The bloodybelly comb jelly is nearly invisible in the deep sea, where red animals appear black and blend into the dark background. Scientists think the jelly’s blood-red belly helps mask bioluminescent light from prey it swallows—so it won’t become a snack for another deep-sea predator!
In other words, an encounter with an octopus can sometimes leave you with the strong feeling that you’ve encountered another mind.
But that mind—if mind it is—has evolved along a route entirely different from the one that led to our own. The most-recent common ancestors of humans and octopuses lived about 600 million years ago, early in the evolution of animal life. Although much about our joint ancestors is obscure, they were probably small wormlike creatures that lived in the sea. This makes octopuses very different from other animals we suspect of sentience, such as dolphins and dogs, parrots and crows, which are much more closely related to us. In the words of Peter Godfrey-Smith, “If we can make contact with cephalopods as sentient beings, it is not because of a shared history, not because of kinship, but because evolution built minds twice over. This is probably the closest we will come to meeting an intelligent alien.”
