These perceptions of islands have also pervaded academic thought. In archeology and anthropology, island ecosystems have often been contrasted with their mainland counterparts as uncompromisingly sensitive to past human actions. Think of, for example, the biggest celebrity of tropical island extinctions, the dodo of Mauritius, which disappeared in the seventeenth century AD shortly after the first permanent European settlements were constructed on this Indian Ocean island. On the one hand, seafaring hunters have been seen as decimating any island animal life encountering our species for the first time. Without protective strategies, and with no hope of escape or reinforcements from distant shores, mammals, birds, amphibians, and reptiles could very quickly be erased from history. On the other hand, islands have been framed as inherently “resource poor,” with human societies only able to succeed by bringing new, domesticated plants and animals along for the ride. These same food producers faced further, if different, issues of sustainability, however. Limited island soils were prone to erosion and the loss of nutrients. Smaller forests, if not given time to regrow, could also rapidly disappear, leaving a barren outlook for settlers reliant on construction materials and firewood. Sedentary farming societies also often, intentionally or unintentionally, brought along hitchhikers, like dogs, pigs, and rodents, that wreaked their own havoc on local plants and animals. Ultimately, in both cases, tropical islands have been seen as particularly prone to forces of human “destruction.” The collapse of island environments, as well as their prehistoric human societies, must have been inevitable. After all, the increasingly expanding infrastructure, settlement, and profit-driven agricultural strategies of our own societies are unleashing irreversible changes on these habitats today.2
Nevertheless, if we want to properly study how past humans negotiated the colonization of uninhabited tropical islands, and if we want to determine the degree to which their increasingly intensive interaction with the natural world had impacts on island ecosystems, compared to human-driven changes seen in the twenty-first century, we need hard data. We also need to strip away our own value judgments of which activities and changes are inherently “good” and “bad.” Particularly, given what we have seen in Chapter 7, we need to take a step back from assumptions that all forms of “food production” look like the monotonous, tree-clearing agricultural fields and pastures we see today. Instead, we can investigate islands as places where people experimented with the introduction of new plant and animal species, alongside the foraging, fishing, hunting, and managing of the available natural resources. Focusing on some of the most classic of our island paradise fantasies, across the Caribbean, the Pacific, and the coastlines of Africa, we will now delve into the blossoming subfield of island archeology. We will see how archeobotany, zooarcheology, and modern and ancient genetic analyses are providing insights into how humans constructed new island “niches” for themselves, transporting landscapes, as well as domesticates, from mainland settings. We will accompany scientists working in some of the most remote regions on Earth to look at how environmental records of landscape change, from lakes, swamps, and archeological sites, can show the changing scale and intensity of the subsequent impacts of different practices on local or “endemic” island plants and animals, as well as the soils and forests these populations came to depend upon for cultivation and raw materials. Certainly, difficult situations arose, sometimes in settings many hundreds or even thousands of kilometers away from the next human population. Yet adaptable oversight and innovative combinations of local resource use and domesticated plants and animals could prove remarkably resilient in what have often been considered the most delicate of tropical environments. All it needed was some good old-fashioned on-the-ground understanding of local ecologies—something that Euro-American societies are often disturbingly lacking in today.3
WE START OUR island circuit in the Caribbean, a series of seven hundred islands well known for their tropical vegetation, spotless beaches, diverse Indigenous cultures, and film-famous buccaneers. Surrounded by the Caribbean Sea and North Atlantic Ocean, just east of North, Central, and South America, this region has been occupied by a variety of hunting and farming communities over the course of the last 8,000 years, providing ideal “laboratories” for observing how different human economies and forms of social organization can impact tropical islands. Professor Scott Fitzpatrick of the University of Oregon is well and truly an island archeologist and has had the “arduous” task of excavating in the Caribbean for much of his academic career. The envy of most of us, Scott has made his name exploring how oceangoing human societies colonized, adapted to, and impacted islands across a region many would pay handsomely to visit just once. “Beyond being a wonderful location to work, the Caribbean is ideally placed to test whether the combination of humans plus islands inescapably equals ecological catastrophe,” he says. This issue is particularly pressing for communities and governments across this part of the world given that deforestation, threats to unique plants and animals, and the degradation of coral reefs all run rampant in the twenty-first century. In fact, entire marine and land-based ecosystems are expected to disappear in many parts of the Caribbean within the next twenty years if action is not taken to curb pollution, global warming, overfishing, and tourism. Are these modern phenomena? Or can we perhaps learn from ancient precedents?4
