Selection at the alcohol dehydrogenase locus in Drosophila melanogaster imposed by environmental ethanol

Abstract

This paper describes selective differences imposed by environmental ethanol on six genotypes at the alcohol dehydrogenase (Adh) locus in Drosophila melanogaster. Probit analyses were used to relate differences between the percentage survival of adults of different Adh genotypes to ethanol concentration. Regression analyses were used to relate differences between the pre-adult developmental times of different Adh genotypes to ethanol concentration. The directions of differences between some of the genotypes were found to differ in these two components of fitness. The differences in developmental time are linearly related to the differences in the in vitro alcohol dehydrogenase activity expressed by these genotypes. Percentage survival differences amongst adults are not linearly related to these differences in enzymic activity. The development of AdhF AdhF pre-adults is retarded the least on ethanol impregnated media but AdhFAdhS adults are most likely to survive on such media.