Scientists via a new study have attempted to trace the origins of social parasitism in ants to prove that not all ants are hardworking and their evolution might have been a shortcut. Published in the peer-review journal Proceedings of the National Academy of Sciences of the United States of America, the study suggests that the ants that opted for parasitism must have exploited the communal networks that already existed either in their own species or a closely related one instead of creating one of their own.
As per the study, the ruthless life strategies among ants has evolved at least 60 times, including some 400 socially parasitic species, revealed a report by Science Alert. This number is the highest recorded one when compared to the same strategies adopted by insects, fish, birds, and mammals, including humans.
In the study, the researchers have divided the social parasitism of ants into three classes, all of which evolved at different points in time. For studying the three classes, the scientists reconstructed the evolutionary history of Formica ants. These ants reportedly are the perfect candidates as they're the most social parasitic species of any ant genus.
The study suggested that ‘temporary social parasitism’ occurs when an ant queen loses its ability to breed new colonies, which tempts the ant to invade another's nest. The ant then ensures its survival by turning to parasitism, which involves killing the other queen and raising the latter’s offspring as its own.
As per the study, the common ant ancestor for temporary social parasites lived roughly 16 million years ago and evolved from multiple Formica species.
This class of parasitism has the same path of beginning as the first one, says the study. Here, an ant queen of one colony invades and kills the queen of another colony and captures the worker ants.
This process follows several ant nests, and the parasites proceed by either feeding on the young ones of a captured nest or raising them as their own offspring. The second class of parasites originated over two million years after the first one, reported Live Science.
Over the years, scientists have suggested that this approach is to either gather food, improve brood numbers, acquire territory or reduce nearby competition.
This class of parasitism is considered extremely rare and odd as two queens of different colonies live together without any hostility. Here the parasite queen is responsible for reproduction while the host queen produces her social network of workers. According to the study, this class of parasitic ants separated from temporary social parasites 12 million years ago and is reportedly the youngest of all parasites.