Nitrogen studies in sub-Antarctic terrestrial environments

The task here, however, is to address the physiological ecology of plants. Traditionally, this has deployed two approaches: the in vivo, in which physiological processes were studies at the whole plant or organ level, in field and laboratory, and the in vitro, in which cellular and subcellular processes were dissected in order to understand the mechanisms underlying physiological responses. Bringing us closer to the astronomy fraternity there is a third approach, the in silico, in which computer simulation and graphic modelling provide tools for the study of past and future plants and processes.

This contribution attempts to look back to the past, to the origins of life, in order to understand the selectivity in the use of mineral elements and their roles in extant physiological ecology. What do we know of the conditions present on early Earth that shaped the origin and evolution of life and determined the selection and roles of the mineral elements that are now essential for plant growth? The emergence of life may have occurred in a fairly short interval, microfossils are reported in 3.5-Gyr rock and there is evidence of biogenic carbon isotope fractionation in 3.8-Gyr rock.

The early Earth on which life appeared was very different to the planet we inhabit today. Life originated not in a quiescent, favourable environment but rather a violent, impact-ridden one, characterised by enormous tides, intense volcanic activity and heavy meteoritic bombardment. Current thinking is that this early Earth had an atmosphere rich in carbon dioxide and nitrogen, rather than one of methane and ammonia - conditions rather unfavourable for cooking up prebiotic soups.