Computer Simulations to Study Sympatric Speciation Processes

K. Luz-Burgoa

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Computer Simulations to Study Sympatric Speciation Processes

K. Luz-Burgoa

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Abstract

We perform simulations based on the Penna model for biological ageing, now with the purpose of studying sympatric speciation, that is, the division of a single species into two or more populations, reproductively isolated, but without any physical barrier separating them. For that we introduce a new kind of competition among the individuals, using a modified Verhulst factor. The new competition depends on some specific phenotypic characteristic of each individual, which is represented by a pair of bitstrings. These strings are read in parallel and have no age structure. In this way, each individual genome consists of two parts. The first one has an age-structure and is related to the appearance of inherited diseases; the second part is not structured and takes into account the competition for the available resources. We also introduce sexual selection into the model, making use of another non-structured and independent pair of bitstrings. In this thesis we present three different models; two of them use, besides the competition, a sudden change in the ecology to obtain speciation. They were motivated by the speciation process observed in the Darwin finches, a family of birds that inhabits the Galapagos Islands, and also by that observed in the cichlids, a family of fish that lives in the Nicaragua Lakes and in the Vitoria Lake, in Africa. The third model does not use any ecological change: sympatric speciation is obtained depending only on the strength of competition among individuals with similar phenotypic characteristics.

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K. Luz-Burgoa. 2005-04-05. Computer Simulations to Study Sympatric Speciation Processes. https://arxiv.org/abs/q-bio/0504006

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