What species would replace us?

Consider this thought experiment: Imagine the potential for animals to become the dominant species if humans were to go extinct. It's a difficult question, as humans possess unique attributes such as high intelligence, fashion sense, culinary skills, and smartphones, albeit with occasional password forgetfulness. However, we know that climate change will continue to occur, requiring many species to adapt to survive. Additionally, convergence, which occurs when unrelated organisms develop similar traits to succeed in specific environments, could play a crucial role.

For instance, fish have evolved to suit aquatic life with their torpedo-shaped bodies and fins, but dolphins have developed similar body shapes, even though they are warm-blooded, air-breathing mammals with a distinct evolutionary background. Perhaps some animals could evolve hands similar to ours and fill the same roles as humans, such as building cities and modifying the environment. Primates like chimpanzees and bonobos are already close to achieving this, with their opposable thumbs, which they use to create tools in the wild.

Furthermore, it's possible that birds, which are the only surviving dinosaurs, could become the new smartest animals if humans vanished. Birds are intelligent and can flock in large groups, and some, like sociable weavers, even build communal nests. Octopuses are likely the most intelligent non-human creatures on Earth, capable of distinguishing between real and virtual objects and engineering their environments. However, adapting to life on land could prove challenging for them.

There's still much to learn about animal intelligence, and humans have historically been arrogant about it. Previously, we believed that animal intelligence could be arranged into a hierarchy, with humans at the top and insects at the bottom. However, researchers in the 1960s challenged this notion, suggesting that intelligence should be evaluated in relative terms rather than absolutes. As technology improves, we can observe animals more frequently without disrupting them, and we're discovering that they're more intelligent than we previously thought.

For example, researchers in Melbourne use remote-controlled drones to monitor the breeding habits of southern right whales, and artificial intelligence aids in tracking and forecasting the movements of various creatures. Dolphins use names and even have accents, as evidenced by Brazilian dolphins' distinctive accent after interacting with local fishers for over a century. Parrots have complex social structures and can differentiate between members of their species based on their relationships. Insects, despite having tiny brains, can use tools and learn through observation.

We once believed that intelligence was exclusive to humans and some primates, but that's not the case. Intelligence is distributed differently throughout the animal kingdom, with each species excelling in different areas depending on their environmental pressures and adaptability. While we recognize the usual suspects for high intelligence in animals, such as chimps, dogs, and dolphins, there are unexpected additions to the list, like cats, who are excellent observers and learners, as demonstrated by Nora, a cat who learned to play the piano from her owner and became a sensation.

Finally, rats, typically considered pests, have been trained to detect lung disease in saliva samples in Africa, showcasing their impressive olfactory abilities. Thus, we shouldn't be arrogant about animal intelligence, and we must acknowledge the diverse ways that intelligence manifests in the animal kingdom