Which animal will replace humans as Earth's dominant species? This scientist has an idea

The idea of life continuing on Earth without humans has a way of catching our attention. Our species has spread across land and sea, altering the planet in countless ways.

Still, Earth’s history shows that no species lasts forever. It can be sobering to consider a future without us, but it also sparks plenty of curiosity about what might follow in our absence.

Human beings have been at the center of ecological change on Earth for thousands of years. Our inventions and communities have reshaped forests, oceans, and even the atmosphere.

Yet many researchers say nature will adapt once we are gone. This leads to questions about who – or what – would occupy our spot.

Earth after humans

Professor Tim Coulson from the University of Oxford has spent years studying biology and evolution. He believes our disappearance could open the door to surprising new species that take over Earth’s ecological roles.

In his book, The Universal History of Us, he traces life’s entire history and zeroes in on a single, striking prediction about what might come next.

One of his main themes involves evolution, which he describes as the “gradual change in living organisms over time as they better adapt to their environments.”

He emphasizes that “most mutations are harmful, but a few provide a survival or reproductive advantage.” Because genes are heritable, these beneficial mutations become more common over generations.

Natural selection and change

Mutations, in Coulson’s view, drive life forward despite the risks. Yet he reminds readers that no species is permanent.

“Extinction is the fate of all species, including humans, although let’s hope our demise is far in the future.”

That message can feel unsettling. But it also serves as a reminder that every life form, no matter how successful, eventually faces an endpoint.

Coulson’s outlook stems from years of research into how species emerge, survive, and sometimes vanish. “I started to wonder what species might take our place if humans, and our close great ape relatives, were to die out,” he says.

Once humans are removed from the picture, Earth’s ecosystems could find balance again, which might allow new creatures to fill the empty slots.

New forms of intelligence emerge

Nobody knows if the next ruling life form would mirror humanity. Coulson proposes that “new forms of intelligence and complexity could emerge in unexpected ways.”

This opens the possibility that a future species might come up with solutions and technologies unlike any we can picture right now.

Some believe that primates are the likeliest successors, but Coulson raises doubts.

“Primates depend heavily on strong social networks,” he explains, along with the idea that “they engage in activities like hunting, grooming, and defense, which are essential for their survival. These constraints might help them struggle to adjust to a world undergoing dramatic ecological shifts.”

Potential successor to humans on Earth

In place of our primate relatives, Coulson offers a contender that many might find startling: the octopus. He points to their cleverness and adaptability.

“Their ability to solve complex problems, communicate with one another in flashes of color, and manipulate objects suggests that, given the right environmental conditions, they could evolve into a civilization-building species.”

He adds, “their advanced neural structure, decentralized nervous system, and remarkable problem-solving skills make several species of octopus well suited for an unpredictable world.”

Octopuses already have a reputation for being creative and a bit mischievous.

“Some individuals even escape from their tanks at night in some research centers, visiting those of their neighbors, believe it or not,” Coulson says. They are known to use tools, open jars, and display signs of curiosity.

Life underwater

If humans were gone, oceans might become even more central to Earth’s future. Though land-based creatures have typically held top positions on the food chain, Coulson notes a critical challenge for octopuses.

“Octopuses are unlikely to adapt to life on land due to their lack of a skeleton, which makes swift and agile movement out of water challenging,” he explained.

“With evolutionary advances, it is possible, if not probable, that they might develop ways to breathe outside of water and eventually hunt terrestrial animals like deer, sheep, and other mammals – assuming they have survived the catastrophic event that drove humans extinct.”

That sounds extreme. Yet Coulson is simply highlighting how evolution can lead life down paths that seem impossible at first.

What would octopus-Earth look like?

Octopuses might build underwater habitats, find new ways to interact with their surroundings, and even reach beyond the waves one day.

“Would octopuses build vast underwater cities and come onto land wearing breathing apparatus to shoot a deer? We’ve no way of knowing,” he says.

No one predicted that ancient primates would slowly turn into bipedal humans with advanced technology.

Coulson believes that “random mutations, unforeseen extinction events, and population bottlenecks can all significantly influence the trajectory of evolution.” This means the future is wide open, shaped by countless variables that scientists can’t fully predict.

Impossible to know, fun to think about

“The future of life on Earth is shaped by countless variables,” he points out. The path of evolution might take strange turns. Some scenarios might never pan out. Others could surprise us by unfolding in real time.

“But could octopuses replace humans – and potentially also primates – if they were to die out? Absolutely. They could become the brains of the sea.”

For now, it remains an intriguing thought experiment to imagine aquatic invertebrates overseeing a planet once dominated by upright mammals.

Imagining Earth without humans

Coulson does not claim that this outcome is inevitable. Instead, he suggests it as a lesson in how nature might rearrange itself without us.

Earth’s past is packed with examples of life enduring massive upheavals. It’s possible that intelligence, in some form, might spring up long after humans are gone.

His book underscores evolution’s capacity to produce forms and behaviors that seem strange from our perspective.

This speculation encourages us to think about the delicate nature of our own hold on the planet. Our species is part of a story that began ages ago, and life will keep moving forward, one step at a time.

The full interview was published in The European.

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