Volume 106 1997 > Volume 106, No. 2 > Shorter communication: A biological review of the prehistoric Rapanui, by Patrick M. Chapman, p 161-174
A BIOLOGICAL REVIEW OF THE PREHISTORIC RAPANUI
There is a wide range of speculation on alternative biological origins of the Rapanui (the native inhabitants of Easter Island), with recent publications giving new life to old hypotheses and debates. In addition to recent articles by Bahn (1994), Bahn and Flenley (1994, 1995), Finney (1994), Gill (1994), Hagelberg (1995) and Langdon (1994a&b, 1995a-d), there is the report on the Anakena excavation by Skjølsvold (1994) and a comprehensive survey of Easter Island ahu (ceremonial platforms) by Martinsson-Wallin (1994), both of which provide important information regarding the settlement of Easter Island. In this article, I review the biological data used in the various settlement hypotheses posed in the recent studies, examining oral accounts from the earliest European visitors, genetic data and osteological data.
Researchers are in agreement that the population encountered by Jacob Roggeveen on Easter Island in 1722 was of Polynesian origin. Many also believe that Polynesians were the first, if not the only, peoples to have arrived on Easter Island before 1722, possibly around A.D. 400. Heyerdahl (1989) is the most notable exception, arguing for initial colonisation of Easter Island from South America with a later Polynesian influx. However, there is little agreement regarding the origin of the Rapanui population. Current arguments by Bellwood (1978), Bierbach and Cain (1988), Gill (1994), Gill and Owsley (1993), and the Orliacs (1988) focus on the Marquesas. Other scholars, such as Bodin (1982), Finney (1993), Green (1993), Irwin (1992), Langdon (1994a&b, 1995a-d), Martinsson-Wallin (1994) and Van Tilburg (1994), suggest different islands in the Gambier, Tuamotu, southern Cook or Austral groups.
While Heyerdahl's arguments for the presence of South American Indians on Easter Island in early prehistory are heavily criticised, many researchers do admit the likelihood of prehistoric Polynesian contact with South America (Bellwood 1989, Irwin 1990 and 1992, McCoy 1979, Orliac and Orliac 1988). However, actual details of this hypothesised contact are lacking, with the exception of the transferral of the sweet potato (Bahn and Flenley 1992, Brand 1971, Yen 1974). Irwin (1990, 1992) suggests that contact is the result of a Polynesian voyage to South America, while Finney (1985) suggests that the simplest explanation for the presence of the sweet potato in the Pacific is a voyage by South American Indians into Polynesia.- 162
EARLY EUROPEAN ACCOUNTS OF THE RAPANUI
Many of the European explorers who visited Easter Island recorded observations on the Rapanui's physical appearance. Langdon (1993, 1994a&b, 1995a-d) has used these observations as evidence in support of his hypothesis on the settlement of Easter Island (see below). A review of these observations is necessary in order to evaluate Langdon's ideas. My review here of protohistoric and early historic observations is not comprehensive (there were over 100 ships which visited or sighted Easter Island between the years 1722 and 1900; see Ayres and Ayres 1995), but the range of observations presented are representative.
The Dutchman Jacob Roggeveen was the first European to arrive at Easter Island (A.D. 1722). In his journal Roggeveen noted: “These people are well-proportioned in limbs, having very sturdy and strong muscles, are generally large in stature, and their natural colour is not black, but pale yellow or sallow …” (quoted in Sharp 1970:97).
Senior Lieutenant Alberto Olaondo, who sailed with the Spanish expedition under Captain Felipe González in 1770, noted that the Rapanui were “…mostly of good build, very robust, well made, extremely lively and lithe… All were of a brown colour, none black” (quoted in Langdon 1995a: 115).
In 1774 George Forster, the naturalist who sailed with Captain James Cook, observed:
From a few words which they pronounced, we concluded their language to be a dialect of Taheitian [sic]… Their whole appearance confirmed us in this opinion, and proved them issued from the same stock. They were of a middle stature, but rather thin; their features resembled those of the Taheitians, but were less agreeable (Forster 1777:557-58).
