Saturday, 20 June 2009

Human Evolution On Trial - 'Eastern Polynesia'

Human Evolution On Trial - Eastern Polynesia

The New Zealand Maori language is classified as part of the Eastern Polynesian group. Eastern Polynesian languages are spoken on most islands across the central Pacific, from Hawai‘i in the north, Easter Island in the southeast to New Zealand in the southwest (map 3). All the languages within the triangle are quite closely related and have probably diversified only in the last 1500 years or so. The defence claims we can use the Polynesians’ expansion into this previously uninhabited region of the earth to explain several ancient examples of human migration, and our evolution.

The Polynesian group, as a whole, includes Western Polynesian: Tongan, Samoan and some other related languages, both nearby and far to the west. The Far Western Polynesian languages are called the “Polynesian Outliers”. These are generally accepted as the product of movement west from the central Pacific. The Polynesian Outliers are scattered through parts of Eastern Melanesia: New Caledonia, Vanuatu and the Southern Solomon Islands. Most of the Melanesian languages are not Polynesian although many are related to it. We’ll come back to this next in “Polynesian Origins” [Language Families].

Fiji lies on the boundary between Polynesia and Melanesia. Some linguists consider the Fijian languages to be the closest to ancestral, or proto, Polynesian (Jennings 1979). We’ll come back to how the Polynesians’ ancestors reached Fiji in “Pacific Population” [Lapita]. It is difficult to know whether Samoa or Tonga were the first islands settled after Fiji. Both groups share with Fiji quite a common cultural heritage, and quite a movement from Tonga back to Fiji occurred even in historic times (Howe 1984). In Polynesian languages “Tonga” means “south”, “Tokelau” (tokerau in Maori) means “north”, “Tongareva” (rewa) may mean “float south”, “Tahiti” (tawhiti) means “distant” and “Tuamotu” may mean “islands beyond”. The defence suggests these names are significant for the study of Eastern Polynesia’s settlement.

Polynesian Languages

Comparison of language relationships, cultural variation and physical similarities produce the following diagram (Houghton 1980, and Jennings 1979). The dotted lines enclose the cultural groupings within Polynesia. Apart from New Zealand and the Chatham Islands, which are actually south of Fiji, the islands are in about their geographic positions (see map 3). The names by which the cultural groups are known appear in Italics and are underlined. The solid lines show language connections, the numbers the presumed place of development of language types.

Polynesian Evolutionary Tree

The place of branching for 1, 2, 3 and 4 is fairly obviously in the stretch of islands between Tonga and Tokelau: South and North. Interestingly the island of Western Samoa is actually called Savai‘i, the same word in their dialect as the Maori place of origin: Hawaiki. Some of the languages spoken through the Northern Cook Islands, part of the Intermediate region, may branch off in the gap between proto-Nuclear Polynesian and proto-Central East Polynesian (Jennings 1979), which makes sense.

The earliest adzes in the Marquesas Islands resemble ones of the same age (about 2000 years) on Samoa (Bellwood 1978) and so it is generally accepted the people of Eastern Polynesia came from near Samoa. But the order in which the islands were settled and the place of development of the distinctive Eastern Polynesian culture are disputed. There are difficulties in accepting as candidates for the development of this culture any of the relatively large islands such as Hawai‘i, the Marquesas Islands, or Tahiti in the Society Islands.

A dispersal centre for Eastern Polynesians at 5 would eliminate all the contradictions (such as unexplainable patterns of change in culture and fishhook styles) introduced by placing it at any island group actually named in the diagram. Number 5 covers the islands of Tongareva, Rakahanga, Manihiki, Pukapuka and the Phoenix and Line Islands. Many of these small islands were uninhabited when Europeans first reached them but most showed signs of having been inhabited at some time. None are large enough on their own to be a centre for the development of Polynesian culture. But I would like to suggest each single coral atoll could have supported a large population for two or three generations, by which time another island would have been discovered and off they would all go again. I understand dog remains have been found in the Northern Cook Islands dated to about the right time to support the idea of this migration route.


McGlone et al (in Sutton 1994) call finding previously unoccupied islands the prehistoric equivalent of winning a lottery. With huge populations of birds and animals with no fear of humans, and undisturbed fish and shellfish in the surrounding sea, there would have been no shortage of food for these first arrivals. The huge populations of foraging seabirds would also have made unoccupied islands effectively bigger targets and easier to find than they would be today. Any volcanic islands would be sources of stone for tools, implying a great deal of deliberate two way voyaging. The whole process provides easily enough time for the culture to diverge from Samoan and become recognisably different and diversified by the time the Marquesas, Society (Tahiti) and Hawai‘ian islands were settled. In Part IV the defence will suggest that several early human expansions through open grassland containing scattered clumps of trees were similar.

