Animals 2 Base Sequence 2 Cactophilic Drosophila 2 Carboxylic Ester Hydrolases 2 Chromosome Mapping 2 DNA Primers 2 DNA polymorphism 2 Drosophila 2 Drosophila Proteins 2 Drosophila buzzatii 2 Drosophila koepferae 2 Excess of nonsynonymous polymorphism Founder effect 2 Genetics, Population 2 Population expansion 2 Species Specificity 2 Variation (Genetics) 2 article 2 comparative study 2 controlled study 2 esterase 2 gene locus 2 genetic variability 2 heterozygosity 2 intraspecific variation 2 molecular genetics 2 nonhuman 2 nucleotide sequence 2 population genetics 2 protein variant 2