Abstract
The conditional evolutionarily stable strategy (ESS) with status-dependent tactics is the most commonly invoked ESS for alternative reproductive tactics within the sexes. Support for this model has recently been criticized as apparent rather than real. We address key predictions of the status-dependent ESS in three populations of the male dimorphic mite Sancassania berlesei. In S. berlesei'fighter' males are characterized by a thickened pair of legs used for killing rivals; 'scramblers' are benign. Most males in each population could be manipulated to become fighters by decreasing density, fulfilling the prediction that males make a 'decision'. There was evidence of genetic covariance between sire status and offspring morph, but also a strong effect of sire morph on offspring morph ratio. This was consistent with considerable genetic variation for the status-dependent switch point as a breeding experiment found no support for single-locus inheritance. We also found evidence that switch points evolve independently of distributions of status. This study supports the current status-dependent ESS model.
Original language | English |
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Pages (from-to) | 1377–1388 |
Journal | Journal of Evolutionary Biology |
Volume | 17 |
Issue number | 6 |
DOIs | |
Publication status | Published - Nov 2004 |
Keywords
- alternative reproductive strategies
- male polyphenism
- Onthophagus taurus
- phenotypic plasticity
- reaction norm
- ONTHOPHAGUS-ACUMINATUS COLEOPTERA
- ALTERNATIVE REPRODUCTIVE TACTICS
- MALE MORPH DETERMINATION
- DIMORPHIC MALE BEETLES
- MALE HORN DIMORPHISM
- FORFICULA-AURICULARIA
- TAURUS COLEOPTERA
- LENGTH DIMORPHISM
- EUROPEAN EARWIG
- SCARABAEIDAE