Since the non-avian dinosaurs went extinct 66 million years ago, mammals have independently evolved on at least 12 occasions, based on ants andtermiteA specialized form of food. This discovery, published in the journal Evolution by a research team from the University of Bonn in Germany, reveals the profound impact of social insects on the evolution of mammals.
In the rainforests of Central and South America, the combined weight of ants and termites exceeds that of all other insects, mammals, amphibians and birds combined; globally, the total weight of termites is even 10 times that of wild mammals. This massive biomass prompted mammals to repeatedly evolve ant-eating adaptations, such as long, sticky tongues, vestigial teeth, and strong forelimbs. By analyzing the dietary data of nearly 4,100 species of mammals, the research team found that antivores appeared many times after the end of the Cretaceous, and spanned three major groups of mammals, including marsupials and oviparous monotremes.
This phenomenon is called convergent evolution, similar to how crustaceans independently evolved crab-like body structures multiple times. But the evolution speed of mammalian antivory is even more alarming - the "crabification" of crustaceans spanned hundreds of millions of years and evolved independently only 5 times, while mammalian antivory evolved independently at least 12 times in 66 million years. The study also found that ant-eating is an almost irreversible evolutionary path, and only one type of mammal, the short-eared elephant shrew, has been found to have given up this eating habit.
The rise of anteater evolution is linked to the explosion of ants and termites that followed the extinction of the dinosaurs. Their proportion surged from 1% to 45%, possibly related to the expansion of flowering plants. At the same time, termites evolved large nest colonies, providing a stable food source for anteaters.
This trend may also have influenced the evolution of social insects. Faced with pressure from mammalian predators, ants and termites may develop larger colony sizes or stronger defense mechanisms. Research shows that evolution continues to push mammals toward ant-eating species, which means that ants and termites will face long-term survival challenges.