Gillen D’Arcy Wood writes:

In the summer of 1977, on a field trip in northern Patagonia, the American archaeologist Tom Dillehay made a stunning discovery. Digging by a creek in a nondescript scrubland called Monte Verde, in southern Chile, he came upon the remains of an ancient camp. A full excavation uncovered the trace wooden foundations of no fewer than 12 huts, plus one larger structure designed for tool manufacture and perhaps as an infirmary. In the large hut, Dillehay found gnawed bones, spear points, grinding tools and, hauntingly, a human footprint in the sand. The ancestral Patagonians—inhabitants of Tierra del Fuego and the Magellan Straits—had erected their domestic quarters using branches from the beech trees of a long-gone temperate forest, then covered them with the hides of vanished ice age species, including mastodons, saber-toothed cats, and giant sloths.

Fire pits indicated where the Monte Verdeans cooked their food. Grinding stones helped fashion their spear points for hunting while, scattered on the excavated floor of the large hut, Dillehay uncovered the fossilized remains of more than 20 medicinal plants, including a species of giant kelp, Durvillaea antarctica. The species was discovered in the 1830s by explorer Jules-Sébastien Dumont D’Urville, who identified the indigenous giant seaweed during the first of his three Southern Ocean voyages on the beaches of the Falkland Islands, east of Tierra del Fuego. Because seaweed is short-lived, the Durvillaea fossil provided the most precise available date for human occupation of the site. Radiocarbon analysis of charcoal, worked wooden artifacts, and the leftover bones of a mastodon meal confirmed the presence of ice age hunter-gatherers at Monte Verde 14,500 years ago, at least 1,000 years prior to any existing archaeological evidence for human colonization of the Americas, North or South.

During his Beagle voyage into the south Atlantic Ocean in the 1830s, Charles Darwin wondered how the Patagonians had come to venture so far south, into sub-polar cold. D’Urville’s giant kelp, it turned out, was a key to their southern passage. On the deck of the Beagle, when Darwin shook out the entangled roots of another giant kelp species ubiquitous in southern waters, Macrocystis pyrifera, he discovered a living zoo: from the microorganic coral incrustations decorating each frond to innumerable polyps, algae, mollusks, and crustacea to cuttlefish, crabs, starfish, sea eggs, crawling nereids, and schools of small fish of stunning variety. This marine banquet in turn fed the ever-present birds—the cormorants, albatrosses, and petrels that circled the Beagle—as well as otters, seals, and dolphins that crowded the bleak channels and islands of Tierra del Fuego. Contemplating this colorful menagerie, Darwin conjectured that nowhere else in the world did so many species depend for their existence on a single plant. These included the maritime peoples of Tierra del Fuego, who had adapted somehow to the sub-Antarctic cold and sustained themselves on fish and seal flesh garnished by dried tidbits of the seaweed itself. Were the keystone kelp to be destroyed, a mass extinction, including humans, would inevitably follow. Both Macrocystis pyrifera and Durvillaea antarctica were critical to the survival of the first people in the Americas. Their extinction, it turned out, had a more modern, pernicious cause. [Continue reading…]