The Evolutionary History of the Antarctic Flora
How long has the extant flora been present in the Antarctic? Glaciological reconstructions propose that most areas in Antarctica were covered by thick ice sheets throughout the Last Glacial Maximum (LGM; ~22-18 kya) as well as previous glaciations, suggesting terrestrial life must have been extremel...
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ftunivcam:oai:www.repository.cam.ac.uk:1810/269736 2023-07-30T03:59:24+02:00 The Evolutionary History of the Antarctic Flora Biersma, Elisabeth Machteld 2017-11-10T15:00:20Z application/pdf https://doi.org/10.17863/CAM.16667 https://www.repository.cam.ac.uk/handle/1810/269736 en eng Jesus College Department of Plant Sciences University of Cambridge doi:10.17863/CAM.16667 https://www.repository.cam.ac.uk/handle/1810/269736 No Creative Commons licence (All rights reserved) All Rights Reserved https://www.rioxx.net/licenses/all-rights-reserved/ Antarctic Antarctica Moss Bryophyte Population genetics biogeography genetics evolution Last Glacial Maximum Biology Polar Arctic cryptogam spore distribution phylogenetic phylogenetics refugia flora climate Thesis Doctoral Doctor of Philosophy (PhD) PhD in Plant Sciences 2017 ftunivcam https://doi.org/10.17863/CAM.16667 2023-07-10T21:36:18Z How long has the extant flora been present in the Antarctic? Glaciological reconstructions propose that most areas in Antarctica were covered by thick ice sheets throughout the Last Glacial Maximum (LGM; ~22-18 kya) as well as previous glaciations, suggesting terrestrial life must have been extremely limited during these periods. In contrast, recent biogeographic and genetic studies support most extant groups of Antarctic terrestrial fauna having survived past glaciations in situ. However, studies on the origin and age of the Antarctic flora remain sparse. Applying population genetic, phylogeographic and divergence time analyses I assessed the global biogeography, origin and age of several abundant Antarctic moss species, including: four Polytrichaceae mosses, characterised by having bipolar distributions, the most common (~45% of species) distribution pattern amongst Antarctic mosses; the globally widespread moss Ceratodon purpureus; the bank-forming moss Chorisodontium aciphyllum, also known for its old sub-fossils in Antarctica and long-term viability from revival experiments; and, lastly, the genus Schistidium, the most species-rich moss genus in Antarctica, including many endemic species. Genetic analyses revealed evidence of long-term (multi-million year) survival of plants in Antarctica (several species of Schistidium, Ceratodon purpureus, and possibly Polytrichum juniperinum). However, evidence for a likely more recent (<100 ky) arrival of Chorisodontium aciphyllum was also found. Some species revealed multiple separate dispersal events to the Antarctic, suggesting the region may be less isolated for spore-dispersed organisms than previously thought. Evidence for increased genetic diversity in the northern maritime Antarctic compared to other regions point at it including potential refugial areas. Furthermore, genetic patterns revealed geographic features that enable and limit the connectivity of bryophytes globally as well as in Antarctica. This study suggests that, despite the harsh polar climate ... Doctoral or Postdoctoral Thesis Antarc* Antarctic Antarctica Arctic Apollo - University of Cambridge Repository Antarctic Arctic Kya ENVELOPE(8.308,8.308,63.772,63.772) The Antarctic |
institution |
Open Polar |
collection |
Apollo - University of Cambridge Repository |
op_collection_id |
ftunivcam |
language |
English |
topic |
Antarctic Antarctica Moss Bryophyte Population genetics biogeography genetics evolution Last Glacial Maximum Biology Polar Arctic cryptogam spore distribution phylogenetic phylogenetics refugia flora climate |
spellingShingle |
Antarctic Antarctica Moss Bryophyte Population genetics biogeography genetics evolution Last Glacial Maximum Biology Polar Arctic cryptogam spore distribution phylogenetic phylogenetics refugia flora climate Biersma, Elisabeth Machteld The Evolutionary History of the Antarctic Flora |
topic_facet |
Antarctic Antarctica Moss Bryophyte Population genetics biogeography genetics evolution Last Glacial Maximum Biology Polar Arctic cryptogam spore distribution phylogenetic phylogenetics refugia flora climate |
description |
How long has the extant flora been present in the Antarctic? Glaciological reconstructions propose that most areas in Antarctica were covered by thick ice sheets throughout the Last Glacial Maximum (LGM; ~22-18 kya) as well as previous glaciations, suggesting terrestrial life must have been extremely limited during these periods. In contrast, recent biogeographic and genetic studies support most extant groups of Antarctic terrestrial fauna having survived past glaciations in situ. However, studies on the origin and age of the Antarctic flora remain sparse. Applying population genetic, phylogeographic and divergence time analyses I assessed the global biogeography, origin and age of several abundant Antarctic moss species, including: four Polytrichaceae mosses, characterised by having bipolar distributions, the most common (~45% of species) distribution pattern amongst Antarctic mosses; the globally widespread moss Ceratodon purpureus; the bank-forming moss Chorisodontium aciphyllum, also known for its old sub-fossils in Antarctica and long-term viability from revival experiments; and, lastly, the genus Schistidium, the most species-rich moss genus in Antarctica, including many endemic species. Genetic analyses revealed evidence of long-term (multi-million year) survival of plants in Antarctica (several species of Schistidium, Ceratodon purpureus, and possibly Polytrichum juniperinum). However, evidence for a likely more recent (<100 ky) arrival of Chorisodontium aciphyllum was also found. Some species revealed multiple separate dispersal events to the Antarctic, suggesting the region may be less isolated for spore-dispersed organisms than previously thought. Evidence for increased genetic diversity in the northern maritime Antarctic compared to other regions point at it including potential refugial areas. Furthermore, genetic patterns revealed geographic features that enable and limit the connectivity of bryophytes globally as well as in Antarctica. This study suggests that, despite the harsh polar climate ... |
format |
Doctoral or Postdoctoral Thesis |
author |
Biersma, Elisabeth Machteld |
author_facet |
Biersma, Elisabeth Machteld |
author_sort |
Biersma, Elisabeth Machteld |
title |
The Evolutionary History of the Antarctic Flora |
title_short |
The Evolutionary History of the Antarctic Flora |
title_full |
The Evolutionary History of the Antarctic Flora |
title_fullStr |
The Evolutionary History of the Antarctic Flora |
title_full_unstemmed |
The Evolutionary History of the Antarctic Flora |
title_sort |
evolutionary history of the antarctic flora |
publisher |
Jesus College |
publishDate |
2017 |
url |
https://doi.org/10.17863/CAM.16667 https://www.repository.cam.ac.uk/handle/1810/269736 |
long_lat |
ENVELOPE(8.308,8.308,63.772,63.772) |
geographic |
Antarctic Arctic Kya The Antarctic |
geographic_facet |
Antarctic Arctic Kya The Antarctic |
genre |
Antarc* Antarctic Antarctica Arctic |
genre_facet |
Antarc* Antarctic Antarctica Arctic |
op_relation |
doi:10.17863/CAM.16667 https://www.repository.cam.ac.uk/handle/1810/269736 |
op_rights |
No Creative Commons licence (All rights reserved) All Rights Reserved https://www.rioxx.net/licenses/all-rights-reserved/ |
op_doi |
https://doi.org/10.17863/CAM.16667 |
_version_ |
1772810211742973952 |