Not only did Forster note that the Rapanui “were inferior in stature to the natives of the Society and Friendly Isles [i.e., Tonga], and to those of New Zeeland [sic]” (1777:564), he also mentioned that
…the greatest singularity which we observed about them was the size of their ears, of which the lap or extremity was stretched out so as almost to rest on the shoulder, and pierced by a very large hole, through which four or five fingers might be thrust with ease (Forster 1777:558).
On the same voyage Cook noted:
In colour, features, and language, they bear much affinity to the people of the more western isles, that no one will doubt that they have the same origin….In general the people of this isle are a slender race. I did not see a man that would measure six feet (Cook 1777:290).
R. Guthrie, the ship surgeon of the H.M.S. Seringapatam, recorded in 1830 that- 163
…the men are Copper colored, Athletic, tall and well made. I saw none under five feet eight, and I measured one who was six feet three. 5 feet 10 inches is the medium size. In this respect we found them to differ much from Cook's description. The women and a few [of] the men are of a much lighter color. Their bodies are longer and the Pelvis narrower than those of England, or indeed in Civilized Europe; but their limbs, feet, hands, Eyes and teeth are handsome and beautiful. The men have all good teeth also, but I observed many to have one of the upper front teeth deficient…. The Women have all the lobe of the Ear cut, the circumference of the hole being from an inch to an inch + half (quoted in Fischer 1994:63-64).
The protohistoric period ended with the establishment of the first Christian mission on the island by the Frenchman Eugène Eyraud. In 1864 Eyraud observed:
The natives are tall, strong and well built. Their facial features more closely resemble those of Europeans than of other Pacific islanders. The Marquesans are, of all the Polynesians, the closest in resemblance. Their colour, being slightly bronzed, is not too different than that of Europeans, with a number of them being completely white (Eyraud 1866:55-56, my translation).
Pierre Loti, from the French naval ship La Flore, spent several days on the island in 1872. He observed, as had his predecessors, that the islanders shared an affinity with other Polynesians: “As for the inhabitants of Easter Island, they came from the west, from the archipelagoes of Polynesia; that is no longer questioned” (Loti 1991:14, my translation). He also commented further on the Rapanui appearance:
But, who are these Polynesians? That they are Maori [i.e., from Polynesia] is incontestable. Having become a little paler than their ancestors, due to the cloudy climate, they have kept their stature, attractive faces, which are generally oval-shaped and long, with their eyes approaching one another (Loti 1991:15, my translation).
An in-depth account was provided by Captain Wilhelm Geiseler of the Hyäne in 1882. Among other observations he noted:
The people who still inhabit Rapanui belong to the Polynesian race. In addition to the Polynesian tongue, their facial types and their habits and traditions also designate them to be Polynesians…. The men resemble almost entirely the Caucasian race in appearance and especially so in the shape of their heads. In general, their bodies can be described as slim and well formed although the muscle development in the legs appears to be noticeably less pronounced. The average height of a man seems to be 1.60-70 m, though one of the men was found to be 1.82 m tall. In comparison the women are smaller just as on other South Sea islands and in this respect they remind one of Japanese women.- 164
In general, their skin color looks very much like that of the Marquesans, but this is only superficially so; Easter Islanders have great nuance variations depending on age and exposure to the sun (quoted in Ayres and Ayres 1995:50).
He further added that “hair color is predominantly raven black…” (in Ayres and Ayres 1995:51), and that among the Rapanui the “teeth are straight; the teeth of younger people are dazzlingly white and hard, those of older people, for example, of 50 year old ones, are bad…” (in Ayres and Ayres 1995:52). Finally, he noted that “according to external appearances, not taking into consideration the coloring and the somewhat thin lower extremities, the men resemble Caucasians the most from among all the Polynesians” (in Ayres and Ayres 1995:52).
The first prolonged scientific research conducted on the island was by Katherine Scoresby Routledge during the period 1914-15. During her stay on the island, she meticulously recorded ethnographic and archaeological data. Among other things, she observed the ear length, skin colour, tribal boundaries and animosities on the island.
Roggeveen's description of the people as being of all shades of colour is still accurate. They themselves are very conscious of the variations, and when we were collecting genealogies, they were quite ready to give the colour of even remote relations… (Routledge 1919:221).
