Human beings are different from other animals on earth. Other animals don't cook their own food, they don't invent smartphones and they don't lose all their Bitcoins when they can't find a way to access their wallet.
What if humans suddenly disappeared? What other animals could take our place in the event of our extinction? What other animals would be able to create large and complex societies like ours?
After us, who could benefit from our extinction?
With new technologies and our understanding of evolution, we can make predictions about the short-term future. For example, we can predict that in the event of a very close extinction of the human race (would Thursday be okay with you?) the climate change it would push many species towards drought resilience to survive. Even cold-adapted species would become extinct: polar bears and penguins would follow us into extinction a short distance away.
It is possible that there would be some convergence, understood as the evolutionary process through which two unrelated organisms eventually develop similar characteristics.
An example? The shape of the fish, complete with stabilizing fins that make them suitable for life in the water. Well, dolphins have an anatomy very similar to that of fish even though, unlike the latter, they are warm-blooded mammals that breathe air. And they have a very distinct evolutionary history.
Manual skill, our stuff? And the monkeys?
One thing that makes us special is in our hands, and it doesn't just say it this research from the University of Manchester. We can build cities, change our surroundings and take selfies. To do the same thing, the “lucky” survivors of our eventual extinction would have to have opposable thumbs, or at least something similar.
Chimpanzee, Bonobo, are you our heirs? In fact, they are already our closest living relatives, and already have opposable thumbs that they use to make tools in the wild. It is possible that with the extinction of humans they could replace us: then it would be “Planet of the Apes”.
A bit like we ourselves did when we survived the Neanderthals about 40.000 years ago: says a 2021 study published in Nature. That said, it would likely take hundreds of thousands or even millions of years for these apes to develop the ability to create and use sophisticated human-like tools and order pizza on an app.
Unfortunately we are very similar: any disaster powerful enough to cause human extinction also risks wiping out chimpanzees. This shines a light on another possible candidate for our succession: birds.
Imagine if I wrote “Hitchcock” right without Googling.
With the extinction of land dinosaurs 66 million years ago, mammals began to fill their vacated slots. If humans disappeared, birds could take our place as intelligent and skilled animals.
Some birds, such as crows and ravens, have intellects that rival even chimpanzees, according to research published in 2020 in the journal Science. Again according to a study published in Science some birds may use their skillful feet and beaks to shape the wire into hooks. An African Gray Parrot (Psittacus erythacus) properly trained can learn up to 100 words and do simple calculations, including understanding the concept of zero. You didn't know this, admit it.
Birds can gather in large groups, but I cannot imagine large metropolises made of nests: perhaps because it is impossible, perhaps because I simply cannot. Come on another candidate!
There is another group of animals that may be enjoying our extinction. An animal extremely skilled at manipulating objects with its limbs.
All eight.
In terms of capacity, octopuses are probably the smartest non-human animals on Earth. They can learn to distinguish between real and virtual objects, according to 2020 research published in The Biological Bulletin, and they can even design their environment by removing unwanted algae from their burrows and barricading the entrance with shells, according to a study in the journal Communicative and Integrative Biology. They are even known to live in communities of some kind.
Octopuses would have difficulty adapting to life on land. Vertebrates have iron in their blood cells, which bind to oxygen very easily. In contrast, octopuses and their relatives have copper-based blood cells. These molecules still bind to oxygen, but less easily, and as a result, octopuses are confined to oxygen-saturated waters. I doubt they would be able to come out and found a Rome for octopuses.
Who remains as a candidate to take our place after our (eventual) extinction?
My 50 cents are on social insects. Ants and termites. They are more resistant than us, monkeys, birds and even cephalopods. Other than extinction, they have been around for 480 million years and in all this time they have learned to do everything: swim, dig, build.
Nothing resembles our organization like an ant colony (we would even have a little something to learn, in some cases). Ants raise mushrooms, according to research published in 2017 in the journal Proceedings of the Royal Society B, and termites can communicate over long distances within their colonies using vibrations, according to a 2021 study in the journal Scientific Reports. In case of extinction, these funny guys could play bingo.
Of course, all of this is speculation; it is virtually impossible to truly predict how evolution will unfold on a geological time scale. The further you go with the forecasts, the more variables intervene.
It cannot be predicted whether another species will develop human-level intelligence or the desire to build cities. It could happen, but not without millions of years of selective pressure.
