Genetic differentiation in environmental space: a study with two closely related species of lizards

CABAÑA JUAN IMANOL; RIVERA PAULA C.; CHIARAVIGLIO MARGARITA; DI COLA VALERIA; GUISAN ANTOINE

Berna

Congreso; Biology17: Annual Swiss Conference on Ecology, Evolution, Systematics and Conservation; 2017

Biology17: Annual Swiss Conference on Ecology, Evolution, Systematics and Conservation

The interactions between organisms and their landscape can shape the distribution of spatial genetic variability, resulting in different patterns.Isolation by distance (IBD) occurs when the level of gene flow is influencedby the geographical distances among populations. However, the environment also can affect the spatial distribution of the genetic variation, resulting in patterns of isolation by environment (IBE), independently of the geographic distance. We study two lizard species at local scale through an environmental cline in the Chaco region of Argentina. Salvator merianae and Salvator rufescens inhabit in different environments but overlap in a narrow ecotone area. We use a highly variable mitochondrial marker to calculate pairwise genetic FST distancesbetween population (FSTP) and between individuals (FSTI) and we performed mantel and partial mantel tests looking for patterns of IBD and IBE. Both species shown genetic differences along the study area, indicating low levels of gene flow. We found IBD in S. merianae using FSTI and FSTP and IBE pattern using FSTI but no FSTP. Salvator rufescens did not show pattern of IBD nor IBE with both genetic matrixes (FSTP and FSTI). At local scale, the use of FSTP (commonly used) instead FSTI can mask the effect of environment, because FSTP averages genetic distances among the individuals.