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.