Related by context. Frequent words. (Click for all words.) 60 biogenic 56 thermogenic 56 unicellular 56 nitrogen fixation 55 Cyanobacteria 55 hydrothermal 55 nonliving 55 macroevolution 55 methanogens 55 magmas 54 naturally occurring 54 biogeochemical 54 clathrates 53 isotope ratios 53 prokaryotes 53 archaea 53 stromatolites 53 meteorite impacts 52 methane hydrates 52 sorption 52 kerogen 52 marine sediments 52 depositional 52 bioaccumulation 52 chloroplast 52 isoprene 52 fossilization 52 thermochemical 52 naturally occuring 52 Snowball Earth 51 hydrothermal activity 51 nitrogen fixing 51 morphologies 51 isotopic composition 51 angiosperms 51 terrestrial ecosystems 51 endocrine disruption 51 nitrification 50 microbiota 50 volcanism 50 diatoms 50 hydrothermal vent 50 dynamical 50 magmatic 50 irreducibly complex 50 microbes 50 mud volcanoes 50 biogeochemistry 50 zeolites 50 organisms 50 Archaea 50 biotic 50 elemental composition 50 microfossils 50 pathophysiological 49 lignocellulose 49 anthropogenic 49 nucleation 49 systematics 49 hybridisation 49 eukaryotic 49 mineralizing 49 biota 49 alkanes 49 photosynthetic 49 eukaryotic cells 49 anaerobic bacteria 49 faunal 49 olivine 49 CO2 sequestration 49 iron oxides 49 osmium 49 galaxy formation 49 subsurface 49 phosphine 49 morphologically 49 isotopic 48 imprinted genes 48 lavas 48 multicellular organisms 48 biophysical 48 biochemical pathways 48 vertebrate animals 48 phytoplankton blooms 48 Carbon sequestration 48 microbial 48 Bt toxin 48 diatom 48 paleo 48 gut microbes 48 oxidization 48 mammalian brain 48 desiccation 48 cofactor 48 hydrological cycle 48 reactants 48 macroscopic 48 speciation 48 microorganisms 48 phenolic compounds 48 solar nebula