Final answer:
The hypothesis suggesting that life began near deep-sea hydrothermal vents is called the hydrothermal hypothesis, which posits that conditions around these vents could have facilitated the formation of organic molecules essential for life.
Step-by-step explanation:
The hypothesis that life originated in the depths of the ocean, near deep-sea hydrothermal vents, is referred to as the hydrothermal hypothesis. This idea is supported by the notion that these vents would have emitted molecules conducive to forming organic compounds. In the debate over the origins of life on Earth, the hydrothermal vents present an alternative to the panspermia hypothesis, which suggests life might have arrived on Earth via comets or meteorites, and the Miller-Urey experiment, which demonstrated the synthesis of organic molecules from inorganic precursors in what was thought to represent the early Earth's conditions. The fossilized remains of microbial mats by deep sea hydrothermal vents dating back 3.5 billion years lend credence to the hydrothermal hypothesis. This is just one of several scientific theories aimed at explaining life's natural genesis on our planet.