Jewel Beetles Evolve to See New Colors by Duplicating Their Genes

Published:16 Apr.2023 Source:University of Minnesota

New research led by Camilla Sharkey, a postdoctoral associate at the Wardill Lab in the College of Biological Sciences, investigated the complex evolutionary history of jewel beetles’ vision. Previous research by Dr. Sharkey has shown that before the evolution of modern beetles, their ancestors lost the ability to see blue light around 300 million years ago. This may have been the result of the beetle ancestor becoming nocturnal or living in low-light conditions. Later, as beetles diversified, they evolved duplicates of the ancestral genes that allow them to see the UV and green spectrum. These duplicate genes could further evolve, making new parts of the color spectrum visible and allowing more complicated and diverse color signals to be seen.

Researchers wanted to know if the duplicate genes have evolved, allowing beetles to see colors that their ancestors could not. Since jewel beetles are difficult to keep in a lab, they copied the genes and inserted them into fruit flies, replacing their normal visual genes. Using electrophysiology, they tested the color sensitivity each gene produced in the flies. They then looked for genetic changes that might underlie the shifts in color sensitivity using 3D protein modeling. The study found that: Jewel beetles have evolved additional blue and orange sensitivity by duplicating and evolving their UV and green visual genes. This enables complex tetra-chromatic color sensitivity to UV, blue, green and orange wavelengths of light, similar to the color sensitivity of colorful birds.