WaspCLIM · A continental-scale test of the climate hypothesis for the evolution of altruism in insects

A continental-scale test of the climate hypothesis for the evolution of altruism in insects

1. What is the problem being addressed? The living world is ruthlessly competitive, so why does cooperation evolve between animals? Untangling this enigma is among the great questions of biology. Recently, the debate has focused on the roles played by climatic variation. Does cooperation evolve in different climates in different ways and for different reasons? If we can identify the links between climate and cooperation, we may significantly advance our understanding of the evolution of animal behaviour. Answering this question requires a careful choice of study species. First, it must straddle a wide range of climates. Second, it must be experimentally tractable. Third, it should be a generalisable model for the evolution of cooperation. Working in Cameroon and South Africa, this MSCA fellowship focused on a strong system: the social wasp Belonogaster juncea. These wasps live across most of sub-Saharan Africa, from tropical rainforests to arid savannah, offering a window into social evolution under different climatic regimes. They live strikingly different lives under different climates: at temperate latitudes, for instance, they must hibernate for several months each year, with major knock-on effects for the cycle of cooperative nest building; in the tropics, by contrast, they do not hibernate. Moreover, they are regarded as living models for early stages in the evolution of 'eusociality'. 2. Why is it important for society? Social evolution deals with some of the most fundamental questions about the living world. Cooperation created the world around us - from the rise of the first genomes, cells, and multicellular organisms to our own species' journey from the savanna to complex societies of millions. Relating cooperation to climate is a central objective in the field, because it promises to shed light on the environmental factors that drive social evolution. Additionally, understanding the ecology, behaviour, and biodiversity of the social insects - the 'little things that run the world' - is an urgent objective in a time of global environmental change. Africa's Belonogaster wasps stretch across most of the continent, and likely play key roles as generalist predators. Moreover, they have recently started to receive attention as potential allies in the fight against invasive crop pests in subsistence farming. A prerequisite, however, is understanding how these animals live - the aim of this project. Finally, this fellowship has conducted outreach in four countries (the UK, US, South Africa, and Cameroon), aimed at sharing the excitement and wonder of biodiversity with diverse communities. 3. What are the overall objectives? The overall objectives of WaspClim are to contribute to a new understanding of the links between climate and cooperation, conduct outreach to the wider public, and develop Belonogaster wasps as a powerful study system for exploring social evolution over climatic gradients.

Data: CORDIS, © European Union