolve via indirect selection on males due to shared genetic underpinnings.
- This challenges the assumption that females must derive a direct net benefit from extrapair copulations.
- Female extrapair mating could persist as a correlated response to alleles positively selected in ancestral males.
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