close

Вход

Забыли?

вход по аккаунту

?

Ecological factors in skin color variation among Papua New Guineans.

код для вставкиСкачать
AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 66:407-416 (1985)
Ecological Factors in Skin Color Variation Among Papua New
Guineans
ROBIN G. HARVEY
SubDepartment of Anthropology, British Museum (Natural History),
London SW7 5BD, England
KEY WORDS Papua New Guinea, Skin color, Reflectance
spectrophotometry
ABSTRACT
An EEL reflectance spectrophotometer was used to measure
the skin color of the inner upper arm and the forearm of 913 Karkar Islanders
(Madang District) and 684 Lufa villagers (Eastern Highlands District). The
samples were subdivided to study sex, age, and population variation against a
background of ecological observations, including sunlight exposure, clothing,
and erythemally effective wavelengths of ultraviolet light (Robertson, unpublished Ph.D. thesis, 1974). Population differences in sex and age variation in
upper arm skin color may largely be attributable to the effects of culturally
associated clothing differences. Not only do the Lufa villagers wear substantially less clothing than the Karkars, but also their arms are exposed more
frequently to ultraviolet light during heavy manual work in unshaded gardens. For the melanin content of the forearm skin there are similar patterns
of age variation in both populations; however, the populations differ in mean
percentage of reflectance throughout most of the age span. These betweenpopulation differences are interpreted as a consequence of greater average
daily exposure to sunlight and the higher intensity of ultraviolet light in the
highland environment. On the forearm the percentage of reflectance at 685
nm decreases more rapidly with age in the prepubertal and adult age groups,
a result attributed to endocrine changes superimposed on cumulative changes
in the melanin pigmentary mechanism.
Studies of the variation in skin color with
age by reflectance spectrophotometry have
shown that age trends are variable between
different human populations (Conway and
Baker, 1972; Kahlon, 1976; Byard and Lees,
1982). There appears to be a general tendency for melanin pigmentation to increase
from early childhood to adolescence, and this
may become more pronounced around puberty. After puberty the pattern of variation
seems to depend on whether melanization is
being measured on skin surfaces frequently
exposed to sunlight or on surfaces generally
shielded from solar ultraviolet radiation.
Even brief exposure to ultraviolet light W L )
may result in persistent changes in the cutaneous pigmentary system; therefore, it is
virtually impossible to isolate through reflectance measurements alone the characteristics of what Quevedo et al. (1975)have termed
0 1985 ALAN R.LISS, INC.
“constitutive” skin color (the genetically determined melanin pigmentation of the skin
generated in the absence of light radiation
influences) from those of “facultative” or inducible skin color. Some progress can be expected, however, if opportunities are taken
to examine quantitative characteristics of cutaneous pigmentation against a background
of ecological factors in human population
studies. The International Biological Programmemuman Adaptability Project (IBP/
HA) fieldwork on coastal and highland Papua
New Guineans, conducted between 1968 and
1972, provided one such opportunity.
This report concerns the spectrophotometric characteristics of skin color in two Papua
New Guinea populations living under conReceived April 20, 1984; revised October 9, 1984; accepted
October 18.1984.
408
R.G. HARVEY
trasting environmental conditions-one in
the coastal lowland region of the Madang
District on the volcanic island of Karkar, the
other in the Eastern Highlands District, a t
Lufa on the slopes of Mt. Michael. Age
changes in melanization of inner upper arm
and forearm skin surfaces are examined cross
sectionally against the background of genetic, ecological, and sociocultural differences between these two Melanesian
populations.
MATERIALS AND METHODS
The Karkar Island sample consisted of 407
males and 506 females from seven villages
in the northern, Waskia-speaking part of the
island (N = 821) and two villages in the
southern, Takia-speaking part (N = 92). All
the villages were situated at a n altitude less
than 150 m. Serological and biochemical genetic differences between these two language
groups have been reported (Boyce et al., 1978;
Serjeantson et al., 1983). Initially, therefore,
their skin reflectance measurements were
analyzed separately. As no significant differences were found, Waskia and Takia results
were amalgamated.
The Lufa sample consisted of 310 males
and 374 females from seven Yagaria-speaking villages of Lufa subdistrict, situated at
a n altitude of approximately 1,900 m. The
age structure of the Karkar and Lufa samples is given in Table 1.
Considerable ecological differences exist
between the two populations (Budd et al.,
1974; Norgan et al., 1974; Hornabrook, 1977).
