The 700 million year evolution of eyesight

Previously, experts have always argued about the exact time when ancient species developed the first primitive ability to see light.

Accordingly, scholars divided into two factions, with one side saying that sponges or jellyfish are the first species to obtain opsin, a light-sensitive receptor protein group in the retina photoreceptors.

In an effort to find the most accurate answer, a team of experts from the University of Bristol (UK) studied a group of newly decomposed sponges called Oscarella carmela , and Cnidarian jellyfish. These are two groups of animals that are thought to possess the first eyes of the world. Using a computer model to get a close-up view of the evolution of opsin, Dr. Davide Pisani of the university analyzed and tested every hypothesis about the development process of opsin according to the hypothesis so far.

Analysis results show that opsin appeared about 700 million years ago. However, early opsin was still considered 'blind' until undergoing significant gene changes during the next 11 million years before the first light was seen.