Ray Murr


Article Summary II


Borash, Daniel J., Gibbs, Allen G., Joshi, Amitabh, and Mueller,

Laurence D. A Genetic Polymorphism Maintained by Natural Selection

in a Temporally Varying Environment. The American Naturalist. Vol.

151 #2. February 1998.


This article is over a study on overpopulation in fruit fly larva. The

scientist took the population from a group of long-standing laboratory-

adapted group of larva. One group is uncrowded and the other is put in an

extremely crowded population. After standardization, the eggs were

collected and raised under the test conditions. After the experiments,

the results showed a trade off in fitness components. For example, larva

that where not crowded grew quicker, but the larva that were crowded were

more likely to survive in high ammonia conditions. Also, as the food

source depleted, the larva, in the crowded condition, was more likely to

survive than the other group. The likeliness for survival was caused by

the reduced feeding rate of the group in the crowded population.