While she argued for the possibility of multiple racial origins, based primarily on skin colour, she did, however, note that
…the suggestion that Easter Island has been populated from South America may therefore, for practical purposes, be ruled out of the question. If there is any connection between the two, it is more likely that the influence spread from the islands to the continent (Routledge 1919:291).
However, Routledge also found evidence for a social division on Easter Island which she thought suggestive of multiple origins:
These ten clans were again grouped, more especially in legend or speaking of the remote past, into two major divisions known as Kotuu (or Otuu), and Hotu Iti, which correspond roughly with the western and eastern parts of the island…. If there have been two peoples on Easter Island, these divisions are one place where we must at least look for traces for it (Routledge 1919: 221-23).
To summarise these historical observations, the Rapanui were observed to be a group of Polynesians who were well-proportioned, muscular yet fairly thin compared with other Polynesians (possibly owing to food shortages), and of average height (men about 5' 9” or 174 cm). They were of variable skin colour although apparently becoming paler and more European in facial features with subsequent European visits, possibly suggesting gene flow. They also intentionally lengthened their - 165 earlobes and were socially divided into two main groups.
One factor that must be remembered in reviewing the historical accounts is the prevailing world view maintained by Europeans at the time. Europeans considered themselves to be the most civilised people on earth. Polynesians, because of their complex political organisations, technological achievements (as on Easter Island) and their ability to colonise the entire Pacific Ocean, were seen as being “somewhat civilised”. Thus the Europeans' bias may have influenced their view of the physical characteristics of Polynesians, regarding them as European-like.
These historical observations may provide clues in examining the question of Rapanui origins. Langdon (1994a, b; 1995a-d) has argued that Easter Island was first settled by South American Indians who were followed some time around 1680 by people of mixed Polynesian and European descent. The principal evidence for his argument rests on
(1) numerous descriptions of light-featured, European-looking Easter Islanders from Roggeveen's time onwards, and (2) the discovery in 1971 that 18 Easter Islanders with no known non-Easter Island ancestors were/ are carriers of certain genes that are peculiar to Europeans and especially common among Basques (Langdon 1995a:9).
In addition to the comments from Hagelberg (1995), and Bahn and Flenley (1995) regarding his hypothesis, I add additional comments. First, from the ethnographic accounts mentioned above, I would suggest that one reason for the European appearance of the islanders was possible gene flow with the earliest European visitors (primarily pre-1805). Also, comments regarding skin colour are somewhat subjective, especially when one considers that the sailors on the European ships would, most likely, have been deeply tanned after months of exposure to the sun. Second, as Hagelberg (1995) hinted but did not explicitly question, would the Polynesian/ European immigrants to Easter Island who theoretically wiped out the South Americans, in part by the various diseases they brought with them, be as susceptible as they apparently were to the European diseases brought by the European ships from 1722 onward?
Uncertainty concerning historic admixture with European and South American populations limits the use of genetic data in Easter Island research. This is especially evident when one considers that the Rapanui population dropped to a minimum of 111 in 1877 (Bahn and Flenley 1992). This severe bottleneck and the arrival of relatively large numbers of foreign immigrants has essentially ensured that the present Rapanui population is not genetically representative of the prehistoric Rapanui. Therefore, data derived from skeletal remains provide the most reliable source of genetic information on the prehistoric Rapanui.
Hagelberg (1995, Hagelberg et al. 1994) has examined mtDNA from osteological remains of 12 individuals from the sites of Ahu Tepeu on the west coast and Ahu Vinapu on the south coast of Easter Island (Fig. 1). Mitochondrial DNA is gaining - 166 status as a valuable research tool since it evolves more quickly than nuclear DNA, does not undergo recombination, and is only inherited from the maternal line (Hagelberg 1995). All 12 of the individuals examined demonstrate the 9 base pair deletion and substitutions at 3 particular locations (16217, 16247 and 16261), which indicate Polynesian ancestry. While her study is limited both in the number of individuals examined and the number and location of sites represented, it is in agreement with archaeological models which suggest a Polynesian origin for the Rapanui.