The defence will later show that the pattern of animal “Extinctions” [What Have We Done?] can be used to date human expansion. But the lack of evidence of extinctions in the Pacific islands, apart from New Zealand (“Change” [Destruction]), is more a result of a lack of research than that it didn’t happen. There is evidence of extinctions in New Caledonia, Hawai‘i and Fiji but these are the only islands where such study has been done. Even then only Hawai‘i and New Caledonia have been well studied and they show many extinctions occurring at the expected time. The Polynesian rat also gets to all the islands at the expected time with an apparently early date for New Zealand. People were just beginning to move beyond Western Polynesia at the time the rat appeared in New Zealand (some time between 300 BC and 300 AD). You saw in “Change” [Destruction] there is also evidence of man-induced fires in the eastern North Island this early (Elliot, Manighetti and Carter, 2003).

The ancestors of the Maori didn’t actually arrive in New Zealand and the Chatham Islands direct from the Northern Cook Islands, or the area of number 5. Of course my diagram is a bit simplified. There is quite a bit of evidence, such as the types of stone tools found in each region dating to the appropriate time, that the first settlers actually came to New Zealand mainly via the Southern Cook and Austral Islands (Sutton 1994). The recent arrival in New Zealand of people from Tonga and Samoa represents the opening of a new migration route. There is really no evidence any migration direct from that region contributed to the prehistoric population of New Zealand, but it is not impossible.

David Tuggle (Jennings 1979) postulates the settlement pattern for Hawai‘i was the same as that suggested by James Belich (1996) for New Zealand: a dispersal of people around the most easily exploitable regions at the first colonisation (“Change” [Destruction]). Population growth eventually pushed people into less desirable locations. This was probably the pattern on all the islands and certainly seems so on the Marquesas (Howe 1984). All human migrations into uninhabited regions, including very ancient ones (see “The First Point” [Homo habilis]), have probably been similar. The rapidly advancing wave lives off the easy pickings. People left behind, or coming in following waves, have to adjust to fewer resources. Sometimes those left behind have even become extinct and disappeared entirely.

I believe it may have been during the first stage of movement into the Pacific Ocean beyond Western Polynesia that the legends of the hero Maui fishing up islands (discovering them?) developed. More islands kept appearing ahead of the migration wave and, by human assumptions or Chinese drover’s clever dog syndrome, someone must have made them or brought them up. It was handy if, in the future, you could claim your ancestors had been on the island when Maui fished it up though.

Study of the distribution of Polynesian myths could be revealing. For example it would be interesting to know if the name Kupe is confined to New Zealand. We do know the islands of the Marquesas and Mangareva have a similar hero named Tupa (Orbell quoted by McGlone et al in Sutton 1994). Therefore Kupe is possibly a general name for an explorer; in other words any great sailor was given the name “Kupe.” So Kupe could represent a string of people given the same name because they had the same attributes, as probably does Maui. The defence will suggest some other examples from oral tradition in “Culture” [Evolution of a Religion].

Marginal Polynesia

Loss of genetic variation during their evolution means Polynesians from the many different islands are remarkably similar to each other. I met native Hawai‘ians in a bar in Arkansas, USA. The Hawai‘ians looked exactly like New Zealand Maori. In fact when I first entered the bar I thought, for a while, I’d been magically transported to some bar in New Zealand.

The Polynesians are known as a large-framed people (Houghton 1980). This large frame is an unusual characteristic for both tropical and island populations. Generally speaking creatures in tropical regions tend to be smaller, or at least thinner, than are their relations in cooler areas. This is called “Bergmann’s rule” (Stringer and Gamble 1993). We saw in “Hybrid Vigour and Inbreeding” [Survival] it is also a general rule that creatures that are large on a mainland tend to be smaller on islands (Malcolm Browne in Wade 2001). The most likely explanation for the unexpected Polynesian physical type is that cold, wet nights, especially those spent at sea during migrations or fishing expeditions, would favour the survival of individuals with a larger body mass (Howe 2003). Smaller people lose heat much more rapidly and would suffer hypothermia. Movement between islands within Polynesia also offset the usual tendency for creatures on islands to become smaller. In other words the populations were not actually confined to single small islands. This would also help counter inbreeding.

Physical features of the people of each island group are closest to those of their nearest neighbours. This means there is basically a gradient of variation from the widespread islands of marginal Polynesia all the way back to Western Melanesia, a cline. Even where it is obvious there has been a movement back into Melanesia by Polynesian-speaking people originating from the area within the above diagram (Howe 1984) the cline is maintained. These people have now become genetically mixed with their neighbours (Melanesian people) but maintain their Polynesian language (the Polynesian Outliers).

