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Experimental evidence that density mediates negative frequency-dependent selection on aggression.

R Julia Kilgour1, Andrew G McAdam1, Gustavo S Betini1

  • 1Department of Integrative Biology, University of Guelph, Guelph, ON, Canada.

The Journal of Animal Ecology
|February 16, 2018
PubMed
Summary
This summary is machine-generated.

Aggression benefits resource access but variation persists. This study found that density and frequency-dependent selection impact aggression, with rare strains surviving better at higher densities, maintaining behavioral diversity.

Keywords:
Drosophila melanogasterHawk-Dove modelsbehavioural phenotypescompetitionresource defence theoryresource limitation

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Area of Science:

  • Evolutionary Biology
  • Behavioral Ecology

Background:

  • Aggression can be advantageous for resource acquisition in competitive settings.
  • Persistent variation in aggressive behaviors suggests that high aggression is not always favored.

Purpose of the Study:

  • To experimentally investigate how population density and phenotypic frequency affect selection on aggression.
  • To understand mechanisms maintaining variation in aggressive behaviors.

Main Methods:

  • Compared survival of two aggressive strains of Drosophila melanogaster.
  • Utilized three population density treatments and five frequency treatments.
  • Assessed survival during limited resource availability.

Main Results:

  • Survival was density-dependent, decreasing as density increased.
  • Negative frequency-dependent selection (rare strains survived better) occurred at medium and high densities, but not low density.
  • No survival difference was observed in single-strain treatments.

Conclusions:

  • The selective advantage of aggression depends on population density and the frequency of aggressive phenotypes.
  • Density and frequency-dependent selection are key mechanisms for maintaining variation in aggressive behaviors in natural populations.