Location, location, location: survival of Antarctic biota requires the best real estate

Abstract

The origin of terrestrial biota in Antarctica has been debated since the discovery of springtails on the first historic voyages to the southern continent more than 120 years ago. A plausible explanation for the long-term persistence of life requiring ice-free land on continental Antarctica has, however, remained elusive. The default glacial eradication scenario has dominated because hypotheses to date have failed to provide a mechanism for their widespread survival on the continent, particularly through the Last Glacial Maximum when geological evidence demonstrates that the ice sheet was more extensive than present. Here, we provide support for the alternative nunatak refuge hypothesis—that ice-free terrain with sufficient relief above the ice sheet provided refuges and was a source for terrestrial biota found today. This hypothesis is supported here by an increased understanding from the combination of biological and geological evidence, and we outline a mechanism for these refuges during successive glacial maxima that also provides a source for coastal species. Our cross-disciplinary approach provides future directions to further test this hypothesis that will lead to new insights into the evolution of Antarctic landscapes and how they have shaped the biota through a changing climate.

Floristic Similarities between the Lichen Flora of Both Sides of the Drake Passage: A Biogeographical Approach

“…The austral biogeographical group (13.7%) includes some species that may have originated on the old continent of Gondwana, as did many vascular plants [23,24] and bryophytes [25]. Finally, the Antarctic-subantarctic endemic group (16.9%) should be considered to be composed of pre-Pleistocene survivors of the ice ages that somehow found refuge in ice-free areas, mainly on rocky substrates in coastal regions or nunataks [23,26,27]. Interestingly, some cosmopolitan species, such as Collema tenax (Sw.) Ach.…”

Terrestrial nematodes from the Maritime Antarctic

“…Soil nematodes are one of the most important groups of the terrestrial fauna in Antarctica ( Maslen and Convey 2006 ) as they are abundant, taxonomically and functionally diverse and occupy a central position in the soil micro-food webs ( Adams et al 2014 ) and may have an impact on nutrient cycling and carbon dioxide emission, when soils thaw for a longer period of the year under climate change ( van den Hoogen et al 2019 ). In the challenging environmental conditions of the Antarctic, their distribution is limited to ice-free areas, where they have evolved throughout millions of years of climatic fluctuations in refugia ( Ebach et al 2008 , Convey et al 2020 , Stevens and Mackintosh 2023 ). The glaciations, long-term isolation, harsh climate and the patchy distribution of ice-free areas (present today where at least partially ice-free throughout repeated glacial maxima ( Newman et al 2009 )) are the main factors affecting the Antarctic nematode fauna origin/genesis (i.e.…”