Ants: a decentralized micro chemical factory
Event details
| Date | 08.05.2012 |
| Hour | 11:30 › 12:30 |
| Speaker | Jean-Louis Deneubourg, Université Libre de Bruxelles, Belgium |
| Location | |
| Category | Conferences - Seminars |
The organization of complex societies requires constant information flow between individuals. Food sharing is vital for a large number of species and is of particular importance within highly integrated societies, such as in colonial organisms and in social insects. There is no doubt that the shape of the food web organizes itself according to the spatial distribution of the individuals and of the stocks and that these stocks influence the spatial distribution of the insects. Nevertheless, the mechanisms and information exchange between individuals that govern the distribution of food inside a complex organizational system such as an ant colony remain largely unknown.
Incorporating division of labour and complex communication pathways, communities of social insects are a prime example of collective energy management. To identify the relations between food retrieval, the food exchange, the division of labour and the spatio-temporal organization of the food stock, an approach coupling theoretical modelling and experiments is followed.
To quantify how the spatial organization of the food stocks changes with the colony needs, we monitored the flow of radiolabeled sugar solution inside an ant nest at different degrees of starvation (sequential scintigraphy). The sugar is the major source of energy. The spatial dynamics of the food flow revealed stable patterns and fine-tuning regulation of the feeding process. At the scale of the colony, the collective regulatory stock management task can be reproduced by a simple model that integrates a positive and a negative feedback proportional to the number of ants that already received food.
Spatial analysis of the sugar distribution showed that energy is heterogeneously stocked among individuals and also heterogeneously consumed. Furthermore, a regular spatial structure emerges, leading to centralization of the stocks: heavily loaded individuals being at the center of the cluster and weakly loaded individuals at its periphery. Mathematical modelling suggests that this aggregation-segregation seems to result from a trade-off between the individual specialization and the inter attraction between individuals.
The centralization of both resources and information in self-organized systems might be a widespread phenomenon that deserves further studies.
Bio:
http://www.ulb.ac.be/sciences/use/deneubourg.html
Incorporating division of labour and complex communication pathways, communities of social insects are a prime example of collective energy management. To identify the relations between food retrieval, the food exchange, the division of labour and the spatio-temporal organization of the food stock, an approach coupling theoretical modelling and experiments is followed.
To quantify how the spatial organization of the food stocks changes with the colony needs, we monitored the flow of radiolabeled sugar solution inside an ant nest at different degrees of starvation (sequential scintigraphy). The sugar is the major source of energy. The spatial dynamics of the food flow revealed stable patterns and fine-tuning regulation of the feeding process. At the scale of the colony, the collective regulatory stock management task can be reproduced by a simple model that integrates a positive and a negative feedback proportional to the number of ants that already received food.
Spatial analysis of the sugar distribution showed that energy is heterogeneously stocked among individuals and also heterogeneously consumed. Furthermore, a regular spatial structure emerges, leading to centralization of the stocks: heavily loaded individuals being at the center of the cluster and weakly loaded individuals at its periphery. Mathematical modelling suggests that this aggregation-segregation seems to result from a trade-off between the individual specialization and the inter attraction between individuals.
The centralization of both resources and information in self-organized systems might be a widespread phenomenon that deserves further studies.
Bio:
http://www.ulb.ac.be/sciences/use/deneubourg.html
Links
Practical information
- General public
- Free
Organizer
- Alcherio Martinoli (DISAL)
Contact
- Massimo Mastrangeli (DISAL)