Parasites on parasites: Coupled fluctuations in stacked contact processes
SUPA, School of Physics and Astronomy, University of Edinburgh - Mayfield Road, Edinburgh EH9 3JZ, UK
Received: 7 December 2012
Accepted: 12 February 2013
We present a model for host-parasite dynamics which incorporates both vertical and horizontal transmission as well as spatial structure. Our model consists of stacked contact processes (CP), where the dynamics of the host is a simple CP on a lattice while the dynamics of the parasite is a secondary CP which sits on top of the host-occupied sites. In the simplest case, where infection does not incur any cost, we uncover a novel effect: a non-monotonic dependence of parasite prevalence on host turnover. Inspired by natural examples of hyperparasitism, we extend our model to multiple levels of parasites and identify a transition between the maintenance of a finite and infinite number of levels, which we conjecture is connected to a roughening transition in models of surface growth.
PACS: 02.50.Ey – Stochastic processes / 05.70.Fh – Phase transitions: general studies / 87.23.Cc – Population dynamics and ecological pattern formation
© EPLA, 2013