Selection for pupation height in Drosophila melanogaster.

Divergent directional selection for high and low pupation height was practiced in D. melanogaster. A quick response was observed in the two directions of selection. This is the first time selection for low pupation sites was successful. Realized heritabilities were 18% and 13% for the high and low lines. Reciprocal crosses between divergent lines showed little or no dominance for low pupation sites. The need for a strict control of environmental factors when measuring pupation height is emphasized.