The “tree” here is the taxonomic tree of the organisms analysed, coloured by major group. The red bars on the outside of the tree show how many species have been

Biosignatures & Paleobiology Status Report eartharxiv.org November 12, 2025 Life processes and requirements resulting in the production of specific molecular structures that, if preserved, can function as biosignatures. B) OM

Depiction of the many factors affecting η⊕ and measurements therein. The three main colors offer a loose categorization into planetary, stellar, and statistical issues (red, purple, and blue, respectively), with

Artist concept of a cloudy Earth-like exoplanet with colorful biota in the clouds. Adam B. Langeveld/Carl Sagan Institute. Adapted from NASA/Ames/JPL-Caltech. An exoplanet with dense or even total cloud cover

Wind fields in our imposed TOA 𝐴𝑏 = 0.6 case. Top left: horizontal wind field at 250 hPa. Top right: Divergent component of the circulation, and the vertical pressure velocity

c. Approximate ages for the origin of nitrogenase isoforms are based on geochemical12 and phylogenetic data. — biorxiv.org Nitrogen isotope fractionation (ε15N) in sedimentary rocks has provided evidence for biological