The Karkar Islanders live in a hot, humid
environment and cultivate gardens of food
crops for subsistence and coconut plantations
with cocoa for cash. Europeans introduced
new religious practices and Western-style
clothing a t the end of the nineteenth century,
in contrast to the Lufa highlanders, where
first contacts were made during the 1930s
and had little cultural impact. At the time of
the IBP/HA study the highlanders were
mainly engaged in subsistence horticulture,
which involved strenuous physical activity
in steep terrain. Their life-styles had been
influenced considerably less by external factors than those of the coastal villagers of
Karkar Island.
Measurements of cutaneous pigmentation
were made with a n EEL reflectance spectrophotometer a t two sites, the inner upper arm
and the forearm. All measurements were
taken by the author, and the same galvanometer unit, applicator head, and light bulb
were used a t both localities. The skin was
cleansed before measurement and three filters of the EEL instrument were used (601,
605, and 609), giving percentage of reflectance readings at 425 nm, 545 nm, and 685
nm.
Observations of the amount of time spent
in sunlight (whether or not it was strong
enough to cast shadows) during daily activities were obtained for 26 males and 30 females of Karkar and 29 individuals of each
sex a t Lufa, using the technique of direct
observation and logging. Subjects were followed continuously during the hours of daylight and records were made every minute of
their status with regard to sunlight exposure. The individuals sampled were engaged
in a pattern of activities that was considered
representative of the village populations chosen for the investigation of skin color. The
observations were made by Dr. G. M. Budd
and Dr. Leigh Hendrie of Sydney University
TABLE 1. Age structure of the Karkar and Lufa samples
Age (years)
Under 5
5-10'
10-15
15-20
20-30
30-40
40-50
50-60
Over 60
Total
Males
(N)
26
75
59
29
69
73
37
25
14
407
'5.001-10.000,
and so forth.
Karkar
Females
(N)
21
71
81
69
102
72
47
33
10
506
Males
(N)
4
37
51
30
56
67
43
21
1
310
Lufa
Females
(N)
6
40
58
41
90
86
45
8
374
SKIN COLOR VARIATION AMONG PAPUA
during a study of thermal stress. Skin reflectance measurements, taken by the author a t
the same time a s this study, are available for
99 of the sunlight exposure (SE)subjects aged
between 14.8 and 32.0 years and are summarized with the total skin color samples
(>20 years) in Table 2.
RESULTS
Skin site and population differences
The majority of interpopulation comparisons by other authors have been made on
samples of adults. Initially, therefore, in Table 2 the results for the major samples are
presented for individuals over 20 years of
age. Mean percentage of reflectance from the
upper arm is greater than from the forearm.
The largest skin site differences occur a t the
longest wavelength (685 nm), where they
range from 8.8 to 11.8% in the large population samples and between 7.4 to 11.5% in the
sunlight exposure (SE) samples. The highest
coefficients of variation are found in the upper arm measurements at 545 nm (14.818.1%).
In the large population samples the reflectance values are higher in females than in
males at both skin sites and a t all wavelengths. Differences are significant in both
populations in forearm reflectance (P < 0.05)
and fail in only two instances to reach the
5%level of significance in upper arm reflectance (Lufa 425 nm and 685 nm). Sex differences are greatest in the upper arm
measurements of the Karkar Islanders.
In the sunlight exposure samples the results follow a very similar pattern. The majority of the reflectance values are higher in
the females than in the males, significantly
so in the forearm measurements. Skin site
differences within populations are significant at all wavelengths.
With one exception (males, upper arm, 685
nm), Lufa skins reflect less light than those
of the Karkar Islanders. The lighter skin
color of the Karkars is most clearly evident
on the forearm, where all the interpopulation
differences are highly significant (P <
0.0001).
The frequency distributions of reflectance
measurements show significant positive
skewness, with the exception of the upper
arm measurements a t 685 nm. Log transformations of reflectance measurements were
made in a n attempt to normalize the distributions. An antilog transformation of reflectance measurements was also attempted,
409
following the recommendations of Harrison
and Owen (1964). The effects of the transformations on each of the four principal subsamples was so inconsistent that they were
abandoned in favor of using the original raw
percentage values. The significance test used
(the standardized normal deviate) was appropriate for sample distributions with varying
degrees of skewness.
