Ultraviolet (UV) radiation is usually seen as destructive to life. It causes skin cancer, gives cataracts to healthy eyes, and causes sunburns. We are generally protected from ultraviolet radiation by the ozone layer in our upper atmosphere. However, there is a latitude effect with higher levels of ultraviolet radiation reaching the upper latitudes, primarily because of the thinning of the ozone layer. Reindeer live in these upper latitudes, and researchers have been studying how they handle this increased ultraviolet exposure. In the process of this study it has been shown that reindeer actually use the ultraviolet to enhance their survival. Researchers have discovered that the reindeer eye is actually designed with photoreceptors that can sense and process ultraviolet radiation.
The reindeer’s ability to see ultraviolet light allows them to avoid predators and find food. The reindeer's main predator is the wolf and wolf fur absorbs ultraviolet light. In a snowy environment where the ultraviolet rays are reflected, the reindeer can see the wolf clearly.
In addition to avoiding predators the reindeer is assisted in finding food. Lichen is the primary winter food of the reindeer, and it also absorbs ultraviolet radiation so the reindeer can find it in the snow.
Still a mystery to scientists is how the reindeer avoids eye damage from the UV rays. Light exposure causes humans to lose 20 to 30 percent of their central photoreceptors in the course of life. If we could discover how the reindeer avoid damage to their eyes in the UV-reflective environment we might be able to avoid age-related macular degeneration.
We are told in the Bible that “we can know there is a God through the things he has made” (Romans 1:19 – 22). The reindeer is a great example of design aimed at aiding survival in a harsh environment. Source: Scientific American, August 2011.
Picture credits:
Elen Schurova, en.wikipedia.org/wiki/File:Reindeer_pulling_sleigh,_Russia.jpg