| latitudinal variation of adh gene frequencies in drosophila melanogaster: a mediterranean instability. | the relationship between allelic frequencies at the adh locus and latitude of origin was studied using selected published data from various parts of the world and original observations. an overall increase of adh-f with increasing latitude was observed but the relationship is not linear. tropical populations are generally similar, having a low frequency of the f allele (average 15 per cent) and a smooth increase with latitude (one per cent for one degree). between 30 and 42 degrees latitude, pop ... | 1989 | 2499559 |