Table 3a.

Environments Available for the Emergence of Life

System	Prebiotic chemistry		Emergence of life
Properties	Advantages	Disadvantages	Advantages	Disadvantages
Submarine hydrothermal vents
Temperatures >100–150°C	Facilitates molecular interactions	Agitation can break up molecules		Temperatures too high unless the vents are inactive and flushed with lower-temperature seawater
Fluid dynamics	Low in porous edifice	High in vent throat	Diffusion of nutrients	Disruption if too high
pH—alkaline-acid	Favors prebiotic processes		Any pH for protocells
Ionic strength	Variable		Salts necessary for protocells
Energy sources	Heat; exothermal breakdown of organic molecules		Breakdown of organic molecules; redox reactions of reactive minerals; gradients (pH, temperature…)
Mineralogy, e.g., sulfides and various mafic/ultramafic minerals and their alteration products	Reactive surfaces favor molecule-organic interactions (Table 1)		Energy from redox reactions at mineral surfaces
Element availability	CHNOPS		CHNOPS, Cu, Fe, Ni, Zn…
Porous structures (minerals, edifices, e.g., beehive structures)	Concentration of prebiotic components, compartmentalization		Protected environment for protocells
Protection from external environment	UV protection, disruption caused by impacts		Protected environment—from UV, etc.
Distribution of products	In hydrothermal fluid effluent		In hydrothermal fluid effluent