Open AccessSimulation modeling reveals the evolutionary role of landscape shape and species dispersal on genetic variation within a metapopulation
Author(s) -
Chiu MingChih,
Nukazawa Kei,
Carvajal Thaddeus,
Resh Vincent H.,
Li Bin,
Watanabe Kozo
Publication year - 2020
Publication title -
ecography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.973
H-Index - 128
eISSN - 1600-0587
pISSN - 0906-7590
DOI - 10.1111/ecog.05118
Subject(s) - metapopulation , biological dispersal , ecology , biology , genetic divergence , genetic structure , sympatric speciation , habitat , spatial ecology , watershed , evolutionary biology , genetic variation , genetic diversity , population , biochemistry , demography , machine learning , sociology , gene , computer science
Different shapes of landscape boundaries can affect the habitat networks within them and consequently the spatial genetic‐patterns of a metapopulation. In this study, we used a mechanistic framework to evaluate the effects of landscape shape, through watershed elongation, on genetic divergence among populations at the metapopulation scale. Empirical genetic data from four, sympatric stream‐macroinvertebrates having aerial adults were collected from streams in Japan to determine the roles of species‐specific dispersal strategies on metapopulation genetics. Simulation results indicated that watershed elongation allows the formation of river networks with fewer branches and larger topographic constraints. This results in decreased interpopulation connectivity but a lower level of spatial isolation of distal populations (e.g. those found in headwaters) occurring in the landscapes examined. Distal populations had higher genetic divergence when their downstream‐biased dispersal (relative to upstream‐ and/or overland‐biased dispersal) was high. This underscores the importance of distal populations influencing genetic divergence at the metapopulation scale for species having downstream‐biased dispersal. In turn, lower genetic divergence was observed under watershed elongation when the genetic isolation of distal populations was decreased in such species. This strong association between landscape shape and evolutionary processes highlights the importance of natural, spatial architecture in assessing the effectiveness of conservation and management strategies.