D ATA U S ED ..... It is the author's opinion, shared by others (Laughlin .... Sincere thanks are also given to Professors Edward E. Hunt, Jr., W. W. Howells and Bin ...
Application of D istance Statistics to Anthro
poscopic D ata an a Com parison of R esult
with those obtained by using iscrete
Trai s of the Skull
By MICH EL PIET R USEWSKY
171-/
Repr inte d f rom A r chueoloqy 12' I'h ysical A nthropology A pr il, 1971
!II
O ceania, Volume V I , N o. r,
APPLICATION OF DISTANCE STAT ISTICS TO ANT HROPOSCOP IC DATA
AND A COMPARISON OF RESULTS WITH THOSE OBTAINED BY USING
DI SCRETE TRAITS OF THE SKU LL
By
MICHAEL
P IETRUSEWSKY*
I NTRODUCTION
THE Bayar d Domini ck E xp edition to Polyn esia began in the sum mer of 1920 the collection and subs equent publication of numerous somat ological observations on the inhabitants of various P olynesian islands (Sullivan, 1921, 1922, 1923, 1927 ; Shapiro, 1930 ; MacGregor, 1932). Th ese stud ies included the then customary an thropometric and anthroposcopic descriptions, st andardized by Louis R. Sullivan to ensure uniformity of t echnique among t he several field work ers involved . Th is precaution was taken so that subsequent comparisons of results would be possible. In this paper multivariate analyses of distance ar e applied to percentage inciden ces of certain anthroposcopic traits representing severa l islan d groups wit hin Pol ynesi a . These findings ar e then compared with measures of divergence based on the percentage incidences of discrete traits of the skull previously calculat ed (Pietrusewsky, 1969, 1970). The distance statistic used in both cases is Berry and Smith's Distance Stat istic (Berry and Berry, 1967) which has , in t he author's experience, satisfactorily demonstrated inter-group relationships. Despite th e application of sophisticated statist ics, it might be argued that incidences of anthroposcopic traits such as hair colour, amount of beard, lip thickness, body hair and slope of foreh ead may not reflect biological divergences because of their rather vague genetic bases (a claim whic h may also be made, but not as strongly, for the discret e traits of the skull). It should be pointed out, however, that not all th e characte rs to be used are of an equally dubious nature. Some, such as eye colour, epicanthic eye fold, attached ear lobes and shovel-shaped incisors, add a little more credibility to what is being attempted here. Howells (1966) has shown t hat useful measures of distance can be obtained on appli cation of multivariate analyses to similar kinds of data, or what he calls SCOPIC traits. Regardless of the difficulties, th ese data, both stomatological and skelet al, do remain th e best characterizations of Polynesian populati ons at our disposal. Modern genetic studies on pr esent-day inh abitants of these islands hav e fairly limited value in predict ing form er identities and relationships, becaus e of t he interbreeding and merging which ha s taken place since conta ct times. This has been so extensive that for all intents and purposes the original or Polynesian genetic composition of these island inh abitants has been lost . Both Pollitiz er (1958. p. 256)
* Department
of Ant hropology, Universit y o f H aw aii , Honolulu.
22
AP PLICATION OF DISTANCE STATISTI CS
and Hanna (1962, p. 499) point out some of the disadvantages of blood group gene frequencies in their studies, such as their marked t endencies t o be affected by random tluctuations, sampling error and migr at ion, giving rise t o false impressions of historical relationships. Th e same two authors also feel that dist ance analyses of morphological traits should, on the other hand, yield more accura t e patterns of relationships. r Papers by Sangh vi (1953) and H iern aux (1956) also tend t o reinforce this opinion. An excellent essay reviewing the limitations of allelic frequencies for reconstructing earl y popul ations is Hunt (1959)' Further, ·Simmo ns (1965) is similarly convinced that blood group gene frequencies are of limit ed va lue in reconstructing biological relat ionships of past populat ions of Oceania . H owever, nothing can be lost from an attempt to rework some of th e existing data. D ATA U S ED
A nthroposcopic Characters Twenty non-metri cal characters used in each of the somatological st udi es were select ed to allow as many comparisons as possible between t he samples. A single variation of each character was selected t o represent a st andar d for t hat charact eristic. The 20 characters used and the select ed va riat ion of each are list ed in Table 1. A more complete listing of t hese characters, along with their numerous expressions and the techniques used in scoring them ma y be found in the first cont ribution to t he series of publications on Polynesian soma tology (Sullivan , 192I ). T AB L E
1
A nthroposcopic Characters Used 1. 2.
