Biosignature preservation
= Biosignature preservation
Retention of potential biological evidence through deposition, burial, alteration and exposure. <Organic molecules>, microscopic textures and <isotope fractionation> have different sensitivities to heating, oxidation and <ionizing radiation>. A former habitable environment can lack a recoverable <biosignature> if its record was destroyed; a preserved feature still requires tests against nonbiological origins and contamination.