Computer simulations on the sympatric speciation modes for the Midas cichlid species complex

TL;DR

This paper uses computer simulations to explore how sympatric speciation occurs in Midas cichlids, examining ecological, mating, and genetic factors that lead to species divergence with or without natural selection.

Contribution

It introduces a simulation model that investigates the conditions necessary for sympatric speciation in cichlids, highlighting different scenarios with and without disruptive natural selection.

Findings

Two speciation scenarios identified: with and without disruptive natural selection.

Ecological and genetic conditions can produce new species without natural selection.

Mating and genetic conditions must be synchronized to control genetic drift.

Abstract

Cichlid fishes are one of the best model system for the study of evolution of the species. Inspired by them, in this paper we simulated the splitting of a single species into two separate ones via random mutations, with both populations living together in sympatry, sharing the same habitat. We study the ecological, mating and genetic conditions needed to reproduce the polychromatism and polymorphism of three species of the Midas Cichlid species complex. Our results show two scenarios for the A. Citrinellus speciation process, one with and the other without disruptive natural selection. In the first scenario, the ecological and genetic conditions are sufficient to create two new species, while in the second the mating and genetic conditions must be synchronized in order to control the velocity of genetic drift.