One other study based on genetic data is worthy of note here. Blood samples of Rapanui with no known foreign admixture were examined with the results for the highly polymorphic HLA system indicating that 36 percent (18 of 49) of the sample exhibited HLA type A29/B44 (12), most common among the Basques of Spain and France (see Dausset 1982). While Langdon (1994a&b, 1995a-d) uses this as evidence for prehistoric European gene flow via a mixed European/Polynesian population, the results can best be explained as the result of protohistoric gene flow with a Basque (or other European) sailor (see Bahn and Flenley 1992, 1995, and Hagelberg 1995 for an extensive rebuttal to Langdon, and Langdon 1995d for a reply).- 167
As in other bioanthropological areas of Easter Island research, osteological studies are not well represented in the literature. In addition to the studies by Murrill (1965, 1968) on the excavated material from the Norwegian Archaeological Expedition of 1955-56, the primary osteological studies are those of George W. Gill and associates at the University of Wyoming, where an extensive database representing over 400 Rapanui individuals has been assembled. However, most of the reports are preliminary in nature and many remain unpublished (Baker and Gill 1993, Chapman and Gill 1993, Gill and Baker 1986, Gill et al. 1983, Gill et al. 1993, Orefici and Drusini 1993, Tigner and Gill 1986, Zimpel and Gill 1986). Published reports include studies on the high frequency of caries (Owsley et al. 1983, 1985), the relatively low frequency of rocker mandible among prehistoric Rapanui (Gill 1990), an examination of pathology and intra-island variation for a variety of nonmetric and pathological traits (Gill and Owsley 1993), and an examination of the influence of European contact from osteological material (see Gill and Owsley 1993). In addition, there is an unpublished M.A. thesis (Chapman 1993) examining cranial nonmetric traits.
Preliminary results based on osteological data suggest the possibility of a small contribution to the Rapanui gene pool from a South American source (Chapman 1993, Gill et al. 1993). The possible South American contribution is believed to be minor and does not represent an American Indian colonisation of the island as Heyerdahl and Langdon would argue. Chapman (1993) demonstrates that a number of the nonmetric attribute frequencies differ significantly between various regional groups on Easter Island. When significant differences are evident, the attribute frequencies in the east tend toward frequencies found in Peru, whereas those in the west, particularly around Anakena, tend toward levels found elsewhere in Polynesia. It is important to note, however, that this analysis was limited in scope and awaits further confirmation using additional comparative samples from other Polynesian and South American locations. Gill and Owsley (1993) have also demonstrated a social division on the island which may have served to restrict gene flow between groups on the east and west sides of the island. This may help explain why no South American mtDNA was found by Hagelberg (1995, Hagelberg et al. 1994) because the sample she used came solely from the western part of the island. Mitochondrial DNA analysis of skeletal remains from the eastern part of Easter Island would be useful in further examining this question.
A major concern in the analysis of Rapanui osteological material is the possibility of protohistoric gene flow from outside sources. Gill (1986) has shown that the Easter Island skeletal material, examined in the osteological studies discussed above, is late prehistoric (1680-1722) and protohistoric (1722-1868). In a very thorough study, Gill and Owsley (1993) demonstrate that the Easter Island sample has received virtually no genetic input from Europeans (there was one individual who is believed to be of European/Polynesian descent). Likewise, protohistoric South American genetic influence would not be expected for several reasons. First, the majority of vessels visiting the island were European, with primarily European crews. Second, after the visit of the American ship Nancy in 1805, the Rapanui no longer received - 168 foreign vessels with the legendary Polynesian hospitality. Instead, foreigners were greeted with hostility and viewed with suspicion and distrust because the crew of the Nancy had kidnapped a number of Rapanui. Thus, gene flow from foreigners, including any South Americans who may have visited, essentially stopped. By this date, no more than a dozen foreign ships are recorded as having stopped at Easter Island. Third, no single individual displays American Indian traits to a significant degree. That is, no individual skull examined would be characterised in a forensic context as having enough significant genetic traits to be considered as mestizo or South American. Therefore, it appears that the possible South American genetic contribution is from the prehistoric period.
