If Humans Go Extinct, Octopuses Are Capable of Building the Next Civilization

With brains that process information almost like computers, sea creatures are already using their advantages and are ready to socialize. But before they can take over the world, they need to change a few things.

By analyzing the fossil record, scientists found that species on Earth have already experienced five mass extinctions since the planet's existence, including the last mass extinction, which occurred about 65 million years ago and wiped out dinosaurs. Now researchers believe humanity is in the midst of one more.

Human impacts on biodiversity - both habitat loss and the effects of anthropogenic climate change - have resulted in irreversible damage to wildlife, according to a 2023 article in the journal PNAS. Fifty percent of living species could disappear by 2080 if humans do not curb greenhouse gas emissions and deforestation, according to an article published in 2022 in Nature.

It is possible that sudden events, such as a nuclear war or even a collision with a huge asteroid, could wipe out these species, including humans and apes, even sooner. This raises the question: if humanity's days are numbered, what species might rise from the ashes to take the place of humans?

According to biologist Tim Coulson, a PhD candidate studying ecology and evolution at Oxford University, unexpected successors can be found on the menu of modern sushi.

"There are very many species of octopus, not just one species like humans.... and they live in a wide variety of habitats, including deep ocean and coastal areas," says Coulson. "Although some populations are underdeveloped, I think others have the ability to survive, spread and diverge over evolutionary time to colonize a wide variety of habitats, including coastal."

While the idea may seem improbable at first glance (and Coulson is the first to admit that there are many scenarios in which octopuses don't come to take over), this isn't the first time an ocean-dwelling species has taken advantage of terrestrial extinctions to adapt and evolve. According to Andrew Whiten, PhD, a professor of zoology and psychology at the University of St. Andrews, this is how the mammalian ancestors of humans made significant advances.

"It's possible to imagine any number of scenarios where, in some apocalyptic posthuman world, other species currently quietly going about their lives become dominant on the planet, just as our small mammal ancestors paved the way for us humans after the extinction of the dinosaurs," Whiten says.

According to Coulson, octopuses already have a number of advantages that could set the stage for the development of more advanced intelligence. For example, some octopus species have used wildlife aids, such as wearing coconut shells as armor and shelter, and have used adaptations to successfully navigate mazes in laboratory settings.

Coulson says captive octopuses have even been seen escaping from their tanks to "visit" other octopuses in neighboring tanks. According to Andy Dobson, PhD, professor of ecology and evolutionary biology at Princeton University, the kind of intelligence that makes this possible is somewhat different from that endowed to humans. Octopus intelligence can be almost computerized.

"Octopuses appear to have a highly developed nervous system, although I'm not sure we would call the dense cluster of neurons connecting their eight limbs and huge eyes a brain, [it's] more like a massive data processing center," says Dobson. "Their intelligence comes from having multiple limbs and two huge eyes that allow them to sense their environment."

While octopuses aren't the only species that demonstrate a high level of intelligence, Coulson says agility is a key attribute that sets octopuses apart. "They are very agile and are able to use their eight limbs to manipulate a wide variety of objects," he says. "Although crows and various birds are capable of bending pieces of wire in their beaks or dropping rocks into the water to raise the water level and get food, they don't have the agility that octopuses have."

For coastal octopuses, Coulson believes this is possible by harnessing tidal energy. Deep-sea octopuses may be able to harness the energy of hydrothermal vents, but this is likely to prove more challenging.

With increasing intelligence and access to energy, octopuses must face the biggest obstacle to evolutionary progress: sociality. Octopuses have a reputation for being loners and even sometimes cannibals. According to Peter Godfrey-Smith, PhD, professor of history and philosophy of science at the University of Sydney, in order for octopuses to congregate in any type of city, this behavior had to undergo significant changes.

"Octopuses are not well suited to creating a humanoid society because of their social habits - they are unlikely to develop culture," Godfrey-Smith says. "When I talk about 'culture', I mean the ability to learn from other individuals in a society..... For octopuses, the first step they need to take is to become more social, and to raise their cubs differently."

Godfrey-Smith explains that octopuses inherit very little culture - at least as humans experience it - from their parents at birth because they have little or no involvement in their upbringing. To create a closer-knit society, he says, octopuses may have to develop more intergenerational bonds.

Since such social changes have not yet occurred in the last 50-100 million years of octopuses' existence, it is unlikely that the situation will change anytime soon. But in their defense, scientists say that in the last decade they have noticed that some octopus species may be more social than others, these octopuses live in groups of ten or more individuals.

Unfortunately, it is very likely that human impacts on octopuses will limit their evolutionary chances from the start. Pollution, rising ocean temperatures, overfishing and microplastic pollution may have already caused irreparable damage to octopuses.