Genetic Variation in Piciform Birds: Monophyly and Generic and Familial Relationships

Abstract

Inter and intrafamilial relationships within the New World Piciformes were examined through an electrophoretic analysis of 20 protein-coding loci (19 of which varied between taxa). One individual from each of 26 species representing 25 genera and 5 families was analyzed; Monotus momota (Coraciiformes, Momotidae) was used as an outgroup. Although levels of genetic differentiation were high (the mean Nei's unbiased distance was 1.07), the data proved useful for phylogenetic inference. The jackknife technique was used to estimate the robustness of phylogenetic hypotheses. At the interfamilial level, the results suggest the following groupings: [[[(Bucconidae) (Galbulidae)]{(Picidae)[(Capitonidae) (Ramphastidae)]}]]. These results were consistent with hypotheses of familial relationships proposed by two recent cladistic analyses of morphological character complexes (Simpson and Cracraft 1981, Swierczewski and Raikow 1981). Our data challenge the currently accepted monophyly of the Piciformes, however, in much the same way as do DNA-DNA hybridization data. Agreement among independently derived hypotheses of interfamilial relationships suggests confidence in our knowledge of evolutionary patterns among piciform taxa. Hypotheses of intrafamilial relationships, some of which agreed with morphological patterns obtained in other studies, were presented. This study shows that starch-gel electrophoresis may be useful at higher taxonomic levels.