A groundbreaking study examining various South American butterfly lineages and diurnal moths reveals that convergent evolution—where unrelated species develop similar traits—follows a consistent genetic pattern. This discovery has significant implications for understanding how species may adapt to climate change.
Ben Chehida and others. A flight study of Itomini, Isomini, and Heliconius butterflies, along with the Ketonga moth. Image credit: Ben Chehida et al., doi: 10.1371/journal.pbio.3003742.
“Convergent or parallel evolution serves as a natural experiment where unrelated species independently evolve similar traits in response to equivalent selective pressures,” states Kanchon Dasmahapatra, a professor at the University of York.
“This indicates how reproducible—and thus predictable—evolution can be.”
“Highly divergent lineages often display significant trait convergence, such as repeated colonization of habitats like land, water, and air, or the evolution of resistance against threats like pesticides, drought, and heat stress.”
According to the researchers, “Convergence in traits across different species can stem from genetic changes occurring in different genes or in the same gene (gene reuse).”
“Gene reuse is expected to be more prevalent among closely related lineages or when developmental pathways towards optimal fitness are limited.”
“Convergence may happen when the same allele is reused (allele sharing), either through independent mutations in one gene or through ancestral variation and introgression between species.”
In this study, the authors investigated various species of distantly related South American rainforest butterflies and moths that share similar wing color patterns for predator deterrence, a phenomenon known as mimicry.
The study aims to identify the genes responsible for these similar mimic color patterns among seven distantly related species.
Remarkably, researchers found that distinct butterfly and moth species reuse the same two genes—ivory and optics—which evolve into similar color patterns, despite being very distant relatives.
Genetic alterations in several butterfly species did not occur in the genes themselves but rather in similar “switches” that control gene expression.
Interestingly, one moth species utilizes an inversion mechanism where substantial DNA sequences flip directions, mirroring a genetic strategy used by a butterfly.
“Convergent evolution, where numerous unrelated species independently develop the same trait, is a widespread phenomenon across the tree of life,” says Professor Dasmahapatra.
“However, there is limited opportunity to explore the genetic foundation of this phenomenon.”
“By studying seven butterfly lineages along with diurnal moths, we demonstrate that evolution is surprisingly predictable and that both butterflies and moths have repeatedly employed the same genetic tricks to develop similar color patterns since the time of dinosaurs.”
The findings from this study reveal that evolution may not always be random and could be more predictable than previously believed.
Professor Joanna Meyer from the Wellcome Sanger Institute remarked: “All these distantly related butterflies and moths are toxic and unpalatable to birds that attempt to consume them.”
“Their similarities are advantageous; if birds recognize a specific color pattern as indicating ‘don’t eat us, we are poisonous’, it benefits other species to exhibit the same warning colors.”
“Our research illustrates that these warning colors are remarkably optimal. With a highly conserved genetic basis over 120 million years, evolving these similar color patterns could be quite straightforward.”
The results are published in the journal PLoS Biology.
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Y. Ben Chehida et al. 2026. Convergent mimic coloration in lepidopterans over 120 million years of evolution is underpinned by genetic parallelism. PLoS Biol 24 (4): e3003742; doi: 10.1371/journal.pbio.3003742
Source: www.sci.news
