Data from: Testing adaptive hypotheses for an evolutionarily conserved trait through slow-motion videos of pollinators

Traits conserved across evolutionary time often provide compelling
examples of key adaptations for a given taxonomic group. Tetradynamy is
the presence of four long stamens plus two short stamens within a flower
and is conserved across most of the roughly 4000 species in the mustard
family, Brassicaceae. While this differentiation in stamens is
hypothesized to play a role in pollination efficiency, very little is
known about the potential function of the two stamen types. The present
study sheds new light on this mystery using wild radish (Raphanus
raphanistrum), a widespread and well-studied tetradynamous plant. We used
data collected from slow-motion videos of pollinators visiting wild radish
flowers to test three non-mutually exclusive adaptive hypotheses: 1) short
and long stamens are specialized for either feeding or pollinating, 2)
short and long stamens are specialized for different pollinator taxa, and
3) the presence of short and long stamens increases pollinator movement
and thus effectiveness. We find evidence consistent with hypothesis three,
but no evidence for hypotheses one or two. Thus, tetradynamy may be an
adaptation for generalized pollination, enabling effective visits by the
variety of pollinators visiting most species of Brassicaceae.