It is widely accepted that the first immigrants to Easter Island came from Polynesia. Possible contact with South America is generally viewed as the result of Polynesian voyages (Irwin 1990,1992; Orliac and Orliac 1988) rather than Peruvian expeditions into the Pacific (as suggested by Finney 1993). Preliminary results based on osteological studies suggest that South American Indians possibly made a small contribution to the Rapanui gene pool (Chapman 1993, Gill 1994).
Three settlement hypotheses have been suggested which could account for the hypothesised South American genetic influence upon the Easter Island population. The three are briefly presented here. The first hypothesis, advanced by Heyerdahl (1961, 1989, 1993) and presented by Langdon (1994a&b, 1995a-d) with a similar model, envisions an initial colonisation of Easter Island by South American Indians and a later wave of settlement by Polynesians. Heyerdahl bases this argument partly on island folklore as well as on early historical accounts. The first group to arrive on the island (South Americans) were known as the Hanau eepe ‘Long ears’, while the second group (Polynesians) were known as the Hanau momoko ‘Short ears’. The South Americans were responsible for the megalithic statues, rongorongo writing, the facing on the ahu (ceremonial platform) at Vinapu, the tupa (a stone structure found on the island similar to Peruvian chullpa) and the bird-man motif, among other things. He also suggests, based on Rapanui legends, that a civil war erupted between the ‘Long ears’ and the ‘Short ears’ in which all the ‘Long ears’ men were killed, with some of the women and children absorbed into the ‘Short ears’ population, thus explaining why the population was Polynesian at the time of European contact.
The second hypothesis was first proposed by Englert (1970) and Bellwood (1978), and has been resurrected in Chapman (1993). It is loosely based on the Rapanui legend of the Hanau eepe and Hanau momoko recorded by Englert (1970). Briefly, the legend mentions the arrival of a second group of individuals to the island after the initial settlement who remained, more or less, a distinct group. If the second group or immigrants came from South America, this legend could help explain why a small amount of apparently South American genetic influence is present on Easter Island and why the genetic and possible cultural influence is restricted to certain regions, such as the east. Bellwood (1978) suggests that this contact may have occurred during the Middle Period (A.D. 1100-1680) of Easter Island's prehistory - 169 (see also Skjølsvold 1994).
The third, and most recent, hypothesis by Gill et al. (1993, Gill 1994) suggests that
…an East Polynesian migration, probably from the Marquesas Islands…made landfall in the Americas. Over a period of years the Polynesians came to inhabit and explore the coastal islands and the coast itself of South America, borrowing some cultural elements, losing others and developing some unique ones. In an attempt to return to East Polynesia on a new colonizing voyage, they were swept into the Humboldt current and eventually arrived on Easter Island (Gill 1994:17, original emphasis).
The mtDNA results mentioned above, in addition to archaeological findings (see Golson 1965, and Bahn and Flenley 1992, among others), would appear to make Heyerdahl's hypothesis untenable and also Langdon's by association. Heyerdahl (1993) counters that this in no way affects his hypothesis since the American Indians would have cremated their remains thus leaving behind no trace of their presence on the island. However, a recent study by Skjølsvold (1994) has identified bones of the Polynesian rat (identified as Rattus concolor, although the appropriate designation is Rattus exulans, according to Elizabeth Matisoo-Smith, pers. comm.) from the earliest cultural layers. This finding provides further evidence that the Polynesians were the original settlers of Easter Island and not South American Indians.
Gill's hypothesis, while adequate for explaining the similarities of certain Rapanui biological attributes to South American Indians, including lower frequencies of rocker jaw on the island in comparison to the rest of Polynesia (Gill 1988, 1994), does not explain why some traits are found primarily in the eastern part of the island and not in the west (see also Bahn 1994 and Gill 1994 for additional comments and explanations). This hypothesis is, therefore, insufficient to explain the osteological findings.
The second hypothesis above best explains the regional variation of cranial nonmetric traits as well as possible gene flow with South American Indians. While the mtDNA results mentioned above demonstrate no South American influence, the results do not necessarily invalidate the second hypothesis, since the samples used in the study were entirely from the western part of the island, while the similarities to South American Indians are found primarily in the eastern part of the island (Chapman 1993).