3. 4. 5. 6. 7. 8. g. 10. II. 12 .
13 . 14. 15. 16. 17. 18. 19. 20.
Hair form (st rai gh t ) Hair colour (dark a nd r edd ish brown ) Amount o f b eard on ch in (h eavy) Am ou nt of h air on chest (h eavy) Amo u nt of h air on forea rm (hea v y) Amount of h ai r on legs (h ea vy) E y e colour (bla ck ) Conju nctiva (clea r) Epica nt h ic ey e fold (m ark ed) Na sa l brid ge (high) Axes of n ostri ls (ob liq ne) Slope of foreh ea d (ver ti ca l) Glab ella (smoot h) Lip thickness (th in) P rogn a th ism (presence) Ear lob e (attach ed) H elix ro ll (rolled t hroughou t ) D ar win 's tub er cle (presen ce) Shovel-shaped lat eral in cisors (m arked ) Sh ove l-shap ed cent ral in cisor s (marked)
clmples The samp les provid ed dat a on male inhabit ants from t he island s of Tonga, Samoa , ociety, Marquesas, Tokelau , Hawaii and also on mixed H awaiians. All the dat a
APPLICATION OF DISTANCE STAT:ISTICS
23
come from the published literature, except t he Tokelau material, which is from original records of Gordon MacGregor, kept at the B. P . Bishop Museum in Honolulu. The ources and maximum size of each sample (based on ind ividu als) ar e ou tlined here. Samp le Size
Island Gro up Samo a (Sava ii a nd Upolu ) T on ga-all m aj or islands Marquesas- all maj or islands Haw ai i-all m aj or islands Mixe d Hawai ian .. Societ y- all m ajor islands T ok elau (At a fu)
70
118 84 29 6 121
85 85
Source Sulliva n, 19 21 Sullivan, 19 22 Sulliva n, 192 3 Sullivan, 19 27 Sullivan, 1927 Shap iro, 1930 Ma cGregor , 19 32
Tonga, Samoa and th e Tok elaus are III western Polynesia, the Societ y, Marquesan and Hawaiian groups in east ern Polynesia. The mixed Hawaiian sample was included as a control in th ese analyses, in hopes of accent uati ng t he degrees of relat edness between the other samples. T ABLE
2
T hirty -eight Di screte T raits of the S kull to 'which
D istance Analyses were A pplied
I. 2.
3. 4. 5. 6. 7. 8. 9. 10 . II.
12. 13.
r 4. 15.
r 6. 17.
18. Ig . "20 .
'2 1. 22 .
23 .
24. 25. 26 . 27.
28. 2g . 30.
31. 32.
33. 34. 35. 36. 37. 38.
Metopic suture presen ce Fe male fro ntal grooves (RL) S upra-orbital foramen multiple (RL) Righ t parietal foramen absen t Coronal wormians Sagi ttal wormians Lam bdoi d a l wormians Epip t eri c bones (R L) Tympan ic thickening (R L) T y mp anic d eh iscence (R L) F emale audi tory exo st oses (RL) Aste rio n ic tuber cles (R L) Fe male p ariet al notch bone (R L) F emale occ ip ut form mou nd Os inca Occipital condyles double (R L) Anteri or con dylar ca na l m ul ti p le (RL) Posterior condyla r ca nal abse n t (RL)
P recondyla r tuber cle
Paramast oid p roc ess (R L)
Ossifi ed apic al ligament
Ovale-sp inosum com mo n (R L) Sag ittal sinus t o left Nasal-fro nt al su t u re round I nfraorbi tal foramen double (RL) Os [apo nicum Sub nasal region blurred Zygomaxillary t ubercle (RL) Marginal tuber cle (RL ) F emale m ala r t uber osity (RL) Palatine t orus Palatine su t u re anteriorl y rounded Ch in form ang ula r Ma ndi b ula r t orus Myloh yoid a rch (RL) Mandib ul ar foramen m ultiple (RL) Mental fora me n multiple (R L) R ock er jaw (R L) = per sid e incidenc e of trait t aken.
