Most insects, especially social ones, are one for us - just like for their fellows. Only a few species have acquired in the process of evolution the skill of visually distinguishing one member of their family from another. According to the authors of the article, published in the Proceedings of the National Academy of Science, very rapid evolution shows that this intellectual superiority over related species gave the northern paper wasp Polistes fuscatus an evolutionary advantage.
One of the authors of the work, neuroscientist Michael Sheehan of Cornell University, notes that the most surprising thing is that selection during the evolution of the species did not follow the usual and usually taken into account directions: climatic changes, methods of catching prey or fighting enemies and parasites. The key factor is changes in communication within the swarm.
Scientists found the ability of these insects to use sight to identify "their" back in 2002. The "faces" of the wasps were painted, dividing them into two groups. In one group, this "make-up" changed the position of the colored elements inherent in them in a natural form, while in the second it repeated the usual coloring. It turned out that the attitude towards wasps from the first group in the hive, where they were returned, was aggressive - but only for the first time. Having figured out and recognized them as "theirs", the other wasps of the swarm after a short period of time remembered them and began to communicate as before.
Among insects, this is a rare ability, so scientists analyzed the genome of Polistes fuscatus, comparing it with the genome of related species Polistes metricus and Polistes dorsalis, in which they did not find such super skills.
They know each other by sight / © Live Science
It turned out that the changes that could cause such pronounced cognitive changes in P. fuscatus have occurred only in the last several thousand years, while in the other two species they have not.
Researchers have found in P. fuscatus relatively recent (in an evolutionary sense) strong, rigid selective scans, the loci of which can be explained by functions associated with long-term memory formation, the development of brain mushroom bodies, and visual processing. Since it was the cognitive loci that turned out to be selected in the first place, we can say that it was the evolution of cognitive abilities that was one of the strongest selection factors in the recent evolutionary history of these insects.
Some other insects with the same abilities, several species of bees and wasps known today, have not one queen in the hive, but several at once, and they have a hierarchy and fight for power. Probably, in such a struggle it is important to know the enemy by sight.
Scientists note that one of the trends in recent scientific works is the explanation of how cognitive evolution can be formed by natural selection. New research shows that these cognitive changes can happen very quickly. This is not necessarily a slow and gradual process: mutations can bring about large and rapid changes. “This suggests the possibility that rapid cognitive adaptation might be important in other species, just like language in humans,” Sheehan says.