Additional evidence suggesting the segregation of the Rapanui into two groups may be found in a rock art study. Lee (1992:45) noted that
…a study of the distribution patterns of certain motifs reveals that many motifs cluster along the coastline in specific parts of the island and often in association with important ceremonial places. These clusterings may be identified with kin groups, economic activities, or ritual and ceremonial places, or they may be indicators of status.- 170
There appears to be a significant boundary, based on motif locations, between the eastern and western parts of the island:
It is said on the island that the Makemake face (in the form of an eye mask) was a special motif relating to the Mini tribe. There is a cluster of these faces on the north coast near Anakena; however, they also appear in many other parts of the island. They are conspicuously absent from that portion of the north coast from the tip of Poike to Ava O Kiri [i.e., the north-east coast] (Lee 1992:60).
Lee (1992:64) also notes that “aside from absolute numbers, The distribution of [the komari (vulva petroglyph carving)] is unusual. It is completely absent on the north coast from Poike all the way to Ava O Kiri”.
A possibly significant finding discussed in the same study suggests that a particular motif which at one time was found along the entire north coast was later restricted to the Miru area:
… the distribution of fishhook designs suggests that, in earlier times, one clan, probably the Miru, controlled the entire north coast, including the northern half of the Tupahotu and the Poike Peninsula. There is one difference, however; we do not find fishhook motifs carved on fallen moai [stone statues], pukao [stone topknots for moai], or on the facia of ahu [ceremonial platforms]. Whatever they may have signified, they probably were not clan symbols unless they date from a very early time period (Lee 1992:115).
This unusual occurrence would be explained if a second group of individuals immigrated to the island, as indicated in the legend referred to earlier, and lived in the northern half of the Tupahotu region, which was originally part of the Miru tribal area. Thus, Lee's observations appear to fit well with the second hypothesis.
The hypotheses presented by Gill et al. (1993) and Englert (1970) above are not mutually exclusive, although the likelihood of both events occurring is certainly debatable. Bahn (1994:40) criticises these two hypotheses noting that
…it is odd that [the South Americans] should not have conveyed the concept of pottery or pressure-flaking to the islanders; after all, some would have us believe that they brought ideas in art and architecture with them.
Thus, while capable of explaining a limited amount of South American Indian gene flow into the Rapanui population, the hypotheses are still lacking in that they fail to explain, according to Bahn (1994), the lack of important aspects of South American material culture on Easter Island.- 171
There is a wide range of speculation on alternative biological origins of the Rapanui people with recent publications giving new life to old hypotheses and debates. The three main hypotheses which allow for a South American presence on Easter Island in prehistory include: whether South American Indians were the first to settle the island followed by immigrants from Polynesia (Heyerdahl 1961, 1989, 1993; Langdon 1993, 1994a&b, 1995a-d); whether Polynesians were the first to settle the island with later gene flow from South American Indians (Bellwood 1978, Chapman 1993, Englert 1970, Skjølsvold 1994); or whether a mixed Polynesian/South American Indian group first settled the island (Gill 1994, Gill et al. 1993).
Of the hypotheses presented above, the one advocating a secondary immigration to Easter Island from South America first presented by Englert (1970) and later by Bellwood (1978) and Chapman (1993) best explains the apparent presence of South American genes on the island accounting for their regional patterning and is in accordance with recent archaeological findings (Skjølsvold 1994). This hypothesis is based on a Rapanui legend which tells of a second “settlement” of the island with the new immigrants remaining, more or less, a distinct group. Preliminary osteological studies (Chapman 1993, Gill 1988, Gill and Owsley 1993) lend support to this hypothesis while mtDNA studies (Hagelberg 1995, Hagelberg et al. 1994) do not eliminate the possibility. In addition, rock art studies (Lee 1992) also lend support to the idea of two distinct groups on the island at the same time in prehistory.
This evaluation of the hypotheses for gene flow between the Rapanui and South American Indians is based primarily on preliminary biological data. A broader examination incorporating archaeological, cultural and linguistic data will be essential to acquire a better understanding of Easter Island prehistory. In addition, given the relative lack of biological studies of the Rapanui in comparison to archaeological studies, a renewed emphasis must be placed on this important area of Easter Island research.