Advanced

Does sex-specific attractiveness change because of female-limited selection?

Katsianis, Georgios (2018) BION02 20172
Degree Projects in Biology
Abstract
Using Drosophila melanogaster as a study organism, we tried to find differences in male and female attractiveness due to female-limited X-chromosome evolution (FLX).
In the first part of the experiment, we tested the male attractiveness (measured as female preference) of the FLX-populations and as a control group we used the LHm-population. (LHm comes from a large laboratory-adapted population collected in central California in 1991). In the second part of the experiment, we tested the female attractiveness (male preference). For this experiment, one male (from the LHm population) and two females that both derive from different populations were used, for example, one from the target genotype and one from the competitor genotype (LHm) and... (More)
Using Drosophila melanogaster as a study organism, we tried to find differences in male and female attractiveness due to female-limited X-chromosome evolution (FLX).
In the first part of the experiment, we tested the male attractiveness (measured as female preference) of the FLX-populations and as a control group we used the LHm-population. (LHm comes from a large laboratory-adapted population collected in central California in 1991). In the second part of the experiment, we tested the female attractiveness (male preference). For this experiment, one male (from the LHm population) and two females that both derive from different populations were used, for example, one from the target genotype and one from the competitor genotype (LHm) and we checked which one the male chose to mate with. Since the two females do not differ in appearance, a way to distinguish them was introduced. This was done by using paint as a marker. As a prerequisite, a pilot study was carried out that showed that the visual marker (paint) that was introduced had no effect on mate choice. The male attractiveness experiment did not show any significance, but a trend that the FLX male flies managed to achieve a mating faster. Furthermore, for the female attractiveness experiment the results were not significant, but there was a trend in the vials with the FLX females, where the flies mated faster regardless of the chosen genotype, which could indicate pheromone based preference for FLX females (Less)
Popular Abstract
X-chromosome and sex attractiveness

Evolutionary biology is trying to understand what forces drive change of organisms in a specific direction. The “force” or selection can be a pressure from nature, such as predation, resource competition, or selection from the opposite sex.
In our study we focused on the selection forces arising from the mate choice. In many species, males and females have different optimal appearances. When you notice a fruit fly in your glass of wine, you probably don't think about whether it's a male or female. But the sexes actually look quite different, and can even be identified by the naked eye. The condition where the two sexes of the same species exhibit different characteristics is known as sexual... (More)
X-chromosome and sex attractiveness

Evolutionary biology is trying to understand what forces drive change of organisms in a specific direction. The “force” or selection can be a pressure from nature, such as predation, resource competition, or selection from the opposite sex.
In our study we focused on the selection forces arising from the mate choice. In many species, males and females have different optimal appearances. When you notice a fruit fly in your glass of wine, you probably don't think about whether it's a male or female. But the sexes actually look quite different, and can even be identified by the naked eye. The condition where the two sexes of the same species exhibit different characteristics is known as sexual dimorphism.
There is a paradox here, in that even if the males and females differ in appearance, resulting in sexual dimorphism, the genome they share is basically the same. How does this happen? Do the sex chromosomes perhaps play a major role in forming sexual dimorphism? This would make sense because in XY sex determination systems, the Y chromosome is only found in males, and the X chromosome spends more time in females.
In the laboratory, we created a group where for many generations we forced the X chromosome to be present only in the female of the species. We expected in this group the selection to be driven in favor of the female.
We conducted behavioral assays that had as a purpose to measure the male and the female attractiveness. We compared the group created with other groups that did not have the set up described above.
Our results were mixed and not exactly in line with our expectations. A reason for that could be that there is already strong selection in mate choice in males and females, so there was little scope for a response to the changed inheritance pattern of the X. Also, potentially trade-offs, such as body size vs sperm competition, may mask effects of a response to selection. Such trade-offs could be investigated in future works.


Master’s Degree Project in Animal Ecology 45XX
Department of Biology, Lund University

Advisor: Jessica Abbott
Department of Biology (Less)
Please use this url to cite or link to this publication:
author
Katsianis, Georgios
supervisor
organization
course
BION02 20172
year
type
H2 - Master's Degree (Two Years)
subject
language
English
id
8960262
date added to LUP
2018-10-15 14:15:57
date last changed
2018-10-15 14:15:57
@misc{8960262,
  abstract     = {Using Drosophila melanogaster as a study organism, we tried to find differences in male and female attractiveness due to female-limited X-chromosome evolution (FLX). 
In the first part of the experiment, we tested the male attractiveness (measured as female preference) of the FLX-populations and as a control group we used the LHm-population. (LHm comes from a large laboratory-adapted population collected in central California in 1991). In the second part of the experiment, we tested the female attractiveness (male preference). For this experiment, one male (from the LHm population) and two females that both derive from different populations were used, for example, one from the target genotype and one from the competitor genotype (LHm) and we checked which one the male chose to mate with. Since the two females do not differ in appearance, a way to distinguish them was introduced. This was done by using paint as a marker. As a prerequisite, a pilot study was carried out that showed that the visual marker (paint) that was introduced had no effect on mate choice. The male attractiveness experiment did not show any significance, but a trend that the FLX male flies managed to achieve a mating faster. Furthermore, for the female attractiveness experiment the results were not significant, but there was a trend in the vials with the FLX females, where the flies mated faster regardless of the chosen genotype, which could indicate pheromone based preference for FLX females},
  author       = {Katsianis, Georgios},
  language     = {eng},
  note         = {Student Paper},
  title        = {Does sex-specific attractiveness change because of female-limited selection?},
  year         = {2018},
}