Rosa Rubicondior: Creationism In Crisis - After Darwin's Finches It's Darwin's Daisies

Serrated leaves of Scalesia affinis (radiate-headed scalesia)

Photo: Michael Martin, NTNU University Museum

Botany’s answer to Darwin’s finches shows evolution in real time

The Galápagos Islands occupy an iconic place in the history of evolutionary biology. The animals and plants Darwin encountered there during the voyage of HMS Beagle contributed important evidence to the theory he developed after returning to England: that living species are not fixed and immutable but are the products of a long historical process.

Darwin eventually realised that natural selection acting upon inherited variation could produce organisms that appeared designed for their environments, without foresight, planning or divine intervention. Individuals possessing variations that gave them an advantage in their particular circumstances tended to leave more descendants, causing those variations to become more common over successive generations.

Like the uniformitarian geologists—particularly Charles Lyell—Darwin recognised that the world as we see it is not a fixed unchangeable result of a single act of perfect creation, but is the product of natural processes operating over immense periods of time. The processes that shaped the past are still operating today and will continue to shape the future.

The familiar story that Darwin saw the Galápagos finches and immediately conceived his theory is, however, an oversimplification. During the voyage, he believed he had collected birds belonging to several different groups, including finches, grosbeaks, blackbirds, wrens and warblers. Only after the ornithologist John Gould examined the specimens in England did it become apparent that these apparently disparate birds belonged to a distinctive group of closely related species—what we now call Darwin’s finches, although taxonomically they are members of the tanager family.

Darwin then appreciated the evolutionary significance of their shared characteristics and striking differences. Their varied body sizes and beaks could be understood as modifications of a common ancestral form, associated with different diets and ecological niches throughout the archipelago. One ancestral population had diversified into numerous related forms: a process now known as adaptive radiation.

The standard creationist response is to dismiss Darwin’s finches as evidence for evolution because they remain recognisably finch-like. This objection depends upon the childish parody of evolution in which one species should turn suddenly into an entirely different and supposedly unrelated species. Such an event would not demonstrate evolution; it would contradict the branching process of descent with modification. Descendants necessarily remain related to their ancestors and inherit modified versions of ancestral structures.

This misconception lies behind such familiar creationist “Gotchas!” as “Why do we never see evolution happening?” and “Why has evolution stopped?” Evolution has not stopped. What creationists demand to see is not evolution but an instantaneous transformation that evolutionary biology neither predicts nor requires.

Darwin knew nothing of Mendelian genetics or DNA, of course. Modern genomic research has confirmed the common ancestry of his finches while revealing a history more complicated than a simple, neatly branching tree. Rapidly diverging lineages can retain genetic variants inherited from their common ancestor and can occasionally exchange genes through hybridisation.

Now, genomic research into a family of plants—the genus Scalesia, commonly known as the Galápagos giant daisies—has provided a botanical counterpart to Darwin’s finches. In only about one million years, the founding lineage has diversified into 15 recognised species occupying habitats ranging from dense, humid highland forests to hot, dry and exposed lowlands. They vary from low-growing shrubs to trees, with leaves ranging from large and unlobed to small, deeply lobed and intricately serrated.

The research was conducted by a large international team led by Vanessa C. Bieker of the Royal Botanic Gardens, Kew, and Professor Michael D. Martin of the NTNU University Museum. The researchers included scientists from the University of California, Davis; the University of Copenhagen; the Charles Darwin Foundation in the Galápagos; the University of Georgia, Athens; the University of British Columbia; and several other institutions. Their paper was published on 16 April 2026 in the journal Nature Communications.

Using population-level genomic data from 396 individual plants representing all 15 recognised Scalesia species, together with measurements of leaf shape and gene-expression data from different developmental stages, the researchers reconstructed this remarkably rapid adaptive radiation.

They found that much of the plants’ morphological and ecological diversity arose through natural selection acting upon shared genetic variation inherited from the founding population. That ancestral variation was unusually rich, partly because Scalesia has an allopolyploid history—its ancestors combined chromosome sets derived from different ancestral lineages.

One particularly revealing finding concerned lobed and serrated leaves, which are thought to help plants cope with hot, dry conditions by reducing water loss and improving heat dissipation. These leaf forms evolved independently several times in different branches of the Scalesia family tree. Yet natural selection did not repeatedly alter the same gene. Instead, it acted upon different regulatory genes within the same developmental network controlling leaf growth and polarity.

This is a striking example of parallel evolution: similar environmental pressures producing similar adaptations in related lineages, but through different genetic routes. Evolution does not require a single “master gene” for a complex characteristic. Selection can modify different components of an interacting genetic network and arrive at broadly similar phenotypic results.

The finding also sits awkwardly with the traditional creationist claim that common design is evidence of a common designer. If superficial similarity is supposed to reveal the hand of a designer, why did this supposed designer repeatedly alter different parts of the same developmental network to produce essentially the same leaf shape? Evolution explains both the similarity of the outcome and the untidy diversity of its genetic foundations. “Design” merely applies a label to the result.

