Ancestral Polynesians who were driven to explore the open ocean with their sophisticated navigation and large canoes (as we saw in chapter 2) may have created selection pressures on genes that better equipped their bodies to cope with periods of starvation or cold while at sea. Their journeys likely imposed selection for more efficient handling of the energy needs of the body via what are sometimes termed thrifty genes. Plus, living on islands - despite people's romantic fantasies - is extremely harsh because adverse weather (like hurricanes) can wipe out all of the available food for substantial periods, which imposes a set of constraints similar to long sea voyages. Adaptive though they were for the long journeys and isolated living centuries ago, these genetic changes are a prescription for diabetes and obesity today, now that the descendants of those Polynesians have built settlements on land and obtain sources of food that are more stable. (Blueprint: The Evolutionary Origins of a Good Society)
It is hypothetically possible that for example the Samoan population has not has such strong recent selection of these traits, and therefore would be more susceptible to obesity following introduction of modern high-calorie foods.
I'LL EXCERPT THE MOST PERTINENT PARAGRAPHS FROM THE BELOW ARTICLES THEN ADD THOSE PARAGRAPHS AND ARTICLES TO THE ABOVE LINK! I'LL DO THIS LATER THIS WEEK! IN THE MEANTIME, READ ABOUT THE THIRFTY GENE HYPOTHESIS AND HOW IT INFLUENCES POLYNESIAN PHYSIOLOGY (e.g. FAT STORAGE) IN TODAY'S FOOD ABUNDANT ENVIRONMENT.
In New Zealand, Ian Prior, a young cardiologist who would later become the nation's most renowned epidemiologist studied a population of five hundred Maoris living in an isolated valley of the North Island thirty-five miles from the nearest town. Despite a physically active life - certainly by the standards of modern-day Europe or the United States - the Maoris, as Prior reported in 1964, had a remarkably high incidence of diabetes, heart disease, obesity, and gout. Sixty percent of the middle-aged women were overweight; over a third were obese. Sixteen percent had heart disease, and 11 percent had diabetes. The staples of the Māori diet, Prior reported, were bread, flour, biscuits, breakfast cereals, sugar (over seventy pounds per person a year), and potatoes. There was also "beer, ice-cream, soft drinks, and sweets." Tea was the common beverage, "taken with large amounts of sugar by the majority."
....
After the United States exploration expedition under Captain Charles Wilkes visited the Polynesian atolls of Tokelau in January 1841, the expedition's scientists reported finding no evidence of cultivation on the atolls and confessed their surprise that the islanders could thrive on a diet composed primarily of coconuts and fish. Tokelau came under the administration of New Zealand in the mid-1920s, but the atolls remained isolated, visited only by occasional trading ships from Samoa, three hundred miles to the north. As a result, Tokelau lingered on the fringes of Western influence. The staples of the diet remained coconuts, fish, and a starchy melon known as breadfruit (introduced in the late nineteenth century) well into the 1970s. More than 70 percent of the calories in the Tokelau diet came from coconut; more than 50 percent came from fat, and 90 percent of that was saturated.
By the mid-1960s, the population of Tokelau had grown to almost two thousand and the New Zealand government, concerned about the threat of overpopulation, initiated a voluntary migration program during which more than half the Tokelauans moved to the mainland. From 1968 to 1982, a team of New Zealand anthropologists, physicians, and epidemiologists led by Ian Prior took the opportunity to study the health and diet of the emigrants as they resettled, as well as those who remained behind on the islands as their diets were progressively Westernized. This Tokelau Island Migration Study (TMS) was a remarkably complete survey of the health and diet of all men, women, and children of Tokelauan ancestry. It was also quite likely the most comprehensive migration study ever carried out in the history of nutrition-and-chronic-disease research.
On Tokelau, the primary changes during the course of the study came in the mid-1970s, with the establishment of a cash economy and trading posts on the atolls. The year-round availability of imported foods led to a decrease in coconut consumption to roughly half of all calories. This was offset by a sevenfold increase in sugar consumption* and a nearly sixfold increase in flour consumed - from twelve pounds per person annually to seventy pounds. The islanders also began eating canned meats and frozen foods, which they stored in freezers donated by the United Nations; by 1980, six pounds of mutton per capita, three pounds of chicken backs, and five pounds of tinned corned beef had been consumed. (In comparison, 270 pounds of fish were caught per islander in 1981.) By then, the trading ships were also delivering annually some eighteen pounds per person of crackers, biscuits, and Twisties, a cheese-flavored corn snack. Smoking increased dramatically, as did alcohol consumption.
