In the Population Ecology Experiment, fruit flies were used to investigate the factors that enhanced and limited population growth in these species alone as well as in the presence of other species. In this experiment, the effects of high and low population densities in the same size habitat were compared. The habitat was a glass vial containing approximately equal amounts of food and moisture and kept at the same temperature as the other vials that were involved in this project.
[...] In both high and low density, they produced far more offspring than did Virilis in each case. This higher efficiency of breeding also carried over to the competition experiment, where Molanogaster beat out Virilis to be the dominant species. Thus, our initial hypothesis that Virilis would be superior due to their size was not supported by the data, with a higher capacity for breeding being the more important factor in dominance amongst species competition. Within the high and low density experiments, the flies with higher density always yielded a higher amount of flies. [...]
[...] The two populations both started at eight individuals, and after three generations, none of the groups had more than one living D. Virilis, while all but one had a much larger number of D. Melanogaster than in the beginning. The one group that had only three surviving D. Melanogaster flies did not have a single surviving D. Virilis, keeping to the general trend. Data: D. Low Density High Density melanogaster start Finish start Finish Adults larvae Adults larvae pupa pupa Group start Finish start Finish Adults larvae Adults larvae pupa pupa Group Group start Finish start Finish Figure Figure Figure Figure Figure Discussion: In the end, the tiny D. [...]
[...] virilis flies into the vial. We put equal numbers of male and females( 4 of each for each species). After one week we discarded all the adults. After three weeks, we separated and counted the number of second generation adults of each species. Results: For the population density experiment the data taken was generally uniform, with a few exceptions. In the low density experiment for D. Melanogaster all but two of the groups showed a much higher number of pupa to larvae, Figure averaging 40.5 pupa to 21.83 larvae. [...]
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