Why the octopus could inherit the Earth after humans

HostIt's kind of fun to wonder what the world would look like if humans just packed up and left. We often think a monkey or a smart bird might step up to fill our shoes, but there's this one creature in the sea that feels like a much better bet for the job.

HostWhat's it about the octopus that makes people think they could be the ones to take over?

GuestThe way they think is the first thing that sets them apart. Imagine if your arms had a mind of their own. For an octopus, that's pretty much the reality. Most of their brain power isn't in their head. It's spread out through their body, mostly in those eight arms. They have more than five hundred million brain cells, but about two thirds of those are in their limbs. This means an arm can taste, touch, and move on its own without waiting for the head to tell it what to do.

HostThat sounds like it would be a nightmare to control. If my left hand wanted to eat a sandwich and my right hand wanted to tie my shoe at the same time, I would never get anything done. How's that an advantage?

GuestIt works because they don't try to micromanage. The head gives a general order, like, go find a crab, and then the arms handle the small details of how to move over the rocks and reach into the cracks. It's like having eight smart helpers that you don't have to watch every second. This lets them solve very tricky problems that other animals can't touch. They have been seen opening jars from the inside, or even sneaking out of their tanks in big sea labs to eat the fish in the tank next door before going back home. They're great at figuring out how things work.

HostBut even if they're smart, they're still stuck in the water. We built our world with fire and metal. You can't have a forge or a factory at the bottom of the ocean. Without that, how do they ever move past just being clever hunters?

GuestWe might be looking at it through a human lens. They don't need fire to build things the way we do. They're already great at using what they find in their world. Some octopuses carry around coconut shells to use as a portable house or a shield when they're out in the open. If they had more time and a reason to stay together, they could start building structures out of stones or bone. They have the grip and the brains to use tools in ways other sea animals can only dream of. They don't need to melt metal to be a force on this planet. They just need to keep solving problems with what's already there.

HostI see the tool use, but they still seem like loners. To build a world, you usually need to work together and pass on what you know. I thought octopuses mostly kept to themselves.

GuestFor a long time, we did think they were solo acts. But recently, we found a spot off the coast of Australia that people call Octopolis. It's a place where many octopuses live close together. They fight, they talk to each other through colors and skin patterns, and they even throw shells and silt at each other when they get annoyed. They're starting to show the kind of group life that leads to bigger things. They're learning how to live in a crowd.

HostStill, they only live for a few years. It seems impossible to build anything lasting when you die so young. Most of them only get one or two years before they're gone. How can a species take over the world if every single one has to start from zero?

GuestThat's the big hurdle. In most cases, the mother dies right after the babies hatch. There's no school, no talking, and no stories passed down from the old to the young. If they lived for thirty years instead of two, they would be terrifying. But here is the thing about how life changes over time. All it takes is one small shift in their code to let them live longer. If that happens, and they start teaching their kids what they learned, they could go from being smart sea creatures to a real power very quickly.

HostI'm not sold on that. Just living longer doesn't mean they'll suddenly start writing books or building underwater cities. It feels like we're projecting our own path onto a creature that's happy just eating crabs.

GuestIt's not about them becoming human. It's about their potential. They have no bones, so they can fit into any space. They can change their skin to look like a rock or a plant in a split second. They have three hearts and blue blood. They're basically an alien life form already living here. If the space we take up suddenly opened up, they have the brain power and the physical tools to fill it. They're the only ones with the hands to do it.

GuestIf one group of octopuses started staying alive just long enough to teach their kids the best way to open a shell, the whole balance of the ocean would shift in a few generations.

HostCoconut shells might be the first step toward something much bigger if they ever find a way to beat the clock.