The first human inhabitants of the Caribbean arrived via two different entry routes. The so-called Lithic group potentially came from Central America, arriving in the Greater Antilles (the northern chain, which includes Cuba and Hispaniola) by c. 6,000 to 5,000 years ago. The other, “Archaic” group moved from South America, arriving first in Trinidad 8,000 years ago before moving into parts of the Greater Antilles, the northern Lesser Antilles, and at least two islands in the southern Lesser Antilles, Barbados and Curaçao, between c. 6,000 and 3,000 years ago, and eventually expanding throughout the Caribbean. These groups were mixed hunter-gatherer-fishers, making tools from stone and, in the case of Archaic groups, relying heavily on coastal resources, as revealed by large mounds of human-accumulated shells (or “shell middens”) located on the coast, which likely sustained increasingly settled populations. While we are unsure of their population sizes, these Archaic populations certainly left their mark. An extensive survey of environmental cores obtained from wetlands and lakes across the southern and eastern Caribbean indicates that these groups were active horticulturalists that cleared forests, perhaps using fire from their earliest arrival in order to manage environmental variation, though this remains disputed. Certainly in Trinidad, a present-day island that would have been connected to the South American mainland during the early Holocene (11,700 to 8,200 years ago), the opening up of patches of forest aided the growth of South American domesticates, such as maize, sweet potato, and chili peppers, which have now been found at Archaic sites from as early as 7,700 to 6,000 years ago.5
These land-altering Archaic populations have been implicated in the extinction of native fauna in a region that has witnessed more Holocene (11,700 years ago to the present) mammal extinctions than any other. For example, the deliberate human burning of forest in Antigua may have stimulated the disappearance of three endemic small bat species from this island. Direct hunting of slow-reproducing large mammals, like native primates and the giant ground sloth, is also thought to have led to the extinction of species that had survived in the Caribbean well into the Holocene. Their disappearance, following Archaic arrival, certainly piques the interest of archeological investigators. Nevertheless, this remains debated, and there are few sites with clear evidence of hunting by these earliest settlers, with a combination of early Holocene climatic variability, human-induced habitat changes, and perhaps limited hunting more likely combining to bring these animals down in a more gradual manner. In fact, these early Caribbean populations were remarkably in tune with their new island environments. As well as domesticates, they moved well-suited native wild species between the different islands, including wild avocado, wild fig,
and rodents. They cleared forests, not just to make way for domesticates, but also to promote nutritionally useful native taxa such as wild plantain, yams, the starchy roots of maranguey, arrowroot, and the seeds of certain palm trees. On Puerto Rico they even seem to have modified soils to promote fertility by 3,000 years ago.6
The later “Ceramic” period of human expansion across the Caribbean seems to have brought an intensification of certain types of activities along with it. Beginning 2,500 years ago in Puerto Rico and the Lesser Antilles, prior to spreading out across the rest of the Greater Antilles by 1,500 years ago, this wave of Early Ceramic populations, with an apparent genetic link to human populations in the Amazon Basin, involved the ancestors of the Taíno Indigenous group of the Caribbean. As the name suggests, these populations introduced pottery to the region, although others have suggested it had already arrived with preceding Archaic groups. They also introduced dogs and guinea pigs across its islands and moved the agouti (a sort of long-legged guinea pig), peccary (a piglike mammal with hooves), opossums, and armadillos out into the Lesser Antilles. It was also during this wave of migration, archeobotanists can show, that South American crops truly took hold across the Caribbean, and maize, beans, manioc, peanuts, sweet potato, tobacco, chili peppers, and guava can be found across the islands, fueling the establishment of settlements that were increasingly distributed across island interiors as well as the shoreline, unlike their more coastal-focused Archaic predecessors. The extensive farming, clearance, and horticulture practiced by these Ceramic groups had visible impacts on Caribbean ecosystems. By the time Europeans arrived, Indigenous populations were cultivating nearly one hundred species of plants; they had cleared forest in many island areas, transformed hillsides with terraces, and formed mounds for growing manioc.7
