THIS CONTENT IS BROUGHT TO YOU BY NTNU Norwegian University of Science and Technology - read more
Darwin’s giant plant shows how species adapt
A new study reveals how a remarkable group of plants on the Galápagos developed its diverse leaf shapes. The research offers unique insight into evolution at the genetic level.
The Galápagos Islands hold an iconic status in the history of evolution.
When Charles Darwin went ashore there in 1835 during his voyage on the HMS Beagle, he collected birds that he later brought back to England.
Darwin believed he had gathered sparrows, woodpeckers, finches, and a single tit. But he soon learned that all of them were, in fact, closely related finches.
The birds looked different because they had different beak shapes, adapted to different diets.
These finches became a key argument for Darwin’s theory of evolution – that species are shaped by their surroundings through natural selection.
The islands hold more secrets
“More than 150 years after Darwin’s work on the Galápagos transformed our understanding of life on Earth, these islands continue to reveal new secrets,” says Professor Michael D. Martin at the NTNU University Museum.
He is part of a large international team of researchers who have studied evolution in the plant group Scalesia, also known as the Galápagos giant daisies.
The research was recently published in Nature Communications.
Unusually rapid evolution
“Just like Darwin’s famous finches, these plants evolved rapidly after arriving on the Galápagos from mainland South America,” explains Vanessa Bieker.
She is a researcher at the Royal Botanic Gardens, Kew.
The Scalesia genus is evolutionarily young. All species living today emerged within the last one million years.
Even so, they have managed to adapt to the wide range of environments found across the islands – from dense, humid highland forests to dry, open lowlands.
The leaves are especially striking
“The appearance of different species varies dramatically, from low shrubs to tall trees. Most striking are the leaves, which range from large and entire to small and deeply lobed,” says Martin.
Lobed leaves are thought to help plants survive in hot, dry environments by reducing water loss and dissipating heat, he explains.
Until now, however, researchers have not understood how this important adaptation evolved at the genetic level in these plants.
Multiple evolutionary paths to the same leaf shape
By analysing the complete DNA of all known Scalesia species, the researchers discovered that lobed leaves evolved several times – each time in different parts of the Scalesia family tree.
“Even more surprising was that each time this trait evolved, it did so through different genes – even though all of them belong to the same biological system controlling leaf development,” says Bieker.
A clear example of parallel evolution
She explains that this finding provides a clear example of parallel evolution: nature arriving at the same solution multiple times, but through different genetic pathways.
"Instead of being controlled by a single ‘master gene’, evolution appears to draw on an entire network of interacting genes, tweaking different components to produce similar outcomes,” she says.
This gives researchers important insight into how complex traits can arise again and again in nature.
Evolution is still ongoing
In addition to uncovering how these plants evolved, the researchers found that evolution is still ongoing.
Populations within the same species show large genetic differences and have been isolated from one another for long periods.
"This means new species may be in the process of forming. Many Scalesia populations may represent distinct evolutionary lineages that have not yet been formally described,” says Martin.
The researchers therefore believe that each isolated population should be treated as its own conservation unit.
Could change how nature in the Galápagos is protected
This is a change that could affect how the unique nature of the Galápagos is protected in the future.
The study also offers a rare, detailed look at the process by which one species rapidly diversifies into many different forms.
“Our findings highlight the flexibility and creativity of evolution,” says Bieker.
She adds that Darwin also collected many plants on the Galápagos.
78 of these were later used to describe species that were entirely new to science, including four species of Scalesia.
Reference:
Bieker et al. The genomic basis of adaptive leaf variation in the Galápagos giant daisies, Nature Communications, 2026. DOI: 10.1038/s41467-026-71865-3
More content from NTNU:
-
Why preschool teachers show kids emojis
-
Study: Many teens sext on social media
-
Are boys more motivated and girls more compassionate?
-
Why seafarers have little confidence in autonomous ships
-
These house sparrows can help us save other endangered animals
-
Experienced therapists can give psychology students an extra boost
