Ever since we go to school, in the hours of science they teach us that a species is a group of organisms that reproduce together giving life to fertile offspring. However, there is, as told in a study on Naturean ant that challenges this convention and overturns what we know on the very idea of ”species”: its queens, in fact, lay eggs that, when they hatch, bring out a male of another species, belonging to the same genre but evolutively distant from the original one.
The phenomenon has already been baptized “xenoparity”, that is, literally giving birth to a “foreigner”.
How did they notice them? Let’s start from the beginning. The ant in question belongs to the species Mesor Ibericuswhich as the name suggests is present throughout Europe but in particular in the Iberian peninsula. Genre Mesor It is famous at those who study ants for the high hybridization rate between the different species, e M. Ibericus Bring this feature to its extreme. Observing the anthills, in fact, the team of the University of Montpellier who conducted the study discovered that about half of the males are covered by a thick hair, while the other half are peeled.
Identikit of the male. The team therefore decided to investigate the identity of these males, first discovering that, in this ant, they are much rarer than females: in total they have identified 132 in 26 different colonies, each of which are populated by about 10,000 individuals.
It was mainly the males without hair: it is in fact a typical feature of another kind of genre, M. Structor. And the genetic analysis of the specimens has shown that yes, peeled males belong to another species. Not only that: since the queens of M. Ibericus They can only produce males or other queens, all females of their anthills are hybrid between the two species.
A unique agreement in the world. In the practical act, this strangeness works like this: the queens of M. Ibericus mate with the males of M. Structorand keep the sperm. They then use it to fertilize some of their eggs, removing their genetic material from the nucleus so that, once born, the ant is a male of M. Structor without a trace of Ibericus. The eggs from which genetic material has not been removed instead give light hybrid females between the two species, which act as workers in the colony.
Evolutionaryly distant. One of the most curious details of this extraordinary affair is that the two species, although belonging to the same genre, are not as evidently close: their last common ancestor is more than five million years old (we humans separated from the chimpanzees six million years ago, to understand each other).
Moreover, M. Structor usually lives in the mountains, while Ibericus It occupies a great variety of different environments: in this way, the first species has spread even in environments that are not his. The only problem is that this tacit agreement may not last: since males are all clones that cannot mate with females of their species, it is possible that they are accumulating negative genetic mutations that could cause their long -term problems. For the moment, however, this strangeness works.