Question

Given the predicted relatedness of brothers, sisters, mothers, and fathers in a haplodiploid system, under Hamilton’s rule…

a. who should female worker bees favor when provisioning larvae? Is this in conflict with or not with what the queen should prefer? How and why?

b. What if the queen mated with more than one male (rather than a single male)? How would this change the dynamics of the hive?

Answer 1

Introduction: Kin selection is an approach in evolution. This selection favors the success in reproduction of an organism for its own survival and reproduction. Honey bees are haplodiploid organisms where females have two chromosome sets whereas males have a single chromosome set. Hamilton’s hypothesis suggests that in haplodiploid organisms the asymmetry in relatedness between haplodiploid females and lineages is because of true sociality and kin selection. Honey bees are major pollinators used commonly in agriculture. The bee colony has a fertile queen, drone bees which are haploid fertile males, worker bees which are sterile males formed from unfertilized eggs and nurse bees which are female loyal bees.

Explanation:

The self sacrificing behaviour in eusocial insects such as bees, termites and wasps is a common insight of Hamilton's rule. Honey bees are haplodiploid organisms where females are diploid and males are haploid.

a) Female worker bees favor when provisioning larvae

In a bee hive, the fertilized eggs develop into larvae that are totipotent in nature. The larvae are fed large quantities of nutrient-rich royal jelly to become queens whereas those that are fed with broods become workers. The queen bees are taken special care by loyal worker bees and providing her with emergency queen rearing to raise queens in urgency by feeding them with special food known as royal jelly. This is because the queen is the only member capable of laying fertilized eggs that can develop into females. She is larger than other worker females. She has a longer life span than the members of the colony. This is an extreme inequality or kinship followed in honey bees and is known as ‘voluntary altruism’ where workers are forced to work by policing.

b) Change in dynamics of hive due to polyandry

Polyandry is a process of multiple mating where one female mates with different male partners. In honey bees, the queen bee is inseminated with multiple males by the natural mating process which occurs in the congregation area. Thus the offspring has multiple fathers with different genetic origin from different hives. The polyandry helps in dynamics of the bee hive wherein, there is a genetic variation in the bee hive within a colony of honey bees. Polyandry reduces the average intra-colonial worker relation. The hive colony performance increases. It also increases tolerance to several environmental conditions within a colony of the hive. Also polyandry reduces the risk of formation of non-viable male bees in the bee colony.