Paleo-Rock-Hosted Life on Earth and the Search on Mars: A Review and Strategy for Exploration.

ABSTRACT: Here we review published studies on the abundance and diversity of terrestrial rock-hosted life, the environments it inhabits, the evolution of its metabolisms, and its fossil biomarkers to provide guidance in the search for life on Mars. Key findings are (1) much terrestrial deep subsurface metabolic activity relies on abiotic energy-yielding fluxes and in situ abiotic and biotic recycling of metabolic waste products rather than on buried organic products of photosynthesis; (2) subsurface microbial cell concentrations are highest at interfaces with pronounced chemical redox gradients or permeability variations and do not correlate with bulk host rock organic carbon; (3) metabolic pathways for chemolithoautotrophic microorganisms evolved earlier in Earth's history than those of surf

SUBMITTER: Onstott TC 

PROVIDER: S-EPMC6786346 | biostudies-literature | 2019 Oct

REPOSITORIES: biostudies-literature