A1 Refereed original research article in a scientific journal
Global biogeographic patterns in bipolar moss species
Authors: Biersma EM, Jackson JA, Hyvonen J, Koskinen S, Linse K, Griffiths H, Convey P
Publisher: ROYAL SOC
Publication year: 2017
Journal: Royal Society Open Science
Journal name in source: ROYAL SOCIETY OPEN SCIENCE
Journal acronym: ROY SOC OPEN SCI
Article number: ARTN 170147
Volume: 4
Issue: 7
Number of pages: 13
ISSN: 2054-5703
DOI: https://doi.org/10.1098/rsos.170147
Self-archived copy’s web address: https://research.utu.fi/converis/portal/detail/Publication/26592194
Abstract
A bipolar disjunction is an extreme, yet common, biogeographic pattern in non-vascular plants, yet its underlyingmechanisms (vicariance or long-distance dispersal), origin and timing remain poorly understood. Here, combining a large-scale population dataset and multiple dating analyses, we examine the biogeography of four bipolar Polytrichales mosses, common to the Holarctic (temperate and polar Northern Hemisphere regions) and the Antarctic region (Antarctic, sub-Antarctic, southern South America) and other Southern Hemisphere (SH) regions. Our data reveal contrasting patterns, for three species were of Holarctic origin, with subsequent dispersal to the SH, while one, currently a particularly common species in the Holarctic (Polytrichum juniperinum), diversified in the Antarctic region and from here colonized both the Holarctic and other SH regions. Our findings suggest long-distance dispersal as the driver of bipolar disjunctions. We find such inter-hemispheric dispersals are rare, occurring on multi-million-year timescales. High-altitude tropical populations did not act as trans-equatorial 'steppingstones', but rather were derived from later dispersal events. All arrivals to the Antarctic region occurred well before the Last Glacial Maximum and previous glaciations, suggesting that, despite the harsh climate during these past glacial maxima, plants have had a much longer presence in this southern region than previously thought.
A bipolar disjunction is an extreme, yet common, biogeographic pattern in non-vascular plants, yet its underlyingmechanisms (vicariance or long-distance dispersal), origin and timing remain poorly understood. Here, combining a large-scale population dataset and multiple dating analyses, we examine the biogeography of four bipolar Polytrichales mosses, common to the Holarctic (temperate and polar Northern Hemisphere regions) and the Antarctic region (Antarctic, sub-Antarctic, southern South America) and other Southern Hemisphere (SH) regions. Our data reveal contrasting patterns, for three species were of Holarctic origin, with subsequent dispersal to the SH, while one, currently a particularly common species in the Holarctic (Polytrichum juniperinum), diversified in the Antarctic region and from here colonized both the Holarctic and other SH regions. Our findings suggest long-distance dispersal as the driver of bipolar disjunctions. We find such inter-hemispheric dispersals are rare, occurring on multi-million-year timescales. High-altitude tropical populations did not act as trans-equatorial 'steppingstones', but rather were derived from later dispersal events. All arrivals to the Antarctic region occurred well before the Last Glacial Maximum and previous glaciations, suggesting that, despite the harsh climate during these past glacial maxima, plants have had a much longer presence in this southern region than previously thought.
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