Galápagos daisies evolve same leaf shape via different genes

Scientists have discovered that deeply lobed leaves evolved independently multiple times in the Galápagos giant daisies, a group of plants known as Scalesia, through different genetic pathways each time. The finding, reported on July 30, 2026, provides a clear example of parallel evolution in action.

The research, published in Nature Communications, involved an international team led by Professor Michael D. Martin of the Norwegian University of Science and Technology's University Museum and Vanessa Bieker of the Royal Botanic Gardens, Kew. They analyzed the complete genomes of every known Scalesia species, which emerged within the past one million years after arriving from mainland South America.

This matters because it shows how complex traits can repeatedly arise in separate populations, deepening our understanding of adaptive radiation—the process by which one ancestral species rapidly diversifies into many forms suited to different habitats. The plants vary dramatically, from low shrubs to tall trees, with leaves ranging from large and entire to small and deeply lobed, an adaptation that may help them survive dry, hot conditions by limiting water loss and releasing heat more effectively.

The study found that each time the lobed leaf shape evolved, it did so through different genes, all belonging to the same biological system controlling leaf development. Instead of a single master gene, evolution tweaked different components of a genetic network to produce similar physical outcomes.

Charles Darwin collected plant specimens during his 1835 visit to the Galápagos aboard the HMS Beagle, including four Scalesia species later identified as new to science. His work on finches from the islands became powerful evidence for natural selection, and the new research shows the islands continue to reveal evolutionary biology more than 150 years later.

The genetic evidence also indicates that new Scalesia species may be forming, as populations within the same species show large genetic differences and have been isolated for long periods. The researchers argue that each population should be managed as an individual conservation unit, which could change how the distinctive plants and ecosystems of the Galápagos are protected.