Core Characteristics of Eusocial Societies

Eusocial societies are defined by several key traits:

• Altruism: Many individuals, such as worker bees or ants, forego their own reproduction to help raise the offspring of a single or a few reproductive individuals (queens). This self-sacrifice is a hallmark of eusociality.

• Kin Selection: The evolution of eusociality is closely linked to kin selection, where individuals increase their genetic fitness by helping relatives reproduce.

• Guarding Against Intruders: Defensive behaviors, including guarding the colony and protecting brood from predators or rival colonies, are common in eusocial species.

• Reproductive Division of Labor: There is a clear separation between reproductive and non-reproductive castes. Usually, only the queen and a few males reproduce, while the majority of the colony (workers and soldiers) do not reproduce at all.

What Eusocial Societies Are NOT

A defining feature of eusociality is the lack of equal reproductive opportunities. In these societies, reproduction is highly skewed; only specific individuals (typically the queen and select males) are responsible for producing offspring, while the rest of the colony supports them through various non-reproductive roles. This reproductive inequality is essential for maintaining the structure and efficiency of the colony.

Equal reproductive opportunities are NOT a characteristic of eusocial societies.

Conclusion

While eusocial societies are characterized by altruism, kin selection, and cooperative defense, they are fundamentally defined by unequal reproductive roles. Most members never reproduce, dedicating their lives to supporting the reproductive elite—a system that has driven the extraordinary success of eusocial species.

Correct answer: (4) Equal reproductive opportunities