2 results
22 - On optimal decision making in brains and social insect colonies
- from Part III - Action selection in social contexts
- Edited by Anil K. Seth, University of Sussex, Tony J. Prescott, University of Sheffield, Joanna J. Bryson, University of Bath
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- Book:
- Modelling Natural Action Selection
- Published online:
- 05 November 2011
- Print publication:
- 10 November 2011, pp 500-522
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Summary
Summary
The problem of how to compromise between speed and accuracy in decision making faces organisms at many levels of biological complexity. Striking parallels are evident between decision making in primate brains and collective decision making in social insect colonies: in both systems separate populations accumulate evidence for alternative choices, when one population reaches a threshold a decision is made for the corresponding alternative, and this threshold may be varied to compromise between the speed and accuracy of decision making. In primate decision making simple models of these processes have been shown, under certain parameterisations, to implement the statistically optimal procedure that minimises decision time for any given error rate. In this chapter, we adapt these same analysis techniques and apply them to new models of collective decision making in social insect colonies. We show that social insect colonies may also be able to achieve statistically optimal collective decision making in a very similar way to primate brains, via direct competition between evidence-accumulating populations. This optimality result makes testable predictions for how collective decision making in social insects should be organised. Our approach also represents the first attempt to identify a common theoretical framework for the study of decision making in diverse biological systems.
Introduction
Animals constantly make decisions. Habitat selection, mate selection, and foraging require investigation of, and choice between, alternatives that may determine an animal's reproductive success. For example, many animals invest considerable time and energy in finding a safe home (Franks et al., 2002; Hansell, 1984; Hazlett, 1981; Seeley, 1982). Similarly an animal may frequently have to deal with ambiguous sensory information in deciding whether a predator is present or not (Trimmer et al., 2008).
3 - Habitats
- Edited by Dave Checkley, Scripps Institution of Oceanography, University of California, San Diego, Jürgen Alheit, Yoshioki Oozeki, Claude Roy
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- Book:
- Climate Change and Small Pelagic Fish
- Published online:
- 08 January 2010
- Print publication:
- 20 August 2009, pp 12-44
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Summary
Summary
The habitats of populations of small, pelagic fish, especially anchovy and sardine, in the Benguela, California, Humboldt, and Kuroshio-Oyashio current systems, and in the NE Atlantic, are described and discussed in regard to future climate change. These stocks have been the primary concern of the Small Pelagic Fish and Climate Change (SPACC) program of International GLOBEC. Each of these regions and stocks has a unique set of climate and ocean conditions and their variability. However, they also share common characteristics. Spawning and development occurs within broad ranges of temperature (12–26 °C) and salinity (<30–36) and in regions of high plankton production, associated with either upwelling or freshwater. Often, sardine are more oceanic and anchovy more coastal, often associated with wind-driven upwelling and rivers. Sardine tend to make longer migrations between spawning and feeding regions than do anchovy. The habitat of most populations of small, pelagic fish expands when the population size is large and contracts when it is small, often into refugia. Climate change may affect populations of small, pelagic fish by causing poleward shifts in distribution due to warming, some of which have already occurred. Other potential effects are due to changes in winds, hydrology, currents, stratification, acidification, and phenology.
Introduction
Small, pelagic fish, especially anchovy and sardine, abound in many, productive regions of the world ocean. Their habitats include areas with coastal and oceanic upwelling and freshwater influence and can be characterized by both geography (properties of the coast and bottom) and hydrography (properties of the water). The effects of climate change, be it of natural or anthropogenic origin, on populations of small, pelagic fish, are mediated by their habitats.