But at the eastern end of the cline populations of the various widespread groups of islands are more similar to each other than they are to their nearest neighbours in the Central region. This doesn’t prove movement around the edge but suggests the lines in the diagram don’t represent single migrations. Kazumichi Katayama (Sutton 1994) shows that people from the Southern Cook Islands are as similar to Samoans as they are to New Zealanders. This indicates there were a series of genetic movements or waves along the old routes. In fact both genetic and linguistic evidence supports the idea of a series of movements along the lines.

Tracing changes in the languages shows the marginal area generally preserves older versions of the ancestral language but innovations in the Central area have spread unevenly into the marginal regions. In fact the innovations appear not to have reached Easter Island at all. That language preserved elements of Western Polynesian languages (Bahn and Flenley 1992). In “Indo-Europeans” [Celtic] you will see a similar thing happened with the Celtic languages. Ray Harlow in Sutton (1994) suggests regional dialects spoken in New Zealand may reflect changes in the dialects spoken in the Central islands. In other words there were several movements into New Zealand from several places but probably over a short period, say 200 years at most. During the remainder of this case the defence will present many examples of linguistic, genetic, technological and even religious innovations in a central area failing to reach the margins.

Easter Island

To finish this look at Eastern Polynesia we’ll take a quick look at the extreme eastern margin of their distribution, Easter Island. It provides excellent evidence for interpreting the whole pattern of human expansion around the world. But the jury will see the Polynesians are basically part of a cline stretching all the way to Indonesians, Filipinos and Malays.

Genetic evidence shows the first people on Easter Island were from Central East Polynesia (Lewin 1999) and physical appearance, language, culture and technology all support this. They arrived on an island reasonably well forested with Sophora trees (called kowhai in New Zealand), palms and several other kinds of tree. Archaeology reveals the first settlers used the wood for canoes and dined magnificently on deep-sea fish, dolphins and turtles, as well as nesting seabirds. But by the time Europeans first saw the island no sizable trees remained and the people were no longer able to make canoes and to fish at sea (Bahn and Flenley 1992). The trees had been cleared for firewood and cultivation, and the rats Polynesians had brought with them prevented regeneration because they ate any seeds. The seabirds had also died out (Diamond 2005).

Increasing Population + Diminishing Resources = Strife + Selection

In myth the population had become divided into two warring groups: “Long Ears” and “Short Ears”. There is no evidence these groups had a separate origin other than possibly being a previous “upper class” and a “lower class” (Roberts 1989). The resulting strife, and selection, was not nice. The jury will see that, far from being the centre of a magnificent Pan-Pacific prehistoric culture as claimed by some people, they represented the last, doomed and impoverished remnant of a population movement that had come one third of the way round the earth after leaving Taiwan more than 5000 years before. The defence now needs to explain how we know they came from Taiwan.

See next :: Human Evolution on Trial - 'Polynesian Origins'

Update 10th November 2008:

See also :: : "The first expedition following the migration route of the early Polynesians"

(Start: November 2008, Arrival: April 2009)

Witnesses Called

Bahn, Paul and Flenley, John (1992) Easter Island, Earth Island. Thames and Hudson, London

Belich, James (1996) Making People. Penguin Press, Auckland.

Bellwood, Peter (1978) Man’s Conquest of the Pacific. Collins, Auckland.

Diamond, Jared (2005) Collapse. Penguin Books, London.

Elliot, M., Manighetti, B. and Carter, L. (2003) Dating the Human Colonisation of New Zealand. Proceedings of the New Zealand Geographical Society.

Houghton, Phillip (1980) The First New Zealanders. Hodder and Stroughton, Auckland.

Howe, K. R. (1984) Where the Waves Fall. George Allen and Unwin, Australia.

Howe, K. R. (2003) The Quest for Origins. Penguin, New Zealand

Jennings, Jesse D. (1979) The Prehistory of Polynesia. Australian National University

Press, Canberra.

Lewin, Roger (1999) Patterns in Evolution. Scientific American Library, New York.

Roberts, Neil (1989) The Holocene. Basil Blackwell, Oxford.

Stringer, Christopher and Gamble, Clive (1993) In Search of the Neanderthals. Thames & Hudson, Great Britain.

Sutton, Douglas G. ed. (1994) The Origins of the First New Zealanders. Auckland University Press, New Zealand.

Tyson, Peter (2008) Gigantism And Dwarfism On Islands, Nova

Wade, Nicholas ed. (2001) The New York Times Book of Fossils and Evolution. The Lyon Press, New York.

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