Age changes
The analysis of age-related changes in skin
color concerns measurements a t 685 nm. Reflected light at this wavelength is influenced
maximally by the concentration of melanin
in the skin and minimally by the amount of
blood flow (Harrison and Owen, 1956;
Harmse, 1964).
Figure 1 shows mean percentage of reflectance a t 685 nm plotted against age, subdivided by 5- and 10-year cohorts, for the upper
arm. Clearly the age trends in the two populations are substantially different. For the
Karkar Islanders the sex differences noted in
the adult samples are evident in the separate
age cohorts and are especially marked
around 5-10 years and 20-40 years. In both
sexes the mean values of percentage of reflectance reach their lowest levels around 10-15
years and increase sharply during early
adulthood, especially in females. From the
30-40-year cohort the means decrease and
continue to decline into late adulthood (6070 years in these populations).
Among the Lufans a n entirely different
pattern of age variation occurs. There are no
significant sex differences in any of the age
cohorts, and, in contrast to the Karkars, their
skin reflectance means show a decline from
early childhood to 20-30 years, followed by a
variable trend in the remaining adult period.
There are large standard errors of the mean
values in the 50-60-year age cohort, mainly
because of the smaller numbers in these
samples.
The forearm reflectance measurements
show a more consistent pattern of variation
in both populations (Fig. 2). Percentage of
reflectance values are correlated significantly with age, the highest correlation occurring in the Lufa males (r = -0.6471, the
lowest in the Karkar females (r = -0.395).
There is evidence in Figure 2 that the relationship with age may be composed of two
components, the first of which (a prepubertal
phase) shows a more rapid decline with age
than the second, postpubertal and adult
Karkar (M)
SE
Karkar (F)
SE
Lufa (M)
SE
Lufa (F)
SE
215
22
265
27
189
23
229
25
217
22
265
27
189
23
229
25
7.38'
8.35'
7.70**lt
8.11t
6.38
6.48
6.91**
7.02**
9.62+
10.81'
10.lO**,t
10.54'
9.14
9.33
9.31
9.58
Mean
1.14
1.44
0.88
1.00
0.67
0.77
0.74
0.91
1.43
1.53
1.44
1.37
1.25
1.43
1.52
1.11
SD
425 nm
1.08*
0.31
1.20%
0.92*
0.85*
0.42
0.57'
0.01
0.74*
0.77*
0.87*
0.40*
1.36*
0.62'
0.88'
0.86'
El
8.80-
9.23+
10.57'
9.90*'st
10.46'
7.84
8.00
8.65**
13.81t
14.96
15.02**,'
15.19'
13.29
13.49
13.79*'
14.24
Mean
0.05 for significance of g,.
P < 0.05 for significance of sex difference-within-place, within-skin site.
+P < 0.05 for significance of population difference-within-skin site, within-sex.
"P c
**
~
Forearm
. .
.
Uooer arm
Karkar (M)
SE
Karkar (F)
SE
Lufa (M)
SE
Lufa (F)
SE
n
1.42
1.45
1.23
1 30
0.87
0.96
0.97
1.12
2.34
2.42
2.68
2.26
2.25
2.44
2.47
2.27
SD
545 nm
0.940.64
0.46%
0.17
1.01'
-0.16
1.00*
0.98*
0.72*
0.840.59*
0.32
0.62'
-0.25
0.85 '
0.38
el
22.02'
25.04'
23.96";.'
25.89+
19.01
19.61
21.06'*
21.77
30.78
32.43
33.24",'
34.07
30.83
31.10
31.58
31.93
Mean
3.21
3.29
3.20
3.65
2.56
2.88
2.83
2.97
4.41
3.98
4.42
3.87
4.51
4.51
4.44
3.92
685 nm
SD
0.83'
1.01'
0.44'
1.38:
0.87
0.08
0.71'
0.89*
0.12
0.52
0.00
-0.01
0.13
-0.10
0.32
0.19
El
38.7
23.3
37.1
20.2
38.9
25.8
36.1
23.8
38.7
23.3
37.1
20.2
38.9
25.8
36.1
23.8
Age
(mean)
TABLE 2 Mean, standard deviation (SO), and skewness (g,) for the drstribution ofpercentage ofreflectance at three wavelengths in individuals over 20 years
of age (major samples) and in sunlight exposure (SE) subjects aged 14-32 years
P
0
SKIN COLOR VARIATION AMONG PAPUA
29
1
411
I
Fig. 1. Variation with age of mean percentage of reflectance at 685 nm from the inner, upper
arm. Vertical bars represent 2 1 SE.
phase. To test this hypothesis the linear
regression of individual reflectance values on
age was calculated for two age groups, 2.014.9 years and 15-69 years. Menarche occurs
at 15.6 years among the Karkar Islanders
and 16.5 years among the villagers of Lufa
CHarvey, 1974);therefore, the age cohorts selected give a good approximation to pre- and
postpubertal stages of development.
