Date: February 17, 2017
Source: Okinawa Institute of Science and Technology (OIST) Graduate University
Social insects, such as ants, bees and wasps, display an organizational complexity, called eusociality, where individual members of a colony act more like parts of a whole rather than independent organisms. In their colonies, each individual performs specific tasks based on which caste they belong to: either the reproductive caste or the worker caste. In many species, the reproductive role is determined in early development -- by the time they are adults, queens and workers have set roles, complete with distinct appearances and functions. Remarkably, although ants, bees and wasps all evolved eusociality separately, all of their societies display this caste distinction. This begs the question: in these different organisms, have the same, or similar, genes evolved to differentiate social castes?
One way to answer this question is to look at exceptions to the general rule. In many ant species, queen ants are much larger than their worker counterparts. However, in some species, such as the native Okinawan Diacamma species, there are few differences in appearance between the worker caste and reproductive caste. These species are called "queenless ants" as a result, though a social hierarchy that includes both reproductive and worker castes exists within their colonies.