Data from: Loss of colour pigmentation is maintained at high frequency in a monkey flower population

Colour polymorphisms have long been of evolutionary interest for their diverse roles including mate choice, predator avoidance, and pollinator attraction. While colour variation is often under strong selection, some taxa demonstrate unexpectedly high frequencies of presumed deleterious colour forms. Here we show a genetic variant underlying complete loss of anthocyanin pigmentation has risen to an unexpectedly high frequency of >0.2 in a natural population of the plant Mimulus guttatus. Decreased expression of MYB5 transcription factor is associated with unpigmented morphs. While the allele was only found in heterozygote adults in the wild, suggesting negative selection, experiments were unable to demonstrate a fitness cost for unpigmented plants, suggesting a cryptic selection pressure in the wild. However, life history differences among morphs suggests unpigmented individuals benefit from later flowering and clonal growth. Overall, our study highlights the complex
interplay of factors maintaining variation in nature, even for genes of major effect.