Hanzi

Many people have this question: since dinosaurs ruled the Earth for 160 million years, why didn't they evolve into highly intelligent beings or even establish a civilization? Yet humans achieved this in just two million years. In fact, the improvement of animal intelligence is the combined result of environment, predatory relationships, and species competition. Highly intelligent humans are a product of evolutionary trends, rather than a pure coincidence.

In fact, it's not just humans who are evolving; almost all mammalian branches are becoming smarter. By comparing fossils, we find that modern felines, canines, orcas, and elephants all have larger brain capacities than similar species from tens of millions of years ago. Even today's birds are much smarter than their dinosaur ancestors. This indicates that throughout the evolutionary history of life on Earth, the ceiling of intelligence has been constantly rising.

We must clarify a fundamental fact: all life on Earth shares a common ancestor. This means that for as long as dinosaurs existed, the ancestors of humans were also living on Earth. Humans didn't just appear out of nowhere. If you trace human evolutionary history, you'll find that the ancestors of apes were certain primitive primates, and their ancestors can be traced back to the inconspicuous small mammals of the Mesozoic era.

During the era when dinosaurs ruled the Earth, human ancestors looked like modern shrews and were extremely small. For example, Juramaia sinensis, which lived in the Late Jurassic, weighed only 13 grams with a brain the size of a paperclip. You could hardly expect such a tiny creature to exhibit high intelligence at that time. In reality, during those long ages, the intelligence level of human ancestors did not experience a qualitative leap.

Interestingly, during the Mesozoic, the smartest animals on Earth were likely not mammals, but certain dinosaurs. Research shows that dinosaurs like Troodon and Microraptor had higher body temperatures, fast metabolisms, and feathers. Fossil evidence suggests they had relatively high brain-to-body ratios and exhibited social and cooperative hunting behaviors. Comparisons show that the intelligence of these clever dinosaurs might have been equivalent to some of today's birds, far exceeding mammals that hadn't yet developed complex brain structures.

Since dinosaurs weren't stupid, would they have had the chance to evolve high intelligence if they hadn't gone extinct? The answer is yes. Look at today's parrots and corvids, often called "feathered primates." Some parrots have more neurons than certain monkeys and display astonishing cognitive abilities. Birds are a branch of dinosaurs. If terrestrial maniraptorans hadn't gone extinct and weren't constrained in size for flight, they could very likely have evolved into a true "Dinosauroid" over tens of millions of years.

So why did humans ultimately succeed? There is a fascinating logic to this. The “neocortex” in mammalian brains, responsible for high-level cognitive abilities, actually emerged under the long-term suppression of dinosaurs. To evade dinosaurs, mammalian ancestors were forced to be nocturnal, leading to visual regression but greatly enhanced smell and hearing. It was this adaptation to nocturnal life that spurred the development of the early cerebral cortex. One could say that without the “pressure” from dinosaurs back then, the unique structure of the human brain might never have appeared.

In summary, evolution requires motivation, and pressure is the source of that motivation. Dinosaurs were not "idle" throughout those long ages; one of their branches—birds—still demonstrates high intellectual potential today. Humans stood out because of both long-term biological accumulation and the ecological space left behind after the dinosaur extinction. What dinosaurs lacked was not evolutionary potential, but rather a little bit of luck and extra time.