Altering an extended phenotype reduces intraspecific male aggression and can maintain diversity in cichlid fish
| Autor: | Domino A. Joyce, Isabel S. Magalhaes, Guy E. Croft |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2013 |
| Předmět: |
0106 biological sciences
Population Zoology lcsh:Medicine Negative frequency-dependent intrasexual selection 010603 evolutionary biology 01 natural sciences General Biochemistry Genetics and Molecular Biology Intraspecific competition 03 medical and health sciences Cichlid Male aggression medicine Extended phenotype 14. Life underwater Haplochromine cichlid Mating education 030304 developmental biology 0303 health sciences education.field_of_study biology Animal Behavior Aggression General Neuroscience lcsh:R General Medicine Bower Microcephalus biology.organism_classification Evolutionary Studies Female preference Natural population growth Sexual selection Lake Malawi medicine.symptom General Agricultural and Biological Sciences |
| Zdroj: | PeerJ PeerJ, Vol 1, p e209 (2013) |
| ISSN: | 2167-8359 |
| Popis: | Reduced male aggression towards different phenotypes generating negative frequency-dependent intrasexual selection has been suggested as a mechanism to facilitate the invasion and maintenance of novel phenotypes in a population. To date, the best empirical evidence for the phenomenon has been provided by laboratory studies on cichlid fish with different colour polymorphisms. Here we experimentally tested the hypothesis in a natural population of Lake Malawi cichlid fish, in which males build sand-castles (bowers) to attract females during seasonal leks. We predicted that if bower shape plays an important role in male aggressive interactions, aggression among conspecific males should decrease when their bower shape is altered. Accordingly, we allocated randomly chosen bowers in a Nyassachromis cf. microcephalus lek into three treatments: control, manipulated to a different shape, and simulated manipulation. We then measured male behaviours and bower shape before and after these treatments. We found that once bower shape was altered, males were involved in significantly fewer aggressive interactions with conspecific males than before manipulation. Mating success was not affected. Our results support the idea that an extended phenotype, such as bower shape, can be important in maintaining polymorphic populations. Specifically, reduced male conspecific aggression towards males with different extended phenotypes (here, bower shapes) may cause negative frequency-dependent selection, allowing the invasion and establishment of a new phenotype (bower builder). This could help our understanding of mechanisms of diversification within populations, and in particular, the overall diversification of bower shapes within Lake Malawi cichlids. |
| Databáze: | OpenAIRE |
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