APPLICATION OF D ISTANCE STATISTICS Discrete Tr aits of the S kull Th e islands from which percentage incidences of the discrete trait s of the skull were drawn include Ton ga-Samoa (combin ed sample here), Fiji, Hawaii , Marquesas, Easter Island, New Zealand, Chat ham Island, Society and Tuamot u. The number of observations recorded va ries considerably within each sam ple, because of the combinat ion in some cases of sex and side incidences, as well as t he variable st ate of preservation of the skulls (see Table 2). The 38 characters, which have been described elsewhere (Piet rusewsky, 1969), are merely list ed here (Table 4) Hen)' and S mith 's D istances B ased
Tonga ·. Sa m oa .. Societ y ·. Marquesas Hawa ii Mix-Hawaii Tok ela u · .
T ABLE 3 T wenty Anthrop oscop ic Characters f or Seven P oly nesian Samp les
Tonga
Sa m oa
Soc iety
Ma rquesas
H a wa ii
MixH aw a ii
Tokela u
(118)
(7°)
(85)
(84)
(296)
(121)
(85)
0 -° 483
0 -6968 0- 6424
0 -3442 °'3 286 0 ' 1657
0 ' 1657 0 ' 1457 0 ' 9° 56 0' 6184
0- 3369 0 ' 6°3 8 0'5 6° 9
° ' 326 4 0'2593 0 ' 1457 0 -3369
° ' 3 23 2 0 ' 2587 0 ' 9° 56 °' 6° 38 0' 2388
0 '9620 0' 9° 4 1 ° ' 618 4 ° ' 5609 ° ' 5627 1 ' 0028
-
-
° '°4 83 0' 6968 0 ' 344 2 . ° '3 264 0 -3232 ° ' 9620
.
all
0' 64 24 ° '3 286 0- 2593 0 ' 2587 0 '9° 4 1
-
-
-
-
0 -2388 0 ' 5627
1' 0028
-
Nu m be rs in pare ntheses indicate m ax im u m sa mp le size for each isla n d gro up.
T AB LE
4
Berry and S mith's Distan ces Based on T hir ty -eight Characters of the Skull f or Nin e P acifi c I sland Group s
TongaSa moa Fiji .H a waii Ma rq uesas Eas t er .. N ew Zea la nd Ch at h a m Is. Soc iet y T uamotu
T ongaSamoa
Fiji
H awaii
Ma rq u esa s
E a ste r
(4 1)
(44)
(131)
(115)
(72)
(49)
(42)
(55)
(32)
0 - II 34
0 - 1552 ° '°986
0 '1191 0 ' 1015 0 -03 13
0 ' 2506 0' 1511 0 '°4°9 ° '°388
0 ' 3260 0 - 2136 0 '°77 1 0 ' 1249 0 ' 08 71
0' 25° 1 °'°53 6 0 '° 624 0 ' ° 57°
0 ' 1553 0 ' 1614 0' 1124 0 '°4 21 ° ' ° 780
0 ' 1832 0 ' 284° 0 ' 1891 0 ' 16II 0 ' 1856
0'°578
0 ' 1266
0 ' 2393
° ' 0836
0' 265 3 0 ' 1292
-
-
0 ' II 34 0 ' 1552 0' II91 0'25°6
0 ' ° 986 0 - 1015 0' 1511
° '3 260 0' 25°1 0 ' 1553 0 -1832
-
-
0 -°3 13 0 -0409
0'°388
°' 2136
0'°77 1
0 ' 1249
0 ' 087 1
0'1 216 0' 1614 ° ' 28 4°
° '°53 6 0 ' 1124 0 ' 1891
0 ' 0624 0 '°4 21 0 '1 611
0 -0570 0 ' °7 80 0 ' 1856
-
New Chat ham Zea la nd I s. Soc iety Tu a mot u
-
0 ' °5 78 0'1 266 0 '23 93
0 '
I'l16
-
0 ' 0836 0 - 2653
-
0 ' 1292
-
Nu mb ers in p arent heses in d icat e num b er of sku lls u sed . R E SULTS OF B OTH T RI ALS
Distances Based on the A nthroposcopic Data The distan ces obtai ned by the applicat ion of distance analyses to th e percentage incidences of the 20 charact ers are set out in matrix form (Table 3), These result s
APPLICATION OF DISTANCE STATISTICS
have been illustrated by means of the so-called shaded-similarity ma trix technique (Figur e 1) suggest ed by Sokal and Sneat h (1963, p. 176), which clarifies inter-grou p 'relationships not apparent on mere inspection of the dist ances. Three fairly distinct clusters result, the first formed by a strong association bet ween Tonga and Samoa . A second larger clust er comprises H awaii, Society and th e Marquesas, t he last sample displaying only moderate affinities to the Hawaiian sample, T he mixed H awaiian sample occupies an intermediate position between t he first two clusters, being only loosely associated with the Hawaiian and Samoan samples of t hese.
