Like the Chavo del Ocho when he did for the umpteenth time the joke to continue criticizing Professor Jirafales once the others had silenced, nature can have somewhat repetitive scripts. The point is that they work.
Trend to eat ants and termites. It doesn’t matter if we are in America, Africa or Asia. Again and again, throughout the history of the earth, different mammalian lineages have reached the same evolutionary conclusion, developing a similar body plan to exploit one of the most abundant banquets on the planet.
A recent study Posted in Evolution magazine It reveals that the specialization in eating ants and termites (a feature known as Mirmecophage) has emerged independently at least 12 times different since the extinction of dinosaurs 66 million years ago.
Convergent evolution. When we think of an anthill, the iconic elongated snout animal of the Americas comes to mind. But the anthill is not alone. Pangolines and Aardvarks, who inhabit Africa and Asia, are distant relatives who have developed a surprisingly similar tools kit.
Adaptations include long and sticky tongues, a reduced or non -existent teeth and powerful front legs armed with claws to dig in insect nests. This phenomenon, in which unrelated species They develop similar features To adapt to similar conditions, it is known as convergent evolution.
The same strange design. “The specializations associated with Mirmecophage are among the strangest and most fascinating mammals,” says Laura Wilson, an evolutionary biologist, In Science magazine. “This study illuminates our understanding when, and how many times, these fascinating characteristics evolved and under what conditions.”
To reach these conclusions, the also biologist Thomas Vida and his team collected and analyzed data on the diet of almost 4,100 species of mammals, mapping their eating habits in the great evolutionary tree. The resulting model left no doubt: the evolution has taken the path of mirmecophagy over and over again, and has done so in the three large branches of mammals, including marsupials and monretrems, which put eggs.
The postdinosaurs world. There are several crustaceans that have evolved towards a body shape similar to that of a crab. This phenomenon has occurred at least five times, but over several hundred million years. Mirmecophagous mammals, on the other hand, have done it 12 times in just 66 million years. “For some reason, things continue to evolve until they become hormigueros,” says the author of the study.
Why this rise of ants dining rooms just after the disappearance of dinosaurs? The answer, according to researchers, is in the history of social insects. After the great extinction of the Cretaceous-Paleogen, the ants and the termites experienced a demographic explosion. His presence in the fossil registry shot, and his biomass became an abundant ecological resource.
A road without return. The study also reveals another fascinating fact: once a mammalian lineage specializes in eating ants and termites, it seems that there is no turning back. The researchers only found a reversal case: the musarañas elephant of short ears. Their ancestors were probably fed on ants and termites more than 13 million years ago, but today, these southern Africa creatures have a mixed diet that includes other insects and plant matter.
This evolutionary dead end is probably due to the stability and abundance of the food source, or the difficulty of recovering the features of a generalist once the body has adapted to such a specific diet. The story, therefore, tells us that while there are ants and termites in abundance, the evolution will continue to threaten more mammals into relentless devouring machines of colonies.
Image | Claudio Olivares Medina (CC BY-DC -nd 2.0)
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