Through the 1960s, the only noteworthy health problems on the island had been skin diseases, asthma, and infectious diseases such as chicken pox, measles, and leprosy. (Modern medical services and a trained physician had been available in Tokelau since 1917.) In the decades that followed, diabetes, hypertension, heart disease, gout, and cancer appeared. This coincided with a decrease in cholesterol levels, consistent with the decrease in saturated-fat consumption. Average weights increased by twenty to thirty pounds in men and women. A similar, albeit smaller, trend was seen in Tokelauan Children. The only conspicuous departure from these trends was in 1979, when the chartered passenger-and-cargo ship Cenpac Rounder ran aground and the islanders went five months without a food or fuel delivery. "There was no sugar, flour, tobacco, and starch foods," reported the New Zealand Herald, and the atoll hospitals reported a shortage of business during the enforced isolation. It was reported that the Tokelauans had been very healthy during that time and had returned to the pre-European diet of coconut and fish. Many people lost weight and felt very much better including some of the diabetics.
As for the migrants to New Zealand, the move brought "immediate and extensive changes" in diet: bread and potatoes replaced breadfruit, meat replaced fish, and coconuts virtually vanished from the diet. Fat and saturated-fat consumption dropped, to be replaced once again by carbohydrates, "the difference being due to the big increase in sucrose consumption." This coincided with an almost immediate increase in weight and blood pressure, and a decrease in cholesterol levels - all more pronounced than the increases witnessed on Tokelau. Hypertension was twice as common among the migrants as among the Tokelauans who remained on the islands. The migrants also had an "exceptionally high incidence" of "diabetes, gout, and osteoarthritis, as well as hypertension." Electrocardiographic evidence suggested that the "migrants were at higher risk for coronary heart disease than were non-migrants."
A number of factors combined to make this higher disease incidence among the migrants difficult to explain. For one thing, the Tokelauans who emigrated smoked fewer cigarettes than those who remained on the atolls, so tobacco was unlikely to explain this pattern of disease. The migrants tended to be younger, too, which should have led to the appearance of less chronic disease on the mainland. And though the weights of the Tokelauan migrants were "substantially higher" than those of the atoll-dwellers and, "in fact, obesity became a problem for some," the migrant lifestyle was definitively the more rigorous of the two. The men worked in the forest service and casting shops of the railway; the women worked in electrical- assembly plants or clothing factories, or they cleaned the offices during the evening hours, and they walked "some distance to and from the shops with their purchases." Finally, the original Tokelauan diet had been remarkably high in fat and saturated fat, but the migrants consumed considerably less of both. If Key's hypothesis was correct, the migrants should have manifested less evidence of heart disease, not more.
In fact, the migrant experience had led to an increased incidence over the entire spectrum of chronic diseases. Prior and his colleagues acknowledged that their data made this difficult to explain in any simple manner. They suggested "that a different set of relevant variables might account for observed differences in incidence." Excess weight, whatever the cause, could explain at least part of the increased incidence of hypertension, diabetes, coronary heart disease, and gout among the migrants. They appeared to get more salt in their diets than the islanders did, so that might also explain the increased incidence of hypertension, as might the stress of assimilating to a new culture. The red meat consumed on the mainland might have contributed to the increased incidence of gout as well. The greater incidence of asthma could be explained by the presence of allergens in New Zealand that were absent in Tokelau.
*According To Records From The Local Trading Ships, This Increase Was Nearly Tenfold Between 1961 And 1980: From Seven Pounds Per Person Per Year To Sixty-Nine Pounds.
Good Calories, Bad Calories: Challenging The Conventional Wisdom On Diet, Weight Control, And Disease. Taubes, p. 108-109, 136-139.
The Great Stone Age Extinctions
The devastation wrought by our indigenous and traditional ancestors as they extinguished their way across the planet during and after the last ice age is only now becoming clear. Coincident with the first certain arrival of people in North America, I I,500 years ago, seventy-three per cent of the large mammal genera quickly died out. Gone were giant bison, wild horse, short-faced bear, mammoth, mastodon, saber-toothed cat, giant ground sloth and wild camel. By 8,000 years ago, eighty per cent of the large mammal genera in South America were also extinct - giant sloths, giant armadillos, giant guanacos, giant capybaras, anteaters the size of horses.
