Data from: Evolution of female ornamentation in dance flies: valuable gifts are worth dressing up for

Elaborate female ornaments are rare in nature. One explanation for this is
that female investment in ornamentation may take away crucial resources
from other costly life history traits, such as fecundity, for which there
is likely to be a higher fitness return. However, this trade-off between
ornaments and fecundity may be less severe in species where the males
offer the female an edible nuptial gift during mating. The nutrition
gained from mating may make attracting mates with elaborate ornaments more
cost-effective for the female. We investigated this link in dance flies in
which there is large variation in nuptial gifts, as well as female
ornaments. The dataset includes categorical values of the level female
ornamentation per species, based on inspected museum specimens, as well as
the categorical level of nuptial gift value based on previously published
dance fly literature. The dataset also includes a COI/CAD-based
phylogenetic tree of all the dance fly species included in the study, as
well as the R script for the analyses. Our phylogenetic analysis showed
that nuptial gift value is positively associated with the evolution of
female ornaments. We found that species which lack nuptial gifts have no
ornaments, and high levels of female ornamentation has evolved most
frequently in species with a reliable access to an edible nuptial gift
with each mating. Our results also suggest that female ornaments have most
likely evolved following the evolution of nuptial gifts. We argue that the
added benefits from each mating have helped the females to overcome the
costs associated with the development and maintenance of ornaments.