A GENETIC-ANALYSIS OF PATH-LENGTH AND PUPATION HEIGHT IN A NATURAL-POPULATION OF DROSOPHILA-MELANOGASTER

Behavior-genetic studies using laboratory strains of Drosphila are often criticized because the results cannot be generalized to natural populations. The genetic component of variation in 2 prepupal behaviors was studied for strains derived from a natural population of D. melanogaster. These strains showed a 2nd-chromosome based contribution to differences in path length (the distance a larva crawls in a yeasted culture dish) with the long path length phenotype dominant over the short. Differences in pupation height (the distance a larva pupates above the surface of the medium) were affected not only by the 2nd chromosomes but also by the 3rd pair of chromosomes. The 2nd pair influenced the differences in pupation height 3-fold more than the 3rd. Intermediate pupation heights were found in the reciprocal crosses. While path lenghts could be replicated in their absolute scores over different days, pupation heights could only be replicated in their relative scores.