This is known as the Pleistocene overkill. Sentimentalists among us still try to insist that it was a changing climate, not mankind, that did the damage, or that we only delivered the coup de grace to species that were already in decline. It is remarkable how strong remains the wishful thinking for finding an excuse to believe in climatic change. But the sheer coincidence of the extinctions with the arrival of the first people, together with the fact that climate had often changed before as ice ages began and ended, and the strange selectivity of the extinguishing force - always killing the bigger animals - indict our species. There is also direct evidence: butchered carcasses with the spearheads of the Clovis people embedded in the bones. It is true that Africa and Eurasia saw no such sudden bursts of extinction of large mammals, and that mammoth hunting persisted for 2.0,000 years in Eurasia - but the mammoths and woolly rhinos went just as extinct there in the end as they did in North America. Besides, having lived with the human predator for millions of years already, the African and Eurasian fauna had already adjusted. The more vulnerable species had probably already died out, and the survivors had learnt to give us a wide berth, or to migrate in large herds. It is noticeable that the large North American mammals that did not go extinct in the Pleistocene overkill were mostly the ones that had crossed the land bridge from Asia together with people: the moose, elk, caribou, musk ox and brown bear. 'Did the animals simply fade away, or did we kill them?' asks Colin Tudge in The Day Before Yesterday; he answers his own question: 'Of course we killed them.'
In other parts of the world, where people arrived suddenly and recently, the ecological effects of them were devastating - irrespective of climate. The guilt of the human species is not in doubt. Take Madagascar, where at least seventeen species of lemurs (all the diurnal ones larger than ten kilograms in weight, one as big as a gorilla), and the remarkable elephant birds - the biggest of which weighed 1,000 pounds - were dead within a few centuries of the island's first colonization by people in about 500 AD. It was a process repeated throughout the Pacific by the Polynesians and most spectacularly of all just six hundred years ago on New Zealand, where the first Maoris sat down and ate their way through all twelve species of the giant moa birds (the biggest weighing a quarter of a ton) before turning cannibal in desperation. At one moa butchering site near Otago at least 30,000 were killed in a short time - and on average a third of the meat was left to rot, only the best haunches being taken. Entire ovens, with the roast haunches still in them, were left unopened, so abundant was the supply of meat. It was not just moas. Half of all New Zealand's indigenous land birds are extinct.
On Hawaii, we now know that there were about 100 species of unique Hawaiian birds, many of them large and flightless. Then, about 300 AD, a large mammal called humankind arrived. Within a short time no fewer than half of the Hawaiian birds were extinct. When this was first realized, after the excavation of an archaeological site in 1982, it was considered by native Hawaiians a major embarrassment for they had been arguing for many years that it was the arrival of Captain Cook that had upset a harmonious relationship between people and nature in the islands. In all, as the Polynesians colonized the Pacific, they extinguished twenty percent of all the bird species on Earth.
Begin watching at 23:10. Then continue watching at 34:41. Natives, this is what your ancestors did to native species (terminated them and exterminated them).
35:49, 37:40. Where and why the Haka originated.
27:45. Natives, this is your ancestral cuisine.
It took a little longer to wipe out Australia's large mammals. Yet soon after the arrival of the first people in Australia, possibly 60,000 years ago, a whole guild of large beasts vanished - marsupial rhinos, giant diprotodons, tree fellers, marsupial lions, five kinds of giant wombat, seven kinds of short-faced kangaroos, eight kinds of giant kangaroo, a two-hundred-kilogram flightless bird. Even the kangaroo species that survived shrank dramatically in size, a classic evolutionary response to heavy predation (which puts pressure on prey to start breeding when smaller). It is crucial to remember that the fauna of the Americas, of Australia and of oceanic islands was naive and unafraid of people. This, if anything, would have made conservation easier if the people had been so minded. Domestication or semi-domestication would have been simple. Consider this description of Lord Howe Island's virgin fauna when the first people reached it. In this case, unusually, the first people were sea-faring Europeans, the Polynesians having failed to find the island.
There was, wrote a member of the ship's party, ' ... A curious brown bird abt. the size of a Landrail in England walking totally fearless & unconcern'd in all part around us, so we had nothing more to do than to stand still a minute or two & knock as many as we pleased wt. a short stick - if you throwed at them and missed them, or even hit them without killing them, they never made the least attempt to fly away ... The Pidgeons were also as tame as those already described & wd. sit upon the branches of trees till you might go and take them off with your hand .. .', Imagine a whole continent full of large mammals like that.
Yet our ancestors did not domesticate or manage the tame mammoths of North America or the trusting giant sloths of South America. They butchered them into oblivion. At Olsen-Chubbock, the site of ancient bison massacres in Colorado, where people regularly stampeded herds over a cliff, the animals lay in such heaps after a successful stampede that only the ones on top were butchered, and only the best joints were taken from them. Some conservationists!
p. 217-220
