Selective Breeding For Dark Preference in Fruit Flies
For this project we used Drosophila Melanogaster, otherwise known as fruit flies. Drosophila Melanogaster are model organisms in the science world because of their short life spans, quick reproduction rates and their small size. We wanted to test different behaviors in the fruit flies and see if we could selectively breed up a trait we chose. We started off by learning about the fruit flies and what their normal traits are. We were put into groups and then were given the task of choosing a behavior to test. My group, Miguel, Alice, Isaiah, and I decided we wanted to see if we could create a preference for dark environments because typically they prefer light. In order to make that preference happen we used artificial selection to breed up the next generation. Artificial selection is when you produce organisms with a desired trait. We decided to artificially select and breed up the fruit flies with the intent of creating one group of flies that prefer light and another group that prefers dark.
What I Tested
For this project my group and I decided that we wanted to attempt to breed fruit flies with a preference towards dark environments. With this experiment we could possibly have evidence to suggest that in future experiments artificial selection for environmental preferences could succeed. For our procedure we placed 10 fruit flies in the dark side of the experiment system above using CO2, once the flies were awake we allowed them to explore the system for 3 minutes. After the 3 minutes were over we used flynap to anesthetize them and place them in petri dishes to determine how many were in each chamber, light or dark, and how many males and females we had. After running multiple trials we had a total of 43 flies go into the dark chamber and 18 go into the light chamber. Our results allowed us to believe we could possibly have created a preference for dark environments. Although our results show that more flies were in the dark chamber we are unsure if the preference for dark environments was actually created or if our results came from other causes such as, negative geotaxis. Fruit flies typically show negative geotaxis which means they stay towards the top, because our system had the pathway to the other chamber in the middle it is unclear if the flies just stayed at the top and didn't see the pathway to switch chambers.
Reflection
During the course of this project I learned a lot about collaboration. I was in charge of anesthetizing the flies in order to move them around. This job was important because if there was too much anesthetization I could have possibly killed the flies and if there was too little anesthetization the flies could have gone loose. While I was anesthetizing the flies my partners were making sure the system was ready to go and that they were in a position to where they could document the results. My partners were all really helpful and engaged in every step of the experiment and I think that because of their contributions our experiment turned out really well.