jewel beetles and the color they see—nature’s evolving palette
Nature hosts some truly curious animals, and jewel beetles are among the most striking. These insects perceive the world with a vision that is far more colorful than their own freshly formed shells. Over thousands of years, they have acquired an evolutionary edge by tuning their sight to fit their environment and needs, making them one of the most color-sensitive creatures in the natural world.
Their path has not been smooth. Long before today’s diverse insect lineages emerged, nearly 300 million years ago, early ancestors struggled with color vision. They had lost the ability to see blue light, because their nocturnal lives in dark caves and burrows demanded different visual tools. The need to navigate in near darkness meant blue light vision wasn’t advantageous, and it faded from their sensory toolkit.
Yet life persisted and diversified. Insects spread into countless habitats, adapting in remarkable ways. Scientists observed that gene copying and modification played a key role in expanding how these creatures perceived color, pushing visible perception toward greens and, crucially, toward ultraviolet light beyond human reach.
Duplication of a second gene
What if the evolutionary story could continue beyond these initial steps? What if insects kept duplicating the genes related to vision? This question drew the attention of researchers from the University of Minnesota, who collaborated with colleagues across several U.S. centers. They set out to determine whether gene duplication continued after initial changes and whether the expanded genetic toolkit broadened the color field beyond ancestral limits. The study was led by Camila Sharkey of the University’s School of Biological Sciences, with findings published in Science Molecular Biology and Evolution.
Because jewel beetles are difficult to maintain in laboratory settings for direct observation, the team inserted the beetle’s genes into fruit flies and replaced the DNA segment responsible for vision. Through electrophysiology, which examines the electrical properties of cells and tissues, researchers confirmed sensitivity to specific colors in these genetically modified flies. After gathering data, they built a 3D model of the protein to explore potential genetic changes further.
With closer genetic scrutiny, scientists found a surprising result: the insects regained blue vision their distant ancestors had lost. The gains did not stop there; they also added orange to the spectrum they could perceive. Across the jewel beetle samples studied, four distinct gene types were present, indicating a complex and robust color sensitivity common to the group.
This discovery has opened up a broad field of inquiry. The next step is to assess whether it is possible to predict the exact color range that a given animal could see based on a single gene, and to determine whether these sensory properties help insects manage pests or support pollination, ultimately influencing crop outcomes.
Sharkey hopes the work will illuminate the molecular basis of color sensitivity in jewel beetles and, more generally, allow researchers to predict an insect’s color sensitivity from its genetic sequence.
Citation note: The study is discussed in the journal Science and related works in Molecular Biology and Evolution.
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