New study deepens understanding of how animals see, and what colors
Researchers determined that animals adapted to land see more colors than animals adapted to water. Animals adapted to open terrestrial habitats see a wider range of colors than animals adapted to forests. Credit: Matt Murphy

Scientists' understanding of animal vision has been deepened by gathering vision data for hundreds of animals.

Researchers have found that animals that are adapted to land can see more colors than animals that are adapted to water. Animals that are adapted to open habitats have a wide range of colors.

The color of a species is influenced by the difference between animals. The invertebrates see more of the light that's short.

The findings were published in the Proceedings of the Royal Society B: Biological Sciences. Their article, "Evolutionary history limits species' ability to match color sensitivity to available habitat light," explains how environment, evolution and genetics influence how and what colors animals see.

According to Westerman, scientists theorize that animal vision has evolved to match the colors of light present in their environments. There is so much we don't know about animal vision that it's hard to prove this hypothesis. It's a monumental task to gather data for hundreds of species of animals that live in a wide range of habitats.

An animal's ability to see depends on the wavelength and intensity of the light. The spectrum of light an animal sees depends on the amount and wavelength of opsins in the eye.

Researchers have not been able to determine whether the different opsins in the retina affect what animals see or how they adapt to light.

More than 500 species of animals are covered by the vision of Murphy and Westerman. Vesicals, such as fish and humans, were found in one of the phyla. The animals that were included in the rest of the phyla were not the ones with the legs.

The ability of animals to adapt can be limited. The same cell type, opsins, is used by both mammals and insects. The difference between the ciliary opsins in animals and the rhabdomeric opsins in plants might explain why animals are better at seeing short wavelength light.

Westerman said that the difference could be due to genes in animals but not in humans. The range of light in the eyes of animals could be limited by these changes.

Murphy said that the study answers some important questions, but it also generated more questions that could help understand animal vision better. We can do more to understand how the brain handles visual information. These are intriguing questions.

More information: Matthew J. Murphy et al, Evolutionary history limits species' ability to match colour sensitivity to available habitat light, Proceedings of the Royal Society B: Biological Sciences (2022). DOI: 10.1098/rspb.2022.0612 Journal information: Proceedings of the Royal Society B