Moreover, the researchers discovered unexpectedly large genetic differences among geographically isolated populations currently classified as members of the same species. Some have remained separated for long periods and may already constitute distinct evolutionary lineages. In other words, speciation may be under way even though the differences are not yet obvious enough for a casual observer to recognise them. The authors consequently recommend that isolated populations should be treated as separate conservation units.

There has been no sudden transformation and no magical appearance of a new “kind”. Instead, there is inherited variation, geographical isolation, differential selection, genetic divergence and the gradual emergence of separately evolving lineages.

Evolution is a process, not an event.

Evolution’s Raw Material^ Standing Genetic Variation and Allopolyploidy. Evolution does not always have to wait for a useful new mutation to appear. Populations normally contain a reservoir of genetic differences accumulated over many previous generations. This is known as standing genetic variation.

These differences arise through mutation, recombination, migration and hybridisation. Many may have little effect under existing conditions, but their importance can change when the environment changes. A variant that was previously neutral—or even slightly disadvantageous—may then improve survival or reproductive success.

Natural selection does not produce a required mutation because an organism needs it. Instead, it changes the relative frequencies of variants already present or generated without foresight. If individuals carrying a useful variant leave more descendants, that variant becomes more common in subsequent generations.

Adaptation from standing variation can occur comparatively quickly because the useful allele may already be carried by numerous individuals. A new mutation, by contrast, begins as a single copy and may disappear through chance before selection can increase its frequency.

What is allopolyploidy?

Most animals and many plants are diploid, possessing two sets of chromosomes—one inherited from each parent. Polyploid organisms possess more than two complete chromosome sets.

Allopolyploidy occurs when two related species hybridise and their chromosome sets become combined and duplicated. An ordinary hybrid may be sterile because its chromosomes cannot pair correctly during the production of eggs or pollen. Chromosome duplication can give each chromosome a corresponding partner, restoring fertility and creating a reproductively distinct lineage.

Allopolyploidy is especially important in plant evolution. By bringing together two previously separate genomes, it can:

greatly increase the amount of inherited genetic variation;

provide additional copies of genes that can acquire new or specialised functions;

allow different versions of a gene to be used under different environmental conditions;

alter gene regulation and interactions between developmental pathways; and

produce immediate reproductive isolation from the parental species.

Gene duplication does not guarantee evolutionary novelty, and many duplicate genes are eventually lost or disabled. Nevertheless, the additional genetic material creates opportunities for evolutionary change that would not exist in a genome containing only one copy of each gene.

The Scalesia example

The ancestral lineage that colonised the Galápagos carried unusually high genetic diversity associated with an allopolyploid history. Consequently, its descendants inherited a rich collection of genetic variants upon which natural selection could act as populations encountered the different environments of the islands.

Much of the remarkable diversity among the 15 recognised Scalesia species therefore arose from different uses of shared ancestral variation. The species did not require an entirely new genetic toolkit for each habitat. Natural selection modified different components of the toolkit they had inherited.

This is particularly apparent in the repeated evolution of lobed and serrated leaves. Similar leaf shapes arose independently in several lineages, but selection acted upon different regulatory genes within the same developmental network. Similar environmental problems therefore produced similar visible adaptations without requiring identical genetic changes.

Standing genetic variation supplied the alternatives; allopolyploidy helped preserve a particularly diverse supply of them; environmental conditions determined which variants improved reproductive success; and geographical isolation allowed the populations to diverge.

Nothing anticipated which variants would be needed. There was no genetic instruction inserted because a plant required it and no plan directing each population towards a predetermined result. There was inherited variation, differential reproduction and selection—evolution working with whatever material history had made available.

The paper in Nature Communications was accompanied by an article in Norwegian SciTech News, the research news service of NTNU and SINTEF:

Botany’s answer to Darwin’s finches shows evolution in real time
A new study reveals how a remarkable group of plants on the Galápagos Islands developed their diverse leaf shapes – offering unique insight into evolution at the genetic level.
The Galápagos Islands hold an iconic place in the history of evolutionary biology. When Charles Darwin landed 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. Their different appearances were the result of beaks adapted to different diets.

These finches became a key argument for Darwin’s theory of evolution by natural selection – that species can change in ways shaped by the environments they inhabit.

More than 150 years after Darwin’s work on the Galápagos transformed our understanding of life on Earth, these islands continue to reveal new biology.

Professor Michael D. Martin, co-corresponding author.
Department of Natural History
NTNU University Museum
Norwegian University of Science and Technology (NTNU)
Trondheim, Norway.

