In 1869, Scottish naturalist Charles Wyville Thomson conducted dredging operations aboard the HMS Porcupine in the North Atlantic at depths exceeding 2,000 fathoms. Prior to this expedition, the prevailing abiotic hypothesis proposed by Edward Forbes maintained that marine life could not exist below 300 fathoms due to extreme pressure, perpetual darkness, and frigid temperatures. Thomson’s dredging retrieved diverse echinoderms, sponges, and crustaceans, disproving Forbes's depth limit. Crucially, Thomson noted that the benthic specimens exhibited fully developed functional eyes despite the absence of solar illumination at those abyssal depths. Rather than attributing this ocular preservation to residual surface-derived light, Thomson posited that the organisms relied on illumination generated locally by bioluminescent deep-sea fauna. Furthermore, thermal measurements recorded during the survey revealed distinct temperature stratification in deep water masses, demonstrating that abyssal currents actively transferred cold polar waters toward the equator.
According to the passage, which of the following accounts for Wyville Thomson’s explanation regarding the presence of functional eyes in deep-sea organisms?
- The organisms utilized illumination generated locally by bioluminescent deep-sea species.Answer
- BFaint traces of surface sunlight were able to penetrate the water column to depths exceeding 2,000 fathoms.
- CCold polar currents supplied essential metabolic nutrients required to sustain deep-water optic structures.
- DThe ocular structures were non-functional vestigial traits inherited from surface-dwelling ancestors.
- EThe extreme hydrostatic pressure below 300 fathoms altered the physical development of optic tissues.