Resolving the relationships of apid bees (Hymenoptera: Apoidea) through the simultaneous analysis of molecular, morphological, and behavioral characters

Phylogenetic analyses that incorporate the most character information also provide the highest explanatory power; unfortunately, such simultaneous or “total evidence” analyses are by no means standard operating procedure among systematic biologists. Here I demonstrate the value of such an approach through a reanalysis of apid bee phylogeny. Whereas prior studies have relied solely on one class of data or the other, this analysis combines previously-published molecular, morphological, and behavioral characters into a single supermatrix. The final dataset accounts for 160 ingroup and 30 outgroup taxa, and includes data from seven gene sequences (16S, 28S, wingless, EF1-α, polII, Nak, LW rhodopsin), 209 adult and larval morphological characters, and a single behavioral character. Direct optimization maximum parsimony analysis returns a strict consensus tree similar to, but much more resolved than, a previous parsimony tree based on molecules alone. These results also support recent claims that cleptoparasitism evolved no more than four times within the family. By accounting for more evidence, this study supersedes previous analyses and provides the most comprehensive treatment yet of apid phylogenetic relationships.