Question

The following passage is adapted from an article exploring the history of deep-sea oceanography.

[Paragraph 1]
For decades, marine biologists operated under the assumption that all life on Earth was ultimately dependent on sunlight. Photosynthesis was seen as the foundational process of the global food web, capturing solar energy to sustain primary producers, which in turn nourished herbivorous and carnivorous species alike. The sunlit upper layers of the ocean, known as the photic zone, were therefore believed to be the primary engine of marine biological productivity. The abyssal plains, shrouded in perpetual darkness, were assumed to be biological deserts, supported only by the sparse, decaying organic matter—often called 'marine snow'—that slowly drifted down from the surface.

[Paragraph 2] (lines 12–25)
This long-standing paradigm was shattered in 1977 during an expedition by the research submersible Alvin to the Galapagos Rift, a volcanic ridge on the ocean floor. Scientists discovered hydrothermal vents—fissures where superheated, mineral-rich water spews from the Earth's crust into the freezing ocean depths. To the researchers' astonishment, these vents were surrounded by dense, thriving communities of bizarre organisms, including giant tube worms, blind crabs, and massive clusters of clams. Rather than relying on sunlight, these organisms thrived on chemical energy. Specialized bacteria oxidized hydrogen sulfide dissolved in the vent fluids, converting it into organic matter through a process known as chemosynthesis. This discovery established that complex, highly productive ecosystems could flourish in the complete absence of solar radiation, fundamentally redefining the boundaries of life on Earth.

Which of the following statements best describes the main idea of the second paragraph (lines 12–25)?