M.Phil. Thesis, 30-09-2014: "
The Evolution of Signals and Amplifiers".
During my Master's programme at the
University of Cambridge, in the UK, I wrote my Master's Thesis in Zoology on a type of animal communication. In particular, I modelled the evolution of 'amplifiers'. This research paper was supervised by
Prof. Dr. Rufus Johnstone. In nature, information is often transferred between animals via displays. An amplifier is a display which reduces errors in perception of other characteristics for which there is direct selection. I found that, via its benefit to high quality animals, the amplifier can evolve to fixation and that direct choice for the amplifier can emerge if the amplifier is observable. Consequently, low quality animals may be seen to make use of the display as well, even though it amplifies their lower quality. I used both evolutionary game theory and signal detection theory to model this behaviour. I also extended signal detection theory to two dimensions and used this model to analyse handicap signalling in a novel manner. I found that the signalling equilibrium was more stable when animals relied on multiple displays.
Abstract: In 1989, Hasson published an article which introduced the concept of an amplifier within animal communication. This display would reduce errors in perception of other characteristics for which there was direct selection. Via its benefit to high quality animals, the amplifier can evolve to fixation and it was suggested that direct choice for the amplifier could emerge. This thesis models the evolution of amplifiers, showing that, if the use of an amplifying display is observable, direct choice will indeed evolve. Consequently, low quality animals may be seen to make use of the display as well, even though it amplifies their lower quality. The two modelling frameworks used in this thesis, evolutionary game theory and signal detection theory, also show how amplifiers can lead to preferences for other types of displays, such as handicap signals, and are used to model the dynamics of such displays. Finally, a simple experiment is conducted to test whether a specific pattern functions as an amplifier.
Related work:
Amplifiers and the Origin of Animal Signals
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