Figure 8.1. Map of the Caribbean showing the main waves of human colonization of different islands, with dates (the arrows show routes of dispersal that would have required seafaring). The first human inhabitants of the Caribbean (“Archaic”) are thought to have arrived from South America, making it to Trinidad 8,000 years ago before reaching the Greater Antilles, the northern Lesser Antilles, and Barbados ~6,000 to 3,000 years ago. A later “Ceramic” period of human expansion from South America, which reached Puerto Rico and covered the entire Lesser Antilles, occurred around 2,500 years ago. Here, BP stands for “calibrated years Before Present” (the standard format for radiocarbon timescales). Scott Fitzpatrick
Unsurprisingly, this more intensive occupation and settlement would have significant impacts on local island ecosystems. In Puerto Rico and the Virgin Islands, exhaustion of local crab resources stimulated a switch to consumption of mollusks, which were in turn overharvested in Jamaica from 1,000 years ago. On the island of Puerto Rico, zooarcheologists have shown a reduction of fish body size and a decline in the length of reef food chains at Ceramic sites over time, which indicates overfishing. Evidence for the consumption of native amphibians, reptiles, seabirds, and rodents, often in unsustainable fashion, is also clear at a number of sites across the Lesser Antilles. These issues are visible in many parts of the Caribbean today, particularly in relation to the overuse of reefs and forest clearance for agriculture. Nonetheless, the degree to which Ceramic populations led to sweeping and permanent change remains unclear, especially as estimating their population sizes is difficult. Many small animals being used by these groups, such as now threatened tiny “hutias” and other mouse-like rodents, survived until after the arrival of European colonizers in the Caribbean. On the islands of Anguilla and Nevis, precolonial populations were sustainably, albeit intensively, harvesting marine mollusks. We will never know how the Ceramic populations would have continued to fare on their island homes. Indeed, it is only with the spread of disease and atrocities perpetrated by European colonizers, which resulted in mass mortality among the Indigenous populations, that we begin to see a clear and complete disruption of long-term human-environment interactions and the onset of profit-driven extraction of resources and labor that we will turn to in Chapter 10.8
IN CONTRAST TO the multiple waves of human cultures with different economies moving into the Caribbean, the human colonization of the Pacific Islands by people speaking languages within the Austronesian group has often been considered a more sweeping, classic example of a migrating human population with a uniform, introduced farming economy. Ancient DNA of human skeletons from the isolated Near Oceanian and Polynesian islands of Vanuatu and Tonga has shown that their earliest human occupants, buried with so-called Lapita pottery, descended from populations in East Asia. Moving from Taiwan, human populations, with this characteristic “dentate” style of pottery, reached the Philippines by approximately 4,000 years ago. True Lapita pottery, tempered from sand and shell, then appears on the Bismarck Archipelago by approximately 3,350 years ago before moving through the Solomon Islands, Vanuatu, and New Caledonia, reaching Fiji, Samoa, and Tonga by approximately 2,700 years ago. From that point there was something of a pause, with around 2,000 years passing before Polynesian descendants of these early populations went on to colonize Rapa Nui (Easter Island), Hawai’i, and Aotearoa (New Zealand). These expert seafarers navigated thousands of kilometers of open water, using sophisticated outrigger canoes like those made globally famous in recent times by Disney’s Moana. In many cases, they were the first human feet ashore, and what they brought with them could have major consequences for ecosystems, particularly on islands where there was no easy trip home and adventurous exploring groups could quickly become cut off.9
