Details of Award
NERC Reference : NE/C511264/1
Conflict resolution in mutualisms.
Grant Award
- Principal Investigator:
- Professor J Cook, Imperial College London, Biological Sciences
- Co-Investigator:
- Professor DW Yu, University of East Anglia, Biological Sciences
- Grant held at:
- Imperial College London, Biological Sciences
- Science Area:
- Terrestrial
- Overall Classification:
- Terrestrial
- ENRIs:
- Biodiversity
- Science Topics:
- Population Genetics/Evolution
- Population Ecology
- Behavioural Ecology
- Abstract:
- Many organisms are involved in intimate associations with other species. In general the smaller partner (symbiont) lives partly in or on the larger partner (host). Symbioses can be beneficial to both partners, in which case they are called mutualisms, or can involve one partner (the parasite) inflicting harm on the other (host). Even when both partners appear to gain from the association, they do not always have the same evolutionary interests. There is no hard and fast border between parasitism and mutualism and it is important to understand what factors favour positive or negative effects of the symbiont on the host. This is especially so if the symbiont is only parasitic under certain circumstances, as in many microbial infections of animals. More generally, mutualism is of immense importance in biology, both in the short and long term. For example, their association with rhizobial bacteria allows bean plants access to nitrogen. Mutualism can also lead to major evolutionary events and the two major genetic components of our cells (nucleus and mitochondria) had their origins in an ancient mutualism. Despite the importance of mutualism, there is no general theory that explains when we should expect a mutualistic outcome, or how the mutualists resolve their conflicts. However, there is increasing evidence that hosts can limit the parasitic tendencies of symbionts by controlling their access to key host resources and also influencing the way in which different individual symbionts have to compete with each other for access to host resources. This type of explanation could be applicable in a wide variety of cases including plants and pollinators, plants and nitrogen-fixing bacteria, and even some human diseases. This project will investigate how hosts control their symbionts using a model system involving fig trees and their pollinating wasps. This is a mutualistic interaction, but one with clear conflicts. Specifically, while figs need wasps to pollinate their flowers, the wasp larvae eat some of the fig seeds. The fig needs to manage the wasps so that they do not lay eggs in all the seeds. Figs may manage wasps by altering the quality and architecture of the fig flowers so that some are more desirable sites for wasp to lay eggs. This may be because some flowers are better places for wasp larvae to develop, or because some flowers are easier for wasps to lay eggs into, or both. In theory, the wasps' preference for certain flowers, plus the fact that they waste time rejecting flowers that they deem unsuitable, or flowers in which other wasps have laid eggs (only one egg can develop per flower), can prevent the wasps from exploiting too many of the seeds and allow the mutualism to persist. We will test this idea by making detailed studies of five pairs of figs and their pollinators, choosing the species to reflect the great differences in biology seen across the over 750 species of figs in the world. We will video and analyse the flower searching and egg-laying behaviour of wasps and also assess whether certain flowers give rise to better (bigger) wasp offspring. We will use the data to test the theoretical model for each species. We will also estimate just how much conflict there is between the fig and wasp partners in each case, by measuring the average number of wasps entering a fig, the average number of eggs per wasp, and the average number of flowers that these eggs could potentially exploit. In addition, we will investigate whether some fig species use extra mechanisms (such as rapid flower wilting) beyond those mentioned above to stop wasps laying too many eggs. Overall, the project will be a detailed investigation of how diverse fig species stop their pollinators from destroying all their seeds (thus allowing the mutualism to persist), using a new approach that should help us to understand not only these, but perhaps most mutualisms.
- NERC Reference:
- NE/C511264/1
- Grant Stage:
- Completed
- Scheme:
- Standard Grants Pre FEC
- Grant Status:
- Closed
- Programme:
- Standard Grant
This grant award has a total value of £154,021
FDAB - Financial Details (Award breakdown by headings)
| Total - T&S | Total - Staff | Total - Other Costs | Total - Indirect Costs |
|---|---|---|---|
| £16,603 | £70,216 | £34,903 | £32,299 |
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