Open AccessHigh levels of intraspecific genetic divergences revealed for Antarctic springtails: evidence for small‐scale isolation during Pleistocene glaciation
Author(s) -
Bennett Kristi R.,
Hogg Ian D.,
Adams Byron J.,
Hebert Paul D. N.
Publication year - 2016
Publication title -
biological journal of the linnean society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.906
H-Index - 112
eISSN - 1095-8312
pISSN - 0024-4066
DOI - 10.1111/bij.12796
Subject(s) - biology , ecology , glacial period , genetic divergence , molecular clock , range (aeronautics) , genetic diversity , genetic variability , intraspecific competition , population , springtail , glacier , phylogenetics , paleontology , biochemistry , demography , materials science , ecotoxicology , sociology , gene , genotype , composite material
We examined levels of genetic variability within and among populations of three Antarctic springtail species (Arthropoda: Collembola) and tested the hypothesis that genetic divergences occur among glacially‐isolated habitats. The study was conducted in southern Victoria Land, Ross Dependency, Antarctica, and samples were collected from locations in the vicinity of the Mackay Glacier. We analyzed mt DNA ( cytochrome c oxidase subunit I; COI ) sequence variability for 97 individuals representing three species ( Gomphiocephalus hodgsoni , N = 67; Cryptopygus nivicolus , N = 20; and Antarcticinella monoculata , N = 8). Haplotype diversity and genetic divergences were calculated and used to indicate population variability and also to infer divergence times of isolated populations using molecular clock estimates. Two of the three species showed high levels of genetic divergence. Gomphiocephalus hodgsoni , a widespread and common species, showed 7.6% sequence divergence on opposite sides of the Mackay Glacier. The more range restricted C. nivicolus showed 4.0% divergence among populations. The third species, A. monoculata , was found in only one location. Molecular clock estimates based on sequence divergences suggest that populations separated within the last 4 Mya. We conclude that habitat fragmentation resulting from Pliocene (5 Mya) and Pleistocene (2 Mya to 10 Kya) glaciations has promoted and maintained high levels of diversity among isolated springtail populations on relatively small spatial scales. The region surrounding the Mackay Glacier is likely to have provided refugia for springtail populations during glacial maxima and remains an area of high genetic and species diversity for Collembola within the Ross Sea region.