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Updated: Aug 17, 2026

Frequency and Distribution of Crossovers in Caenorhabditis elegans Meiosis by SNP Genotyping using Real-time PCR
Published on: July 11, 2025
Coexistence of competing species by the oscillation of polymorphisms
Satoshi Takahashi1, Michio Hori
1Department of Information and Computer Sciences, Nara Women's University, Kitauoyanishimachi, Nara 630-8506, Japan. takahasi@lisboa.ics.nara-wu.ac.jp
Abstract:
Scale-eating cichlids in Lake Tanganyika exhibit genetically determined lateral asymmetry, especially in their mouth-opening. Frequencies of the morphs oscillate due to strong frequency-dependent selection caused by the switching of prey's attention, and its delayed effect by their growth period. Two scale-eaters coexist in similar densities at south shore of the lake, with their morph frequencies oscillating in phase. We investigated the effect of the oscillation in morph frequencies to the coexistence of competing species. If the difference of two species' growth period is large, the oscillation facilitates the coexistence of the two species, while small difference of growth periods hinders their coexistence. In the latter case, the species with shorter growth period drives the other species to the extinction.
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