Passage A: The discovery of extremophiles near hydrothermal vents on the ocean floor suggests that life on Earth likely originated in these high-pressure, high-temperature environments. These deep-sea vents provide a steady source of chemical energy, such as hydrogen sulfide, which could fuel the synthesis of organic molecules independent of sunlight. This chemoautotrophic origin theory is supported by the genetic proximity of many ancient microbes to modern vent-dwelling species. By providing a stable environment protected from the surface's harsh UV radiation and asteroid impacts, the deep ocean was the ideal cradle for the first biological systems. Passage B: Despite the popularity of the vent theory, the origin of life likely occurred in shallow, terrestrial hot springs. These environments allow for cycles of wetting and drying, which are essential for the polymerization of amino acids into complex proteins—a process that is chemically difficult in the dilute environment of the open ocean. Furthermore, the high temperatures of hydrothermal vents would more likely decompose fragile organic precursors than foster their assembly. The presence of specific minerals in terrestrial pools acts as a catalyst for life's earliest reactions, a feature not replicated in the chemistry of the deep sea.