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Islands – the Last Frontier?. LLM 3, 2019, davis@geog.utoronto.ca. Anish Kapoor’s representation of what’s happening in the UK. Titled ‘A Brexit, A Brexit, We All Fall Down’. Caribbean tectonics. Earthquakes in eastern Canada.
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Islands – the Last Frontier? • LLM 3, 2019, davis@geog.utoronto.ca
Anish Kapoor’s representation of what’s happening in the UK. Titled ‘A Brexit, A Brexit, We All Fall Down’
Small white flowers in NZ flora. Tea tree –Manuka- (left). NZ holly (below left). Lacebark (below right).
Kaka beak (left), Kowhai (bottom left) Pohutukawa (centre and bottom right).
Homo luzonensis – a new human species ? Very small hominid (1.3 m). Around 60,000 years old. Few remains. All small. A regional addition to tiny H. floresiensis? Another case of nanism?
Remote islands have been the last places for human settlement. Hawaii was settled only 1500 years ago, New Zealand only 700 BP. Even Iceland, not generally considered remote, was not colonized until 870 AD. • The human diaspora begins with the movement of people out of Africa. There appear to have been two pulses. The first by Homo erectus nearly 2 million years ago. The second by Homo sapiens perhaps as early as 200,000 years ago.
Recent finds indicate that the pattern was much more complicated than originally proposed, and probably much earlier.
The movement of modern humans came at another time of climatic change. People moved into areas that seem to have been unsuited to tropical primates. Why and how could they do this?
Impetus – why move? • Increasing technological and cultural sophistication. • The availability of routeways.
Human development; • 1. bipedal, upright stance • 2. increased mobility • 3. increased size and brain capacity • 4. development of a increasingly sophisticated tool technology • 5. use of fire
During glacial maxima sea level was 120 m below present levels.
Out of Africa via the Arabian Peninsula and the Persian Gulf
Northwestern Europe at full glacial. The northern half of the left hand map would have been ice covered as would most of the British Isles and the North Sea.
Across the Pacific • The Pacific was settled from the Malaysian archipelago, probably in a series of pulses. The many islands of the western an central Pacific are grouped into Micronesia,Melanesia and Polynesia. We’ll focus on the latter. Settlement of the central Pacific began about 3500 BP (Samoa and Tonga). Hawaii was not settled until 1500BP and New Zealand less than 1000 years ago.
Why did it take so long? Two basic skills were necessary – the construction of seaworthy boats and a reliable navigation system and some incentive.
They took with them various plants and animals. The main plants were mostly tropical - taro, sweet potato, bananas, noni, kava, sugar cane, breadfruit and paper mulberry (used to make tapa cloth). Animalsincluded dogs, pigs, chickens and the kiore. • This package is sometimes referred to as a ‘transported landscape.’
Breadfruit (below), otaheite apple (right), Tahitian chestnut (bottom right)
Successful settlement and long-term survival required the development of a productive, sustainable agriculture to replace the traditional shifting agriculture of the western Pacific. This combined irrigated fields for taro and other crops, fish ponds and arboriculture. Although this system worked well, there were serious environmental consequences.
We now know that over 50 % of the species of Hawaiian endemic birds became extinct soon after settlement. A similar period of extinction followed Maori settlement of New Zealand. • In both cases, the extinctions were caused by over-exploitation, the removal of natural habitat and the introduction of alien species.
A similar situation happened in New Guinea to birds of paradise • .
The Maori and the demise of New Zealand’s native birds • In New Zealand, the arrival of the Maori about 800 years ago was marked by forest clearance and the extinction of many bird species including 11 species of moa. Some of these birds were up to 3.7 m tall and weighed as much as 230 kg.
Haast’s eagle (Harpagornismoorei) – island gigantism. Extinction coincident with the demise of the moa.
About 2/3 of New Zealand’s native birds have gone extinct since the arrival of the Maori and settlement from Great Britain and Australia from the 1790s. • Why were these birds so susceptible? • In all of the anguish there are some unlikely success stories. In 1980, there were only five Chatham Island black robins left, and only a single breeding pair. At last count there are about 250, but these numbers are still perilously low.
Although most island colonizations appear to have been successful, there are some notable exceptions. The best known of these is the demise of the Polynesian society on Rapa Nui (Easter Island).
Rapa Nui is a small (25x15 km) volcanic island, at 27S latitude, isolated by about 2000 km from other south Pacific islands. • Its most distinctive features are the hundreds of carved heads (moai) that dot the landscape. It was one of the last Pacific islands to be colonized.Its demise has been termed ‘ecocide’.
It is likely that Polynesians arrived in Rapa Nui before 900 AD. From that first arrival population expanded to as many as 30,000 by 1500 AD. By 1722 AD, when Europeans found the island, that had fallen to about 1000. • So what caused this decline? • The inherent limitations of the island. It was isolated, low, small, dry and had a relatively high latitude. How do these impact?
