Edinburgh Research Explorer

Biological effects of high ultraviolet radiation on early Earth - a theoretical evaluation

Research output: Contribution to journalArticle

Related Edinburgh Organisations

Original languageEnglish
Pages (from-to)717-729
Number of pages13
JournalJournal of Theoretical Biology
Volume193
Issue number4
Publication statusPublished - 21 Aug 1998

Abstract

The surface of early Earth was exposed to both UVC radiation (<280 nm) and higher doses of UVB (280-315 nm) compared with the surface of present day Earth. The degree to which this radiation environment acted as a selection pressure on organisms and biological systems has rarely been theoretically examined with respect to the biologially effective irradiances that ancient organisms would receive. Here action spectra for DNA inactivation and isolated chloroplast inhibition are used to estimate biologically effective irradiances on archean Earth. Comparisons are made with present day Earth. The theoretical estimations on the UV radiation screening required to protect DNA on archean Earth compare well with field and laboratory observations on protection strategies found in present day microbial communities. They suggest that many physical and biological methods may have been effective and would have allowed for the radiation of life even under the high UV radiation regimes of archean Earth. Such strategies would also have provided;effective reduction of photoinhibition by UV radiation. The data also suggest that the UV regime on the surface of Mars is not a life limiting factor per se, although other environmental factors such as desiccation and low temperatures may contribute towards the apparent lack of a surface biota. (C) 1998 Academic Press.

    Research areas

  • CYANOBACTERIUM NOSTOC COMMUNE, UV-B RADIATION, SUNSCREEN PIGMENT, EARLY EVOLUTION, CARBON UPTAKE, REPAIR, DNA, PHOTOREACTIVATION, MICROORGANISMS, ATMOSPHERE

ID: 25229592