Predicting biosignatures for nutrient-limited biospheres

• DOI: 10.1093/mnras/stac2086
• Publication Date: 2022-07-30T02:49:38Z
• Authors: A E Nicholson; S J Daines; N J Mayne; J K Eager-Nash; T M Lenton; K Kohary
• Keywords: Extraterrestrial Life; Planetary habitability

With the characterisations of potentially habitable planetary atmospheres on horizon, search for biosignatures is set to become a major area research in coming decades. To understand atmospheric characteristics that might indicate alien life we must abiotic planet and how interacts with its environment. In field biogeochemistry, sophisticated models life-environment coupled systems demonstrate many assumptions specific Earth-based life, e.g. ATP maintenance costs, are unnecessary accurately model biosphere. We explore simple single-species microbial biosphere produces CH4 as byproduct microbes' energy extraction - known type I biosignature. although significantly changing biological parameters has large impact biosphere's total population, such changes have only minimal strength resulting biosignature, while limited by H2 availability. extend include more accurate harvesting show adjusting microbe can lead regime change where becomes availability no longer fully exploits available H2, impacting that, nutrient biosphere, identifying limiting nutrient, understanding processes control abundance, determining ability exploit it, fundamental making biosignature predictions than details population dynamics