[Professor Michael D. Martin] is part of a large international team of researchers from the Royal Botanic Gardens, Kew; the University of California, Davis; the University of Copenhagen; the Charles Darwin Foundation, Galápagos; the University of Georgia, Athens; the University of British Columbia; and several other institutions. Together, they 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.

Vanessa Bieker, first-author
Royal Botanic Gardens
Kew, Richmond, Surrey, UK.

The genus Scalesia is evolutionarily young. All species living today emerged within the last one million years. Yet they have managed to adapt to the wide range of environments found across the islands – from dense, humid highland forests to dry, open lowlands.

Serrated leaves of Scalesia affinis (radiate-headed scalesia).

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.

Professor Michael D. Martin.

Lobed leaves, with their sometimes complex and serrated edges, are thought to help the plants survive in hot, dry environments by reducing water loss and dissipating heat. 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 analyzing the complete genomes of all known Scalesia species, the researchers discovered that lobed leaves evolved several times – each time in different parts of the Scalesia family tree.

Close-up of serrated leaves of Scalesia affinis (radiate-headed scalesia).

Photo: Michael Martin, NTNU University Museum.

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. This 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.

Vanessa Bieker.

This gives researchers important insight into how complex traits can arise again and again in nature.

Evolution still in progress

In addition to uncovering how these plants evolved, the researchers found that evolution is still ongoing.

Herbarium sheet with Scalesia incisa collected by Charles Darwin during the voyage of the Beagle in the Galápagos Islands from 1831-1836.

Photo: GBIF, Cambridge University Herbarium (CGE) collection, CC BY-NC 4.0

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.

Professor Michael D. Martin.

The researchers therefore argue that each isolated population should be treated as its own conservation unit – a shift that could influence 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.

Vanessa Bieker.

She added that Darwin also collected many plants on the Galápagos. Seventy‑eight of them were later used to describe species entirely new to science – including four species of Scalesia.

Publication:
Bieker, V.C., Li, S., Cerca, J. et al.
The genomic basis of adaptive leaf variation in the Galápagos giant daisies. Nat Commun 17, 5319 (2026). https://doi.org/10.1038/s41467-026-71865-3

Abstract
Scalesia (Asteraceae) is the largest endemic plant genus of the Galápagos archipelago and an example of adaptive radiation. While Scalesia species are highly varied in habit and morphology, most remarkable is their variety of leaf shapes, especially in the differential presence of leaf lobing/serration, a derived trait that evolved multiple times as a likely adaptation to the islands’ hot and dry equatorial climate. Using population-level genomic data from 396 individuals representing all 15 recognized Scalesia species, we characterize this young radiation (around 1 million years ago), and reveal that their substantial morphological divergence and ecological specialization are primarily based on shared genetic variation. To further elucidate the repeated adaptive evolution of leaf lobing in Scalesia, we integrate genomic and leaf morphometric data, with transcriptomes from different developmental stages, and conclude that leaf lobing evolved through diversifying selection. Natural selection occurs independently on different regulators in the pathway controlling development of adaxial-abaxial leaf polarity, highlighting the importance of the founder populations’ high genetic diversity maintained via allopolyploidy. Finally, our findings have implications for the conservation of Scalesia’s threatened biodiversity, as unexpectedly high intra-specific genetic structure and long-term isolation among populations indicate widespread nascent speciation.

Bieker, V.C., Li, S., Cerca, J. et al.
The genomic basis of adaptive leaf variation in the Galápagos giant daisies. Nat Commun 17, 5319 (2026). https://doi.org/10.1038/s41467-026-71865-3

Copyright: © 2026 The authors.
Published by Springer Nature Ltd. Open access.
Reprinted under a Creative Commons Attribution 4.0 International license (CC BY 4.0)

What the researchers found in Scalesia is not merely evidence that evolution happened in the past, but evidence that it is continuing today. Inherited variation, natural selection and geographical isolation have already produced 15 recognised species, while the pronounced genetic separation of some populations suggests that further species are now beginning to emerge.

The inevitable creationist response—that they are “still daisies”—only exposes a misunderstanding of evolution. Descendants never escape their ancestry: a new Scalesia species remains a member of the daisy family, just as humans remain apes and birds remain dinosaurs. Evolution adds new branches to the tree of life; it does not detach them from the branches upon which they arose.

Nor does the genomic evidence resemble the work of an engineer repeatedly applying a standardised solution. Similar lobed leaves evolved through changes to different regulators within the same inherited developmental network. This historically contingent genetic patchwork is exactly what we should expect when natural selection works with whatever variation happens to be available. Invoking an intelligent designer explains neither why the routes differed nor why an allegedly intelligent process needed to duplicate, modify and repurpose inherited material in the first place.

Almost two centuries after the voyage of HMS Beagle, the Galápagos Islands continue to teach the same lesson: species are not fixed, “kinds” are not biological realities, and apparent design can arise through entirely natural processes. The islands have not stopped evolving merely because creationists refuse to recognise evolution while it is happening.

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