The Voyage of Sorcerer II
The Expedition That Unlocked the Secrets of the Ocean’s Microbiome by Craig Venter and David Ewing Duncan
by Lincoln Paine: A Sea of Words
January 25, 2024
About 2,500 years ago, the Temple of Apollo at Delphi bore the inscription gnothi sauton: know yourself. Some interpret this to mean that people should know their station with respect to their betters, that they should know their soul, and that they should know their place in the universe. Modern science allows for still more complex interpretations: to know our own genetic composition and our place in a world of microbiomes, “the combined genetic material of the microorganisms in a particular environment,” from our bodies to the depths of the Mariana Trench.
Among the key figures in the development of this science is Craig Venter. In 1995, his company Celera was the first to sequence the genome of an entire organism, Haemophilus influenzae. Five years later, Celera and the international Human Genome Project, led by Francis Collins, were recognized for their contributions to generating the first draft sequence of the human genome.
Venter’s next goal was to search for microbes in the ocean, which many believed to be fewer and less diverse than he did. To test his hypothesis, he fitted out his 95-foot sloop Sorcerer II to circumnavigate the world in search of oceanic microbes. Co-authored by science journalist David Ewing Duncan, The Voyage of Sorcerer II combines the history of the complex science of genomics and metagenomics (the genetic analysis of all microbes in a large sample), with a narrative of the voyages of the Sorcerer II, especially the first, the Global Ocean Sampling Expedition (2003–2005).
After sampling the waters of the Sargasso Sea, 200 liters at a time, the Sorcerer II began its 32,000-mile circumnavigation at Halifax, sailed south along the eastern seaboard, through the Caribbean and Panama Canal and on to the Galápagos Islands. There, over the course of six weeks, they collected eleven samples in a range of environments, from a hot underwater sulfur vent and coral reef to a mangrove swamp and freshwater pond.
This was a worthwhile stop in its own right, but Venter saw a direct connection between his work and that of Charles Darwin. Comparing oneself with the father of evolution might be viewed as overblown, but in Venter’s case it is not inapt. On the voyage of the Beagle (1831–36), Darwin — who embarked as a 22-year-old prospective clergyman — collected more than 1,500 species of flora and fauna from which he made the observations published in his revolutionary Origin of the Species (1859).
Over the course of this first and three subsequent expeditions — in the Baltic, Mediterranean, and west coast of North America — Venter’s teams took nearly 500 water samples, most in the photic zone, from which they extracted millions of bacterial genes and proteins, and viruses.
Analysis of all this data, and that from thousands of subsequent efforts has given us some insight into the life of the roughly octillion (1029) microorganisms in the ocean. We know, for instance, that the oceanic microbial ecosystem “feeds and supports those phytoplankton” that work the ocean biological carbon pump by producing 40 percent of atmospheric oxygen and consuming and sequestering about the same percentage of carbon dioxide, processes essential for life as we know it.
These microbial ecosystems are affected by human activity, though in ways that we cannot yet divine. As a paper in Nature Reviews Microbiology put it, “the impact of climate change will depend heavily on responses of microorganisms, which are essential for achieving an environmentally sustainable future.” Put another way, microbes will adapt to a changing climate, but not necessarily in ways beneficial to humans and other plants and animals.
As for our bodies? Sequencing the human genome was only a first step in knowing our genetic selves. It was the study of environmental biomes like those sampled in the Sorcerer II expeditions that laid the groundwork for the study of the human biome, with its 10,000 species of bacteria, which total about 38 trillion (1012) per person.
True to its name, the Sorcerer II is a teller of fortunes. While scientists are publishing their findings on bits and pieces of analysis, what it all means is as inscrutable as a Delphic oracle. “Understand[ing] the inner relationship of the twenty thousand genes in a human, and the evolutionary steps it took to get there … is far beyond our current state of biology, and of meaningful intellectual pursuit,” says Venter. With the technology available to us now and in the coming decades, we may divine “some additional principles of biology. Until then, we are still very much in a descriptive world, and that’s probably where biology will be for the next century at least.”
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© 2024 Lincoln Paine
