If you’ve ever been lost on a trail while in the company of a directionally-savvy dog, then you’ll have no trouble believing what science is calling a breakthrough discovery: dogs and other mammals may possess a “compass” in their eyes.
Earlier this year, researchers gathered at the Max Planck Institute in Germany to study the eyes of 90 mammals in the hope of finding a light-sensitive molecule called cryptochrome 1a. In migratory birds, these molecules are found in the blue cone receptors in the eye. Cryptochrome helps birds - as well as other migratory mammals and insects - orient themselves and navigate, by tracing the Earth’s magnetic fields.
The scientists’ discovery was surprising: many of the carnivorous mammals they studied - including dogs, certain primates, and bears - did in fact possess the cryptochrome 1a molecule. Other animals, like cats, did not.