On the Backs of Tortoises: Darwin, the Galápagos, and the Fate of an Evolutionary Eden by Elizabeth Hennessy (review)

At the very moment i was asked to review Elizabeth Hennessy's excellent book, On the Backs of Tortoises, titillating headlines announced the retirement of Diego, a giant tortoise and Galápagos centenarian. The papers called him a stud, a sex machine, and a playboy tortoise among other anthropomorphisms. As the lone male survivor of Chelonoidas hoodensis, Diego saved his species by mating with eleven surviving females. Thanks to the amorous giant, scientists developed a successful captive breeding program that led to the repatriation of 8,000 juveniles to their native island of Española. Diego's unique history – which includes being sent to the San Diego Zoo in the 1930s, being returned to the Galápagos in the 1970s as a sybarite tortoise, and his headline-worthy retirement to the wilds of Española in early 2020 – illustrates the distinct role of humans in maintaining the archipelago as a natural laboratory and a living museum of evolution. By uniting thick description with political ecology and multispecies ethnography, geographer Hennessy explores the social-environmental entanglements and contradictions in this fraught relationship, and of our changing predilection toward the giant tortoise and the storied islands upon which they evolved.

Once a denizen of every continent except Antarctica and Australia, the giant tortoise was nearly hunted into extinction during the Pleistocene. By the time the twenty-six year-old Charles Darwin stepped ashore at the Galápagos in 1835, giant tortoises existed only there and on an atoll in the Indian Ocean. An active volcanic archipelago located 600 miles off the coast of Ecuador, the equatorial islands that comprise the Galápagos take their name from the Spanish word for tortoise. They lie at the intersection of three tectonic plates and the confluence of distinct ocean currents, fostering ecosystems adapted to unusually cool and dry tropical climates. Today, the archipelago's human population of 20,000 resides on only four of the 13 islands, while 97 percent of its land area lies protected within the Galápagos National Park.

Fifteen different species of giant tortoises once inhabited the islands and the differences Darwin observed contributed to his theory of evolution. Darwin's association with the plodding landlubber helped turn tortoises into the iconic reptiles of a lost world (and today both sagely emblazon tourist bric-a-brac). Yet, as Hennessy shows, the "charisma of iconic wildlife is not innate": it is a historical product and culturally situated (p. 14). Indeed, repopulating an "evolutionary Eden" with the appropriate tortoise species was not a matter of simply letting nature take its course, but the result of a complex political ecology.

First encountered by Spaniards in 1535, the archipelago was visited only sporadically until whalers began stopping regularly by the late eighteenth century. Like Darwin, the many famished sailors who preceded him alighted to feast on the savory, abundant, and easily captured tortoises. Hennessy argues that rather than discovering a lost world, the Beagle was just one piece of an expanding global economy that united empirical science with imperial expansion that swept over the archipelago while literally consuming its tortoises. The details may have changed today but just as Darwin's activities and those of his compatriots rested on the backs of tortoises, so too does today's tourist industry and its ever-outward capital flows. This is, as Hennessy points out, not the sanitized conservation history tourists consume, missing an opportunity to show how humanity is more deeply entwined with the nature that tourists have flown in to see.

By the late nineteenth century, conservation meant stockpiling dead specimens in museums of the global north. These centers of calculation erased the social relationships through which collectors found and extracted their specimens, yet they allowed scientists to refine evolutionary theory and to hone their knowledge of...