Open AccessEvidence for nonallopatric speciation among closely related sympatric H eliotropium species in the A tacama D esert
Author(s) -
Luebert Federico,
Jacobs Pit,
Hilger Hartmut H.,
Muller Ludo A. H.
Publication year - 2014
Publication title -
ecology and evolution
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.17
H-Index - 63
ISSN - 2045-7758
DOI - 10.1002/ece3.929
Subject(s) - sympatric speciation , allopatric speciation , biology , evolutionary biology , genetic algorithm , sympatry , genetic divergence , incipient speciation , population , genetic structure , genetic variation , ecology , genetic diversity , genetics , gene flow , gene , demography , sociology
The genetic structure of populations of closely related, sympatric species may hold the signature of the geographical mode of the speciation process. In fully allopatric speciation, it is expected that genetic differentiation between species is homogeneously distributed across the genome. In nonallopatric speciation, the genomes may remain undifferentiated to a large extent. In this article, we analyzed the genetic structure of five sympatric species from the plant genus H eliotropium in the A tacama D esert. We used a mplified f ragment l ength p olymorphisms ( AFLP s) to characterize the genetic structure of these species and evaluate their genetic differentiation as well as the number of loci subject to positive selection using d ivergence o utlier a nalysis ( DOA ). The five species form distinguishable groups in the genetic space, with zones of overlap, indicating that they are possibly not completely isolated. Among‐species differentiation accounts for 35% of the total genetic differentiation ( F ST = 0.35), and F ST between species pairs is positively correlated with phylogenetic distance. DOA suggests that few loci are subject to positive selection, which is in line with a scenario of nonallopatric speciation. These results support the idea that sympatric species of H eliotropium sect. C ochranea are under an ongoing speciation process, characterized by a fluctuation of population ranges in response to pulses of arid and humid periods during Q uaternary times.