In an ant colony, different workers have physical differences from each other despite them all having the same parents. What determines the difference in the workers?
In: Biology
It’s complicated – different species have different castes, and achieve these castes through a variety of mechanisms, both genetic and environmental. However, there seems to be a common thread across these factors: size. Ant castes always have quite distinct sizes, with workers being the smallest and queens being the biggest, with soldiers and sub-queens somewhere in the middle. Castes appear to gain and lose features based on their size, and the middle-sized castes have features that are somewhere between those of a worker and a queen (for example, middle-sized castes often have better eyes than workers but worse eyes than queens).
What this means is that it appears ants have evolved mechanisms that link their physiology to their size, so that by modifying the size of the larvae, the traits of a particular adult caste are automatically created. Want to make a worker? Just keep the larvae small. Want to make a soldier? Make it bigger. Want to make a queen? Fertilise the egg and make it even bigger. Size regulation itself is a matter of complicated environmental and genetic interplay, such as availability of food, temperature level and presence of growth hormones, as well as deliberate actions by other ants to modify the ratio of workers, soldiers and queens produced – for example, in some species queens will inject eggs with certain hormones that reduce size, to prevent other queens appearing, if the number of queens is already high enough.
Latest Answers