Dresden 2009 – wissenschaftliches Programm
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BP: Fachverband Biologische Physik
BP 17: Poster II
BP 17.38: Poster
Mittwoch, 25. März 2009, 17:15–19:45, P3
Competition between sexual and asexual reproduction: geographic parthenogenesis in structured resource space — •Yixian Song1, Irene Ament3, Stefan Scheu2, and Barbara Drossel1 — 1Institut für Festkörperphysik, Technische Universität Darmstadt, Deutschland — 2Institut für Zoologie, Technische Universität Darmstadt, Deutschland — 3Institute for Physical Chemistry, Johannes Gutenberg Universität, Mainz, Deutschland
In spite of the twofold cost of sex due to the production of males about 95% of species are sexual. Since the paradox of sexuality was pointed out by Darwin(1859), many explanations were suggested, e.g. Muller’s ratchet(1964),Williams’ Lottery model(1975), Bell’s Tangled Bank(1982), and related models. The recently introduced Scheu-Drossel model(2007) is based on the fundamental fact of limited and structured resources. In this model asexual species win over sexual species only when mortality rates are large, resources regrow fast, many different genotypes are allowed to coexist at the same place, or when resource diversity is small. By adding spatial structure into this model, we obtained a pattern resembling geographic parthenogenesis. "Geographic parthenogenesis" describes the fact that many species reproduce asexually at the boundaries of ranges, i.e. in northern regions, at high elevations, or the transition to deserts. By including a gradient in the rate of mortality or resource diversity in our computer simulations a stable distribution was obtained, with sexuals prevailing in regions of low mortality and high resource diversity, while asexuals prevailing at the boundary, where mortality is high or resource diversity low.