Honeybee Society

In a honeybee colony, the queen is the mother of essentially all the bees in the hive. She lays both fertilized and unfertilized eggs. Fertilized eggs develop into females—either workers or queens. Unfertilized eggs develop into males, called drones. The female workers do not necessarily have the same father. A queen mates with multiple drones, usually during mating flights early in her life. She stores the sperm from these males and later uses it to fertilize her eggs. As a result, all the workers have the same mother, but different groups of sisters can have different fathers. So a hive isn't simply one mother and thousands of identical daughters. It is more like a huge extended family: one queen mother, many daughters, and several paternal lineage, the workers themselves normally do not reproduce. Their role is to care for the queen's offspring, maintain the hive, collect food, and keep the colony alive.

Evolution

The remarkable part is natural selection could favor a system in which most females do not reproduce themselves. A worker spends her life helping her mother raise offspring instead of producing her own. Because she is closely related to the bees she helps raise, cooperation can still allow many of the same genes to be passed into future generations. This is part of the evolutionary explanation known as kin selection.

The unusual genetic system of honeybees may also have helped shape this social structure. Because females develop from fertilized eggs and males from unfertilized eggs, female bees can be especially closely related to one another under certain mating patterns. This can make helping sisters and other relatives an effective evolutionary strategy, creating conditions in which cooperation can be favored over individual reproduction.

Over many generations, small differences that improved the survival and reproductive success of cooperative colonies could become more common. The result is a society in which individuals specialize in different roles: reproduction is concentrated in a small number of females, while others devote themselves to maintaining the colony. What looks like self-sacrifice at the individual level can therefore make evolutionary sense at the level of shared genes and relatives.

Is This How All Bees Live?

The honeybee's highly organized society is not representative of all bees. Most bee species are actually solitary. A solitary female builds her own nest, collects food for her offspring, lays her eggs, and leaves the young to develop without a large workforce.

Honeybees belong to a group of animals with an extreme form of social organization called eusociality. In a eusocial society, individuals cooperate to raise offspring, generations overlap, and some members specialize in reproduction while others largely give up reproduction themselves. This kind of social organization has evolved in several different groups of animals, including ants, termites, and some bees and wasps.