de Dinechin M., Ottvall R., Quillfeldt P. & Jouventin P. (2009). Speciation chronology of rockhopper penguins inferred from molecular, geological and palaeoceanographic data. J. Biogeogr., 36(4), 693–702.
Abstract: Aim The Southern Ocean is split into several biogeographical provinces between convergence zones that separate watermasses of different temperatures. Recent molecular phylogenies have uncovered a strong phylogeographic structure among rockhopper penguin populations, Eudyptes chrysocome sensu lato, from different biogeographical provinces. These studies suggested a reclassification as three species in two major clades, corresponding, respectively, to warm, subtropical and cold sub-Antarctic watermasses rather than to geographic proximity. Such a phylogeographic pattern, also observed in plants, invertebrates and fishes of the Southern Ocean, suggests that past changes in the positions of watermasses may have affected the evolutionary history of penguins. We calculated divergence times among various rockhopper penguin clades and calibrated these data with palaeomagmatic and palaeoceanographic events to generate a speciation chronology in rockhopper penguins.Location Southern Ocean.Methods Divergence times between populations were calculated using five distinct mitochondrial DNA loci, and assuming a molecular clock model as implemented in mdiv. The molecular evolution rate of rockhopper penguins was calibrated using the radiochronological age of St Paul Island and Amsterdam Island in the southern Indian Ocean. Separations within other clades were correlated with palaeoceanographic data using this calibrated rate.Results The split between the Atlantic and Indian populations of rockhopper penguins was dated as 0.25 Ma, using the date of emergence of St Paul and Amsterdam islands, and the divergence between sub-Antarctic and subtropical rockhopper penguins was dated as c. 0.9 Ma (i.e. during the mid-Pleistocene transition, a major change in the Earth's climate cycles).Main conclusions The mid-Pleistocene transition is known to have caused a major southward shift in watermasses in the Southern Ocean, thus changing the environment around the northernmost rockhopper penguin breeding sites. This ecological isolation of northernmost populations may have caused vicariant speciation, splitting the species into two major clades. After the emergence of St Paul and Amsterdam islands in the subtropical Indian Ocean 0.25 Ma, these islands were colonized by penguins from the subtropical Atlantic, 6000 km away, rather than by penguins from the sub-Antarctic Indian Ocean, 5000 km closer.
Programme: 354
|
|
Lyard F.H. & Le Provost C. (1997). Energy budget of the tidal hydrodynamic model FES94.1. Geophysical research letters, 24(6), 687–690.
|
Steffensen, J.P.; Andersen, K.K.; Bigler, M.; Clausen, H.B.; Dahl-Jensen, D.; Fischer, H.; Goto-Azuma, K.; Hansson, M.; Johnsen, S.J.; Jouzel, J.; Masson-Delmotte, V.; Popp, T.; Rasmussen, S.O.; Rothlisberger, R.; Ruth, U.; Stauffer, B.; Siggaard-Andersen, M.-L.; Sveinbjornsdottir, A.E.; Svensson, A.; White, J.W.C. (2008). High-Resolution Greenland Ice Core Data Show Abrupt Climate Change Happens in Few Years. Science, 321(5889), 680–684.
Abstract: The last two abrupt warmings at the onset of our present warm interglacial period, interrupted by the Younger Dryas cooling event, were investigated at high temporal resolution from the North Greenland Ice Core Project ice core. The deuterium excess, a proxy of Greenland precipitation moisture source, switched mode within 1 to 3 years over these transitions and initiated a more gradual change (over 50 years) of the Greenland air temperature, as recorded by stable water isotopes. The onsets of both abrupt Greenland warmings were slightly preceded by decreasing Greenland dust deposition, reflecting the wetting of Asian deserts. A northern shift of the Intertropical Convergence Zone could be the trigger of these abrupt shifts of Northern Hemisphere atmospheric circulation, resulting in changes of 2 to 4 kelvin in Greenland moisture source temperature from one year to the next.
Programme: 458
|
|
Challet E., Bost C.A., Handrich Y., Gendner J.P. & Le Maho Y. (1994). Behavioural time budget of breeding king penguins (Aptenodytes patagonica). J. Zool. (Lond.), 233(4), 669–681.
|
|
Bour M. & Cara M. (1997). Test of the empirical Green's function method on moderate size earthquake. Bulletin of the seismological society of america, 87(3), 668–683.
|
|
ANGELIER F, MOE B, CLEMENT-CHASTEL C, BECH C, CHASTEL O. (2007). Corticosterone levels in relation to change of mate in Black-legged kittiwakes. Condor, 109, 668–674.
|
|
Monna F., C. Petit, J.-P. Guillaumet, I. Jouffroy-Bapicot, C. Blanchot, J. Dominik, R. Losno, H. Richard, J. Lévêque, and C . Chateau. (2004). History and Environmental Impact of Mining Activity in Celtic Aeduan Territory Recorded in a Peat Bog (Morvan, France). Environ. Sci. Technol., 38, 665–673.
|
|
Jones O.R., Gaillard J.-M., Tuljapurkar S., Alho J.S., Armitage K.B., Becker P.H., Bize P., Brommer J., Charmantier A., Charpentier M., Clutton-Brock T., Dobson F.S., Festa-Bianchet M., Gustafsson L., Jensen H., Jones C.G., Lillandt B.-G., McCleery R., Merilä J., Neuhaus P., Nicoll M.A.C., Norris K., Oli M.K., Pemberton J., Pietiäinen H., Ringsby T.H., Roulin A., Saether J.M., Setchell J.M., Sheldon B.C., Thompson P.M., Weimerskirch H., Wickings E.J., Coulson T. (2008). Senescence rates are determined by ranking on the fast-slow life history continuum. ECOLOGY LETTERS, 11, 664–673.
|
|
Bussy M., Montagner J.P. & Romanowicz B. (1993). Tomographic study of upper mantle attenuation in the pacific Ocean. Geophysical research letters, 20(8), 663–666.
|
|
Martin A.R., Poncet S., Barbraud C., Foster E., Fretwell P., Rothery P. (2009). The white-chinned petrel (Procellaria aequinoctialis) on South Georgia: population size, distribution and global significance. Polar Biol., 32, 655–661.
|
