Featured Science Paper
Does understanding its terrestrial life alter Antarctica's established glacial history?
A truly cross-disciplinary study from British Antarctic Survey scientists of life on Antarctica’s frozen wastes has questioned current understanding of Antarctic glacial history and millions of years of biological development.
Antarctica is a continent locked in ice – over 99% is covered by permanent ice and snow – and there is clear evidence that, as recently as the Last Glacial Maximum (LGM) (~20,000 years ago), ice sheets were both thicker and much more extensive than they are now. Ice sheet modelling of both the LGM and previous ice maxima shows that most, if not all, ground that is currently ice-free would have been obliterated. This has led to a widely held perception that all of the Mesozoic (pre-glacial) terrestrial life of Antarctica was wiped out by successive and deepening glacial events.
The conclusion of such widespread destruction is that most, possibly all, terrestrial life found on the continent today has colonised Antarctica during subsequent periods of glacial retreat. However, several recent and complementary areas of biological and geological research provide a fundamental challenge to the current reconstruction of Antarctic glacial history. Emerging insights suggest that Antarctic terrestrial organisms have been continuously isolated in situ on a multi-million year timescale, even going back before the final phases of the break-up of the Gondwana supercontinent (more than 40 million years ago). This new and complex terrestrial biogeography parallels recent work suggesting greater regionalisation and evolutionary isolation than previously thought in Antarctica’s marine fauna.
This paper summarises and synthesizes evidence across these lines of research. The findings require the adoption of a new biological paradigm for Antarctica and directly challenge current understanding of Antarctic glacial history. This has major implications for our understanding of Antarctica’s key role in the Earth System.
Antarctic terrestrial life – challenging the history of the frozen continent?
P. Convey (BAS), J. Gibson (University of Tasmania, Hobart), C-D. Hillenbrand (BAS), D. Hodgson (BAS), P. Pugh (Anglia Ruskin University, Cambridge), J. Smellie (BAS) and M. Stevens (Massey University, New Zealand)
Biological Reviews, 83, No. 2, 103-117, 2008