Deep beneath the ocean swells lurk creatures never seen by people—or so some scientists thought in the late 1800s. In On the Origin of Species, Charles Darwin suggested the oceans had remained largely unchanged for millions of years and would contain living fossils of the past, providing proof of his idea of evolution. Others envisioned the deep ocean as a vast wasteland, filled only with extremely primitive life forms, or none at all. To settle the debate, the Royal Society of London launched a daring expedition—the voyage of the HMS Challenger—to map the ocean floor, to study seawater temperatures and chemistry, and to dredge up deep-sea organisms.
The voyage may have been “nothing less than a last chance to choose between God and Science,” writes the biogeochemist Richard Corfield in his 2003 book, The Silent Landscape: The Scientific Voyage of HMS Challenger. Work done aboard Challenger revolutionized researchers’ ideas about ...