How daisies make deceptive petals that look like female flies

A daisy in South Africa has evolved a fake-fly lure to attract pollinators, according to Cambridge University researchers. Male flies are drawn in by the fakeries, which resemble female flies. The flies then unwittingly cross-polinate the flowers. The study identified three different groups of genes which had been used to evolve the lure over the past 1.5 to 2.5 million years. The genes had all previously been used for alternative flower functions in the species, Gorteria diffusa.

The exact structure of the lure varied within the species, but all included one to four dots and a raised hair which suggested a female fly. Some daisies lacked the device altogether. The genes used to create the fake-fly were also used to move iron around the plant, produce pigments and tell the plant when to produce flowers. The use of genes already being used by the flower points towards “co-option or recruitment into making this amazing fly mimic”.

The mimicking has been highly successful for the species, which competes against a great number of flowers for pollinators. The annual bursts of flower growth in the Namaqualand desert results in strong competiiton for pollinators. Scientists are still uncertain how genes are copied gradually as plants evolve increasingly complex structures, and the researchers on this study believe that their findings help to unravel this mystery.



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