A landmark study of several butterfly lineages and a day-flying moth in South America shows that convergent evolution — when unrelated species arrive at the same solution — isn’t just a coincidence; it follows a surprisingly consistent genetic script, and this discovery could help predict how species adapt to climate change.
Ben Chehida et al. studied convergent evolution in multiple mimetic Neotropical lepidopteran lineages that diverged between 1 and 120 million years ago, including seven species of Ithomiini and Heliconius butterflies and a day-flying Chetone moth. Image credit: Ben Chehida et al., doi: 10.1371/journal.pbio.3003742.
“Convergent or parallel evolution is a natural experiment where unrelated species independently evolve similar traits in response to similar selective pressures,” said University of York’s Professor Kanchon Dasmahapatra and colleagues.
“It informs us about the extent to which evolution is repeatable and thus predictable.”
“Highly divergent lineages can show strong trait convergence, for example, associated with the repeated colonization of land, water, or air or the repeated evolution of resistance to challenges like insecticides or drought and heat stress.”
“Trait convergence in different species can be caused by genetic changes at different genes or the same gene (gene reuse),” they added.
“Gene reuse is predicted to be more common among closely related lineages or when developmental pathways towards shared fitness optima are constrained.”
“Where genes are reused, convergence may result from independent mutations at the same gene or because the same alleles are reused (allele sharing), either from ancestral standing variation or as a result of introgression between species.”
In new research, the authors studied several distantly related South American rainforest butterfly and moth species that sport similar wing color patterns that warn away predators, a phenomenon known as mimicry.
The aimed to discover the genes controlling these similar mimicry color patterns among seven distantly related species.
They found that despite being very distantly related to each other, the various butterfly and moth species reused the same two genes — ivory and optix — to evolve near identical color patterns.
The genetic changes in the different butterfly species did not happen in the genes themselves, but in similar ‘switches’ that turn the genes on or off.
The moth species surprisingly used an inversion mechanism — a large chunk of DNA flipped backwards — a near identical genetic trick used by one of the butterflies.
“Convergent evolution, where many unrelated species independently evolve the same trait, is common across the tree of life,” Professor Dasmahapatra said.
“But we rarely have the opportunity to investigate the genetic basis of this phenomenon.”
“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 color patterns since the age of the dinosaurs.”
The findings show that evolution isn’t always a roll-of-the-dice, but can be more predictable than previously thought.
“These distantly related butterflies and the moth are all toxic and distasteful to birds trying to eat them,” said Wellcome Sanger Institute’s Professor Joana Meier.
“They look very much alike because 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.”
“Here, we show that these warning colors are particularly ideal as it seems quite easy to evolve these same color patterns due to the highly conserved genetic basis over 120 million years.”
The results were published online in the journal PLoS Biology.
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Y. Ben Chehida et al. 2026. Genetic parallelism underpins convergent mimicry coloration in Lepidoptera across 120 million years of evolution. PLoS Biol 24 (4): e3003742; doi: 10.1371/journal.pbio.3003742
