Environmental niche divergence between genetically distant lineages of an endangered water beetle

Historically, there has been considerable disagreement between researchers about the criteria used to discriminate among species. Decisions based on traditional morphological and genetic data alone can be potentially problematic, especially if the hypotheses are contradictory. Today, taxonomy is integrating new methods from different disciplines that study species’ limits and evolution; this diverse range of evidence aids researchers in the recognition of species. Differences in niche characteristics could become a new and useful criterion in helping to decide the status of conflicting taxonomical entities. Ochthebius glaber (family Hydraenidae) is an endangered water beetle typical from southeast Iberian hypersaline streams that shows three clear discrete genetic units within its distribution range. However, there is no evidence to date that these lineages of O. glaber exhibit any adaptive morphological or ecological divergence. Using a modelling approach directed to generate niche rep...