An Organismal Perspective on the Evolution of Insect Societies

Heikki Helanterä

doi:10.3389/fevo.2016.00006

Abstract

Insect societies, i.e. the colonies of eusocial ants, bees, wasps and termites, have been likened to multicellular organisms for more than a century. This framework of “superorganisms” has to date largely been used as a mechanistic description of colony functioning, or as an example of an evolutionary transition in individuality. Here I take the superorganismal view a step further, and explore what can potentially be gained if we truly accept insect societies as organisms. I suggest ways to test evolutionary theories about organismal features originally derived for solitary organisms using traits of insect societies as analogies. I explore examples such as evolution of anisogamy, sex allocation and fertilization strategies and life histories, and point out promising directions for comparative work, and potential confounding factors in such analyses, derived from social insect studies.

Highlights

Ants, termites and many bees and wasps live in colonies with reproductive division of labor between the reproductive queen(s) and the largely sterile workers
The above can be viewed from several different viewpoints. It offers us a potential complementary conceptualization of the evolution of insect societies, a window into understanding diversity of social insect life histories and reproductive strategies in a new light, e.g., when male and queen sizes and sex allocation are interpreted in the light of gamete competition theories
It highlights testing grounds for broad comparative predictions across levels of organismality, e.g., when shared life history trade-offs are analyzed in solitary organisms and superorganisms

Summary

Introduction

Termites and many bees and wasps live in colonies with reproductive division of labor between the reproductive queen(s) and the largely sterile workers. In addition to queen-worker conflict as an explanation of sex ratios, the extent of within-sex competition over either mates or resources may explain considerable parts of the variation within species (Meunier et al, 2008), but such patterns are consistent with either view—i.e., can be explained through theories that take a perspective of either the organism and its gametes, and the sizes of local mating groups where the gametes compete, or numbers of males and females produced and their competition.

Results

Conclusion