, Volume 135, Issue 1, pp 7–11

Variation in the peacock’s train shows a genetic component



Female peafowl (Pavo cristatus) show a strong mating preference for males with elaborate trains. This, however, poses something of a paradox because intense directional selection should erode genetic variation in the males’ trains, so that females will no longer benefit by discriminating among males on the basis of these traits. This situation is known as the ‘lek paradox’, and leads to the theoretical expectation of low heritability in the peacock’s train. We used two independent breeding experiments, involving a total of 42 sires and 86 of their male offspring, to estimate the narrow sense heritabilities of male ornaments and other morphometric traits. Contrary to expectation, we found significant levels of heritability in a trait known to be used by females during mate choice (train length), while no significant heritabilities were evident for other, non-fitness related morphological traits (tarsus length, body weight or spur length). This study adds to the building body of evidence that high levels of additive genetic variance can exist in secondary sexual traits under directional selection, but further emphasizes the main problem of what maintains this variation.


Lek paradox Fitness-related traits Narrow sense heritability Additive genetic variation 

Copyright information

© Springer Science+Business Media B.V. 2007

Authors and Affiliations

  • Marion Petrie
    • 1
  • Peter Cotgreave
    • 2
    • 4
  • Thomas W. Pike
    • 3
    • 5
  1. 1.Evolutionary Biology Research Group, School of Clinical Medical SciencesUniversity of NewcastleNewcastle-upon-TyneUK
  2. 2.Department of ZoologyUniversity of OxfordOxfordUK
  3. 3.School of BiologyUniversity of NewcastleNewcastle-upon-TyneUK
  4. 4.Campaign for Science & EngineeringLondonUK
  5. 5.Division of Environmental and Evolutionary Ecology, Graham Kerr BuildingUniversity of GlasgowGlasgowUK

Personalised recommendations