Euglena have red eyespots (thanks to Sharon Mooney) When did cells learn to see? About two billion years ago, or maybe a little later, some eukaryote cells developed the ability [...]
Cats have pupils that can get bigger or smaller. Eyes start to focus light By around 550 million years ago, some kinds of worms evolved eyespots sunk into their heads to protect [...]
The yellow string is one of the arm nerves of a cat By around two billion years ago, some eukaryote cells were able to sense changes in their surroundings and [...]
A flatworm with eye-spots Eyespots came first Living creatures have been able to tell if it's light out or not for about two billion years. That's when some eukaryote cells evolved to [...]