The regression and correlation coefficients
are given in Table 3. Within each age grouping there are no significant differences between sexes or between populations in the
slope of the linear regression equations.
However, with the exception of the Lufa male
samples, there are large and significant differences in slope between the regression lines
for the pre- and postpubertal groups. The percentage of the total variation accounted for
by the regression is generally higher in the
older than in the younger group, reaching
14.4%in the sample of Lufa males over 15
years of age.
Exposure to sunlight
The incidence of exposure t o sunlight for
the four samples in the direct observation
study is given in Table 4. The men and
women of Lufa were observed for a longer
period than were those of Karkar, although
the Karkar people had records compiled for
a minimum of 120 hours. During their total
daily activity the Lufa villagers spent nearly
twice as long, on average, in the sun as the
R.G. HARVEY
412
I...
28 -
ia
16
I
.
5
.
.
10
I
.
15
,
.
20
I
25
35
45
55
>60
Age ( y r s )
Fig. 2. Variation with age of mean percentage of reflectance at 685 nm from the forearm.
Vertical bars represent +_ 1SE.
Karkar Islanders. Figure 3 shows the percentage of time spent in sunlight for hourly
intervals throughout the day. It illustrates
the substantial differences in exposure times
between the two populations. Incidence of
exposure is very similar among the men and
women of Lufa, especially during the midday
period when the sun is at its highest elevation. In contrast, the men of Karkar were
more exposed to sunlight than the women
during the period 12.00-15.00 hours. The
pattern of exposure variation in the Karkar
women suggests some measure of active
avoidance of sunlight from midday until
midafternoon.
potheses, none of which are likely to be
mutually exclusive. There may be host differences in the capacity of the skin to synthesize melanin, to transfer it to the
keratinocytes of the epidermis, and to maintain it in response to UVL exposure, the socalled tanning capacity of the skin (Harrison
and Owen, 1967). There may be geographical, seasonal and altitudinal variation in the
intensity of erythemally effective natural
UVL (Robertson, 1969). Duration of daily exposure to UVL and the shielding effect of
clothing must also be taken into account,
together with genetically determined differences in cutaneous pigmentation.
Skin site differences
The skin site, sex, and population differ- The contrast between upper arm and foences suggest several explanatory hy- rearm reflectance shown in Table 2 is probaDISCUSSION
413
SKIN COLOR VARIATION AMONG PAPUA
TABLE 3. Linear regression and correlation coefficientsfor the relationship between
'ualues) and age (X ualues) for the forearm
percentage of reflectance at 685 nm 0
Age groupipopulation
2.0-14.9 years
Karkar (M)
Karkar (F)
Lufa (Mf
Lufa (F)
15.0-69.0 years
Karkar (MI
Karkar (F)
Lufa (M)
Lufa (F)
Regression coefficients
b SD
Correlation
(r)
N
a
158
170
92
103
26.4
28.8
27.1
28.5
-0.237 +_ 0.066
-0.287 k 0.066
-0.297 +_ 0.113
-0.387 t 0.101
-0.278
-0.316
-0.266
-0.356
238
256
209
255
25.0
26.9
22.2
23.0
-0.083* k 0.014
-0.089" +_ 0.014
k 0.015
-0.090
-0.058** f 0.018
-0.354
-0.338
-0,385
-0.193
'P< .05,*'P< ,002, for slope differences between age groups, within populations.
90 -
- 80
-
70-
t
z 60-
u)
0
2
w
40 50
c.
s
.F 30 -
;2 0 10 C
1
0
1
1
7
8
9
I
10
I
I
.
I
11 12 13 14
Hour of Day
1
I
I
I5
16
17
I
18
Fig. 3. Average hourly incidence (C)
of exposure to sunlight for 26 males and 30 females of
Karkar and 29 individuals of each sex at Lufa.