T
S
0 N G A
A M
H A
M H I A XW E A D I I
W A I I
0 A
S
T
M A
o
0
a
C
K
I
E
R
U E
E
L
A
T
A
Y
U
S S
T O N GA
S A MO A
HAW AII MI X ED HAW AII
SOCI ETY
T OKEL AU
o
····· ..... ·· ..
,15
,3 0
.4 5
.60
.75
.90
1. 0 0
D I STA N CE VA L UE S
Figure I. - A shaded similarity matrix based 0 11 B erry a nd Sm it h 's Dist a nces for 2 0 a nthroposcop ic ch aracter s.
26
AP PLICATION OF DI STANCE STATI ST ICS
The third and final cluster is repre ented by t he Tok elau sample alone. With two except ions, the degrees of divergence in this comparison are of a much greater magn itude than even t he dist ance obtained in comparisons involving the mixed Hawaiian sample. Oddly enough, the Tokelau's closest affinit y seems to be with T ONG A
SA MO A
MI X E D HA WAII
HA WA II
SOC I E T Y
M AR QUES A S
TOKELAU
00
.0'
" IJl W
o
I
.2'
_ _ _ _ _ _ _ _
Z
_
I I I J
...'" . 3 ' IJl
a IJl
:::
.4'
...
:l; IJl
.ee
a
z .0'
'"
> a: . 15 a: w
III
.0'
.9 '
'0' Figure 2.-A hierarchal schemat ization o f d iv ergen ce b ase d on Berry and
Smith 's Distances for 2 0 a nt hrop oscop ic charact ers.
eastern rather than western Polynesia. In another schematic representation Sokal and Sneath 's elementary cluster analysis (Sokal and Snea th, 1963, p. 179), these associations are more obvious, and some indication of relationships between clusters is apparent (Figure 2). Distances Based on Discrete Traits of the Skull
Measure s of div ergence obtained earlier using 38 non-metrical characters of the skull (Pietrusewsky, 1969, 1970) are presented here for comparison (Table 4). Th e ame methods of illustrating these results are employed (Figures 3 and 4). The se results indicate a strong association between Tonga-Samoa and Fiji in westem Polynesia-eastern Melanesia. Other clusters formed include the association of ociety and Tuamotu in central Polynesia and the very close bond between the Marquesas and Hawaii. Easter Island, Chatham Island and New Zealand samples, r presenting islands of marginal eastern Polyn esia, form a final cluste r.
27
APPLICATION OF DI STANCE STATISTICS T S OA
F I
NM
J
GO A A
I
T U A M
0 C I
H A W A
0
E T
I I
S
T U
M
A R
0
U E S A S
Y
E A
S T E R
N Z E E
C H
WA
A
L A N D
T H A M
TONGA SAMOA FIJI
TUAMOTU SOCIETY HAWAII MAROUESAS EASTER NEW ZEALAND CHATHAM
o
.O D
.10
.15
.2 0
.2 D
.3 0
==T7""
