Spending One Last Day On Earth: Reproductive Behaviour Of Drosophila Melanogaster Changes Under Selection For Fast Life History

Organisms possess a finite amount of energy which they invest into their schedule of development, reproduction, and survival defining their life history. Because energy is limited trade-offs often arise among life history traits (e.g., body size or maturation time) covarying with the speed of life history schedule. My thesis investigates a complex of Drosophila melanogaster populations that have undergone selection for a fast life history by selecting for an early age at reproduction for approximately 1500 generations. Fast lines develop more quickly, are smaller and females and males are gamete limited in comparison to Control lines; however, most experiments with the Fast populations to date have removed them from the extreme confines of their selection treatment and employed unrelated tester stocks, leaving open questions about the nature of adaptation. For example, these conditions of selection have driven extreme physiological trade-offs, but the impact upon reproductive behaviour received little attention. In Chapter 2, I address this gap by first asking the simple behavioural question: How promiscuous are adult male and female Fast flies? Through an observational approach utilizing a platform constructed to monitor behaviour called an Ethoscope and an onboard object detection model to automate data collection, I describe mating rate and frequency over the entire reproductive window of Fast lines and the early life of Control lines. I observed, Fast lines copulating at a reduced rate compared to Controls, but the underlying mechanisms driving this reduction could not be answered by frequency data alone. In Chapter 3, I investigate the mechanisms behind the reduced copulation rate observed in Fast lines. Under the confines of selection and by employing related tester stocks, I assessed, female fitness and male mating success during controlled mating opportunities and more naturally over a 24 hour period. I demonstrate that male competitive ability has remained at a stable optimum and thus, this reduction in copulation frequency to be most likely attributed to a female decision not to remate.

Department dc:contributor.department

Biology

Year dc:date.issued

2026

Author dc:creator

• Kowal, Joshua Allen Anderson

Advisor dc:contributor.supervisor

• Chippindale, Adam

• Behaviour
• Evolution
• Life History
• Reproduction
• Object Detection
• Ethomics

Statement dc:rights

• Attribution-NonCommercial-NoDerivatives 4.0 International

Licence dc:rights.uri

• http://creativecommons.org/licenses/by-nc-nd/4.0/

Language dc:language.iso

eng

Handle dc:identifier.uri

https://hdl.handle.net/1974/36602

OAI identifier oai:identifier

oai:queensu.scholaris.ca:1974/36602