Let's not Abandon Science for Advocacy: Reply to Berg and Berg.

Abstract

Berg and Berg (2000) conduct an analysis of their unpublished allozyme data for populations of Amblema and report that as sample size increases the opportunity detect rare alleles increases. They argue that to discriminate among within a genus, one must quantify the degree of variation both among populations within each and among putative species and that the accuracy of the estimation of variation increases with sample size. We wholeheartedly agree. Indeed, our study was undertaken provide additional data address questions arising from just such a lack of comparative analysis and small sample size. Berg and Berg point out that sample sizes in our study of the freshwater mussels Megalonaias and Amblema were small and that small sample sizes may lead Type II statistical errors. We completely agree, but recognize that the alternative Type I error has serious consequences as well. Regrettably, small sample sizes are often the norm with that are being considered for federal listing as endangered, threatened, or of special concern, as was the case in our study. Where taxonomic evaluations are made, voucher specimens are absolutely necessary cross-check genetic data and validate specimen identifications (Lydeard & Roe 1998). Among molluscs, traditional morphological and conchological traits, often coupled with small sample sizes, have led a proliferation of named entities (e.g., Lea 1834). Recognition of ecophenotypic plasticity and evaluation of larger population samples and comparative material has led many of these names becoming synonymous. Molecular genetic approaches are often useful for addressing taxonomic ambiguity (Mulvey et al. 1998). Unfortunately, many people, perhaps Berg and Berg among them, view named entities as unassailable, especially in the context of conservation. This position is indefensible and counterproductive.