One of the more fascinating Darwinian puzzles in sexual selection is that of copulatory wounding. For those taxa displaying this behavior, and that does not engage in traumatic insemination, the function of wound infliction during copulation remains unknown. In this study, the intention was to evaluate the purpose of copulatory wounding in Drosophila melanogaster and the consequences it might have for male and female fecundity. The present study measured the size and number of wounds that males from different stocks of Darwinian fitness imposed on females, as well as the copulation duration and the resulting fecundity. The number of wounds and the total wound size showed no apparent correlation to fecundity, but a significant difference in variation of the number of wounds inflicted on females was observed between males from two different lines of fitness. Wounded females were also considerably more common than non-wounded females, as were wounds that were paired compared to non-paired copulatory wounds. The results suggests that wounding might be an adaptive male trait and a copulatory courtship interpretable to females, implying a possible case of cryptic female choice. Since most wounds were paired, this implies that a bilaterally symmetrical organ is causing these wounds. Also, wounding was not as important for fecundity as previously thought. / Ett av de mer fascinerande Darwinistiska pusslen inom sexuell selektion är skadande under kopulationen. För de taxa som uppvisar detta beteende, och inte engagerar sig i traumatisk insemination, så är funktionen av kopulationsskador okänd. I denna studie så var avsikten att utvärdera syftet av kopulationsskador hos Drosophila melanogaster och de konsekvenser beteendet kan ha för det resulterande antalet avkomma. Denna studie uppmätte storleken och antalet skador som hanar av olika Darwinistisk fitness vållade honor, samt kopulationstiden och antalet avkomma. Antalet skador och den totala storleken av skador visade ingen signifikant korrelation till antalet avkommor, däremot uppvisades signifikanta variationsskillnader mellan hanar av två olika fitnessnivåer. Skadade honor visade sig också vara betydligt vanligare än icke skadade honor och parade skador var även vanligare än icke parade skador. Resultaten indikerade att kopulationsskador kan vara en adaptiv egenskap hos hanar och en form av uppvaktning som honorna kan tyda, vilket kan antyda ett möjligt fall av ”kryptiskt honligt val”. Eftersom de flesta skador var parade, så antyder detta att ett bilateralt symmetriskt organ orsakar skadorna. Kopulationsskador visade sig heller inte vara så viktiga som man tidigare antagit.
Identifer | oai:union.ndltd.org:UPSALLA1/oai:DiVA.org:kau-84494 |
Date | January 2021 |
Creators | Leandersson, Dennis |
Publisher | Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013) |
Source Sets | DiVA Archive at Upsalla University |
Language | English |
Detected Language | English |
Type | Student thesis, info:eu-repo/semantics/bachelorThesis, text |
Format | application/pdf |
Rights | info:eu-repo/semantics/openAccess |
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