The obligate pollination mutualisms between yucca moths and yuccas are
some of the most obvious cases of coevolution, but the phylogenetic o
rigins and extent of coevolution in these interactions are little unde
rstood. Ecological and phylogenetic information from the yucca moth fa
mily, Prodoxidae, shows that pollination has evolved at least three ti
mes from separate moth behaviors. Passive pollination occurs in Greya
during nectaring by one species and during oviposition by two other sp
ecies. Active pollination among prodoxids has evolved only once, in th
e yucca moths. Several life-history traits necessary for the evolution
of obligate mutualism are common traits within the Prodoxidae, and on
ly active pollination and modified mouthparts appear to have been nove
l traits in the yucca moths. We use moth and host biology in a phyloge
netic framework to establish hypotheses for the evolution of active po
llination and reciprocal specialization in the form of functional nect
arlessness in yuccas.