Despite its common association with the expansion of the Austronesian language groups across island Southeast Asia, there is no direct evidence for domesticated rice at any early Lapita site in the Pacific Islands. Instead, one of the main early domestic arrivals on these island outposts is an animal. Modern and ancient DNA evidence shows that domesticated pigs made the journey with Lapita-carrying populations out across the Pacific. When we see these animals rummaging around human settlements or farms, we do not often consider that they can actually have widespread environment-altering impacts. Today, feral pig populations on Pacific Islands reduce rare, native tropical plant biodiversity as a result of their indiscriminate foraging, and they encourage invasive species to take root by reducing local competition and dispersing seeds through their digestive tracts or by carrying them on their skin. The foraging and trampling of pigs can also increase soil erosion, and scientists have invoked pigs, which are immensely important to many Pacific Island cultures and economies today, as a cause of increasing landscape instability on many islands following the arrival of humans. Although without rice, these colonizing populations also carried horticultural “transported landscapes,” using fire to open forests and promote the growth of other introduced plant domesticates such as taro, yam, and banana. Deliberate deforestation for houses, canoes, pigpens, and other structures led to further landscape changes. On Tonga, Vanuatu, and the famous Rapa Nui with its haunting statues, tropical forest tree species declined in abundance following human colonization, further exacerbating soil erosion as root systems were dragged away. Zooarcheologists have also observed heavy human pressure placed on reef resources by these nautical maestros, particularly in later periods as settled populations expanded.10
The spread of Lapita pottery across the Pacific Islands also brought with it one of the most prominent examples of an island-altering ecological stowaway. The Pacific rat is commensal to humans, meaning that it can rapidly become entwined with human settlements, relying on human food and traveling closely with human groups where it is able. Archeological and genetic evidence shows that during the expansion of Austronesian-language-speaking populations, the Pacific rat was transported onto virtually every single island in the Pacific. The results were often game changing for island ecosystems. These rats were large, fast-breeding, omnivorous, and numerous, used to feeding off human scraps. Alongside direct hunting by humans, rats posed a major threat to land and sea birds given their particular fetish f
or the eggs of endemic birds. Unable to reproduce in safety and unused to such menace, as many as 2,000 species of bird went extinct following human occupation on tropical Pacific Islands. These feasting rodents may also have driven the extinction of native terrestrial snails and insects. Rats, gnawing on seeds and nuts, have also been implicated in declines of local plant communities, including the reductions in forest cover witnessed on Rapa Nui. As this latter example has often been used to show, intended and unintended human introductions to Pacific Island ecosystems could together lead to the rapid transformation of island forests into landscapes with no trees, reduced diversity of land-based wildlife, slipping soils that posed obstacles to food production, and declining fish and shellfish. On islands separated from other landfall by as much as 2,000 kilometers, human population collapse could become all but guaranteed.11
Although this dramatic “doomsday” scenario sells books, it also glosses over a number of instances in which arriving farmers and horticulturalists tuned their strategies to their new island homes. Dr. Monica Tromp of the University of Otago has applied the latest scientific methodologies to human remains from the island of Vanuatu to revolutionize our understanding of the diets of some of the earliest Lapita producers. As we have seen, human colonization of much of the Pacific is often characterized as involving a complete overhaul of island ecosystems. “However, by studying microscopic remains of plants trapped in the gunk between ancient peoples’ teeth we gain another perspective on the region’s earliest settlers,” says Monica. Instead of domesticated plants, Monica found that the vast number of preserved plant particles in this ancient tartar came from wild rainforest trees. This is direct evidence that tropical forests not only supplemented but often also dominated the diets of the first settlers of Vanuatu. While cultivated crops were also introduced, Lapita-carrying seafarers knew the value of tending to the existing wild resources. This story is not unique to Vanuatu, and the microscopic remains of rainforest trees have also been documented at Lapita sites elsewhere in Near Oceania as well as Micronesia. Indeed, many signals of “clearance” and burning may also indicate the promotion of local useful plants, as much as incoming domesticated crops and animals, as populations shaped local forests to their liking. Elsewhere, the use of wild animals such as fruit bats, turtles, cuscuses, rodents, lizards, frogs, snakes, and crocodiles, some (albeit relatively few) of which survive to this day, has also been documented. Meanwhile, zooarchaeological evidence for the successful, diverse use of marine resources, from different ocean habitats, has provided a more sustainable, island-specific insight into fishing practices.12
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