Location Location Location: Survival of Antarctic biota requires the best real-estate ...

• Main Authors: Stevens, Mark, Mackintosh, Andrew
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Zenodo 2023
• Subjects: springtails; ice-free; glacial refuge; cosmogenic dating; Nunatak; ice sheet; Antarc*; Antarctic; Antarctica; Ice Sheet; Springtail
• Online Access: https://dx.doi.org/10.5281/zenodo.7425717; https://zenodo.org/record/7425717

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 ... : Full details are in the download file " README_Dataset-SurvivalAntarcticBiota.md" Software and file formats used. All maps were created using the Antarctic GIS package 'Quantarctica' (https://www.qgis.org/en/site/about/case_studies/antarctica.html) in QGIS ver. 3.22.7. The ACBRs shown in figure 1 and Supplementary figures S1-S7 are included in an 'Environmental management' layer within Quantarctica and colours were chosen to match those used previously. For the land topography of Antarctica we used the shapefiles from 'Bedmachine' (downloaded from NSIDC, https://nsidc.org/data/nsidc-0756/versions/2) in QGIS ver. 3.22.7. Each input data file was saved as .csv files and imported individually into QGIS for: (1) all individual springtail occurrences (separated into each species), (2) geothermal sites (separated into large and small), (3) geochronological dated sites (separated into high refuge support, and low refuge support), and (4) eDNA signals of springtails. These data were then used to create figures 1 and ...