COLOUR AND VISION

In the Pre-Cambrian era there were no image-forming eyes, and organisms just had basic light receptors to tell the difference betwee n light and dark. For colour to exist there needs to be light, an image-forming eye and a brain to process the data.Around 543 milli on years ago roughly six major groups of animals existed. Approximately 20 million years later, a blink of the eye in evolutionary h istory, there were 38 groups - similar to the number that exists today. This dramatic increase may be explained by the evolution of image-for...[Llegir més]