Scientists have discovered that evolution isn’t as random as once believed. A new study shows distantly related butterflies and moths have been recycling the same two genes for over 120 million years to produce nearly identical wing color patterns.
Evolution may have a favorite playbook — and it’s been running the same plays for over 120 million years. A new international study published in PLOS Biology has found that distantly related butterfly and moth species in South American rainforests independently evolved near-identical wing color patterns by reusing the exact same two genes, a finding that suggests life on Earth may follow more predictable rules than scientists once assumed.
The research was led by scientists at the University of York and the Wellcome Sanger Institute, with contributions from researchers across several South American countries. The team examined seven butterfly lineages and one day-flying moth species that share strikingly similar warning color patterns — a survival strategy known as mimicry, in which toxic or distasteful species advertise their danger through bold, recognizable markings.
Same Genes, Wildly Different Species
Despite being only distantly related to one another, all of the species studied had evolved their similar color patterns using the same two genes: ivory and optix. Even more striking, the genetic changes weren’t mutations within the genes themselves, but in regulatory “switches” — segments of DNA that control when and where a gene is turned on or off.
In one particularly surprising finding, a moth species used a mechanism called an inversion — essentially a large chunk of DNA flipped backwards — to achieve its color pattern. That trick turned out to be nearly identical to a mechanism used by one of the butterfly species studied, even though the two are separated by tens of millions of years of evolution.
“Investigating seven butterfly lineages and a day-flying moth, we show that evolution can be surprisingly predictable, and that butterflies and moths have been using the exact same genetic tricks repeatedly to achieve similar colour patterns since the age of the dinosaurs,” Kanchon Dasmahapatra, a professor in the University of York’s Department of Biology, said in a news release.
The phenomenon at the heart of the study — convergent evolution — is well-documented across the natural world, from dolphins and fish independently evolving streamlined bodies to birds and bats both developing wings. But scientists rarely get a close look at exactly which genes are responsible. This study offers an unusually detailed window into how that process works at the molecular level.
A Warning System That Pays to Copy
The mimicry rings studied here are part of a broader survival strategy among toxic Lepidoptera — the insect order that includes butterflies and moths. When predators like birds learn to associate a specific color pattern with an unpleasant experience, other species benefit by sporting the same look.
Joana Meier, a Royal Society University Research Fellow and group leader at the Wellcome Sanger Institute, explained that the color patterns function as a shared warning system: if birds have already learned that a specific color pattern signals danger, other species gain protection simply by looking the same. The genetic architecture underlying these patterns appears to be remarkably stable — conserved across more than 120 million years of evolution — which may explain why so many species have been able to independently arrive at the same solution.
Why It Matters
For students studying biology, ecology, or genetics, this research offers a compelling case study in how evolution operates not as pure chance, but as a process constrained and guided by the underlying structure of genomes. The relative ease with which these species can access the same genetic switches may explain why mimicry rings are so common and so stable across ecosystems.
Beyond butterfly wings, the broader implications are significant. If evolution repeatedly gravitates toward the same genetic solutions under similar selective pressures, that predictability could help scientists model how species might respond to new environmental challenges — including those posed by climate change. Understanding the genetic “routes” that are available to a species could inform conservation efforts and help researchers anticipate how wild populations adapt over time.
The study also underscores the value of international scientific collaboration. By bringing together researchers from across South America alongside institutions in the UK, the team was able to study a diverse range of species in their native ecological context — something that would be difficult to accomplish from a single lab or country.
Source: University of York