
DancingintheDark:Chemosynthesis and SymbiosisColleen M.CavanaughHarvard University20KUX288810U00141470 MC2
Dancing in the Dark: Chemosynthesis and Symbiosis Colleen M. Cavanaugh Harvard University

SYMBIOSISGr. from syn with + bioun to live...des Zusammenlebens ungleichnamiger Organismen..A.de Bary 1879WidespreadbetweenEukaryaandBacteria/Archaea
SYMBIOSIS “.des Zusammenlebens ungleichnamiger Organismen.” A. de Bary 1879 Gr. from syn with + bioun to live Widespread between Eukarya and Bacteria / Archaea

Microbial diversityBacteria/ArchaeaEnergy:Light(Photo-)Chemical(Chemo-)· CarbonOrganic C(Hetero-,‘other")(Auto-‘self")Inorganic C
Microbial diversity: Bacteria / Archaea • Energy: Light (Photo-) Chemical (Chemo-) • Carbon Organic C (Hetero-, ‘other’) Inorganic C (Auto- ‘self’)

Symbiosis:ecological andevolutionary potentialMichaelMcGrathCows, termitesCellulolytic symbiosesLegumesN,-fixing symbioses
Cows, termites Cellulolytic symbioses Legumes N2-fixing symbioses Symbiosis: ecological and evolutionary potential

Endosymbioticoriginof eukaryotic cellsPROKARYOTEEUKARYOTECHLOROPLASTMITOCHONDRIONFREE LIVING“n-BLUE-GREENALGA3ONUCLEUSO8FREE LIVINGAEROBICBACTERIUMNUCLEUSW.F.DoolittlePROTOFIIKARYOTE
Endosymbioticorigin of eukaryotic cells W.F. Doolittle

Deep-seaHydrothermal VentsDiscoveredin1977Biologicalphenomena20707:21:03850/0212/23/8117:12Revolutionizedperceptions ofDeep seaPrimaryproductionSymbioses
Deep-sea Hydrothermal Vents • Discovered in 1977 • Biological phenomena Revolutionized perceptions of Deep sea Primary production Symbioses

Chemosynthesis:Production oforganic compounds usinginorganic compoundsfor both energy and carbon
Production of organic compounds using inorganic compounds for both energy and carbon. Chemosynthesis:

ChemosynthesisEarthMarsEuropa
Chemosynthesis. Mars Earth Europa

ChemoautotrophsSubstrates for EnergyGeneration:H2S + O2CarbonMetabolism:C1→C
Carbon Metabolism: C1 C3 Substrates for Energy Generation: H2S + O2 Chemoautotrophs

ResearchQuestionsHowwidespreadarethesesymbiosesin nature?Whoarethesymbionts?Phylogenetic affiliations? Metabolic diversity?Host/symbiontassociationsspecies-specific?Role in the cycling of energy,carbon, and nutrients?Evolution of chemosynthetic symbiontsparallelevolution ofeukaryoticorganelles?
Research Questions How widespread are these symbioses in nature? Who are the symbionts? Phylogenetic affiliations? Metabolic diversity? Host/symbiont associations species-specific? Role in the cycling of energy, carbon, and nutrients ? Evolution of chemosynthetic symbionts parallel evolution of eukaryotic organelles?