Researchers have discovered that distantly related butterflies and moths have used the same two genes, ivory and optix, for more than 120 million years to create similar warning colors on their wings. This finding suggests evolution can follow predictable genetic pathways rather than being entirely random. The study focused on species from South American rainforests.
An international team led by the University of York and the Wellcome Sanger Institute examined seven distantly related butterfly species and a day-flying moth. Despite their evolutionary separation, these insects share nearly identical wing patterns that warn predators of their toxicity. The researchers identified that evolution repeatedly activated the genes ivory and optix to produce these colors, without changing the genes themselves but modifying regulatory switches that control their expression. In the moth, an inversion of DNA mirrored a mechanism in one butterfly species. The findings appear in the journal PLOS Biology. Professor Kanchon Dasmahapatra from the University of York's Department of Biology said: “Evolution can be surprisingly predictable, and that butterflies and moths have been using the exact same genetic tricks repeatedly to achieve similar color patterns since the age of the dinosaurs.” Professor Joana Meier from the Wellcome Sanger Institute explained the advantage: “These distantly related butterflies and the moth are all toxic and distasteful to birds. If birds have already learned that a specific color pattern means 'do not eat, we are toxic,' it is beneficial for other species to display the same warning colors.” This conserved genetic basis spans over 120 million years, hinting that evolution reuses established pathways. Such patterns could aid predictions of how species adapt to environmental changes, according to the researchers.
