Flower colour power

Abstract

Turning down flowers on the basis of their colour is unlikely to raise your popularity stakes. Yet, some animal pollinators are adapted for this particular choosiness, which enables them to single out the specfic plant species that they help to propagate by their colour. For example, the red-flowered species of the monkeyflower genus Mimulus is visited exclusively by hummingbirds, whereas its pink sister species is selectively pollinated by bumblebees. Such fastidiousness ensures the reproductive isolation of the two flower species in overlapping habitat ranges. By experimentally switching the colour of the two types of Mimulus, Toby Bradshaw and Doug Schemske have now shown that the adaptation of each plant species to a specific pollinator might be due, in large measure, to a mutation at a single locus that affects flower colour.