Monday, 27 August 2007 - 4:00 PM
1.P2.D-2
Molecular data can help to unveil biogeographic complexities since the Miocene: lessons from ameronothroid mites and isotomid springtails
Bettine Jansen van Vuuren1, Elizabeth Mortimer1, Mark I. Stevens2, David J. Marshall3, Peter Convey4, Savel R. Daniels1, and Steven L. Chown5. (1) Botany and Zoology, Stellenbosch University, Merrimen Street, Stellenbosch, South Africa, (2) Allan Wilson Centre for Molecular Ecology and Evolution, Massey University, Private Bag 11-222, Palmerston North, New Zealand, (3) Biology, University of Brunei, Jalan Tungu Link, Gadong BE 1410, Darussalam, Brunei, (4) Biological Sciences, British Antarctic Survey, High Cross, Madingley Road, Cambridge, CB3 0ET, United Kingdom, (5) DST-NRF Centre of Excellence for Invasion Biology, Stellenbosch University, Merrimen Street, Stellenbosch, South Africa
Summary
The diversification of Antarctic springtails and mites is likely to have occurred as a result of the glaciation and isolation of the Antarctic continent completed by ~10 mya, and not by the sequential break-up of Gondwana (completed by ~32 mya). More recently, population level structuring is likely to have been driven by the repeated glacial cycles of the Pleistocene (<2 mya) or common circum-polar corridors. It is clear that current taxonomic designations based on morphology for these springtails and mites are in conflict with our molecular topologies. These taxonomic inconsistencies are clear given the large number of paraphyletic species presented here. Our data show clear inconsistencies between the contemporary taxonomy and molecular evidence and we propose a full taxonomic revision for the ‘Cryptopygus’ group, the Halozetes genus, and indeed the larger ameronothroid group where detailed morphological investigations may help to resolve “unexpected” relationships when taking traditional classifications into account.
The diversification of Antarctic springtails and mites is likely to have occurred as a result of the glaciation and isolation of the Antarctic continent completed by ~10 mya, and not by the sequential break-up of Gondwana (completed by ~32 mya). More recently, population level structuring is likely to have been driven by the repeated glacial cycles of the Pleistocene (<2 mya) or common circum-polar corridors. It is clear that current taxonomic designations based on morphology for these springtails and mites are in conflict with our molecular topologies. These taxonomic inconsistencies are clear given the large number of paraphyletic species presented here. Our data show clear inconsistencies between the contemporary taxonomy and molecular evidence and we propose a full taxonomic revision for the ‘Cryptopygus’ group, the Halozetes genus, and indeed the larger ameronothroid group where detailed morphological investigations may help to resolve “unexpected” relationships when taking traditional classifications into account.