TABLE 4. Incidence of exposure to sunlight during daily activities
(auerages of all obseruations)
Observation
period ( m i d
% Time in
Sex
N
Karkar
Males
Fema1es
26
30
8,538
7,231
40.3
38.0
Lufa
Males
Females
29
29
34,361
27,559
76.0
76.6
Place
sunlight
414
R.G. HARVEY
bly due to two main factors. The first is a
difference in the density of epidermal melanocytes in the inner upper arm compared with
the forearm and thus in the tanning capacity
of the two sites. Regional variations in melanocyte density over the body are well documented (Szabo, 1967), although there are no
specific data of the type reported by Garcia
et al. (1977, 1981) for the Solomon Islanders
available for the inhabitants of Karkar Island and Lufa subdistrict. Secondly, there is
a difference in the frequency and intensity of
exposure to UVL resulting from the more
sheltered anatomical position of the inner
upper arm surface and, in certain cases, from
the shielding effects of clothing. Skin site
differences are a n established feature of reflectance studies on human populations (Ojikutu, 1965) and there are numerous reports
of within-sex, within-population differences
in percentage of reflectance from upper arm
and lower arm sites (Leguebe, 1976).
Tournel (1966),and Rigters-Aris (1973).Similar results have been obtained for the present study. Although there are some time-ofday differences in sunlight exposure for Karkar men and women (Fig. 31, there are no
substantial within-population, within-sex
differences in average exposure times (Table
4). Therefore, it is felt justifiable to propose a
difference in tanning capacity to explain the
contrast between male and female reflectance values, which are clearly demonstrated
by both populations. The evidence that this
contrast is largely independent of UVL exposure rates suggests that it may be a n example of genetically determined sexual
dimorphism.
Population differences
The significant difference between Karkar
and Lufa skin reflectance, which is so much
more pronounced on the forearm than the
upper arm, suggests that a combination of
greater daily exposure to sunlight and higher
Sex differences
W L intensity in the highland environment
To elucidate the contrast between Karkar may be responsible. This hypothesis finds
and Lufa in the sex differences on the upper support in the observations of sunlight expoarm, two environmental factors have been sure (Table 4; Figure 31, which show marked
examined the shielding effects of clothing contrasts between the coastal and highland
and differential exposure to UVL. Villagers people. It is also supported by the observaof the coastal and highland communities had tions of Robertson (unpublished Ph.D. thesis,
conspicuously different clothing habits. All 1974) who demonstrated that under clear
of the Karkar Islanders wore some form of conditions at midday there is a n increase of
Western-style clothing, which included shirts about 20% in the sun-tanning effectiveness
and blouses with sleeves that covered all or of W L for every 1,500 m increase in altipart of the upper arm. Lufa clothing styles tude. This means that in the absence of macontrasted markedly with those of Karkar. jor climatic differences affecting UVL
Very rarely were individuals observed with intensity at the two localities, the sun-tanWestern-style clothes. Virtually all the vil- ning effectiveness of the midday sun a t Lufa
lagers were clad traditionally in a simple would be about 23%greater than at Karkar,
arrangement of woven bark cloth hanging where none of the villages studied were more
from a broad belt around the waist. Clothing than 150 m above sea level.
was rarely worn on the upper part of the
Geographical variation in the strength of
body and the opportunity for solar UVL to erythema-producing wavelengths of solar
reach the upper arm during outdoor activi- W L has not been investigated in Papua New
ties was high in the Lufa population, espe- Guinea. However, data for seasonal fluctuacially during heavy manual work in the tions in intensity of these wavelengths have
unshaded gardens. The upper arm reflec- been obtained for Goroka in the Eastern
tance values for the Lufans thus represent, Highlands District (about 60 km from Lufa)
to a much greater extent than those of the (Robertson, unpublished Ph.D. thesis, 1974).
Karkars, the characteristics of facultative, as These data indicate that during the two seadistinct from constitutive, skin color.
sons in which the skin reflectance fieldwork
Sex differences in the tanned skin of UVL- was conducted (February to June on Karkar,
exposed surfaces, such as the forearm and July to October at Lufa) average levels of UV
forehead, have been reported for a number of radiation would have been similar for a given
native peoples in tropical habitats; among altitude. Seasonal climatic differences affectthe reports are those of Barnicot (19581, ing the absolute potential for sun-tanning
Walsh (19641,Huizinga (1965,1968),van Rijn- are therefore unlikely to be responsible for
SKIN COLOR VARIATION AMONG PAPUA
the observed population differences in forearm melanization, and it seems reasonable
to conclude that the marked differences in
exposure to sunlight and differences in UV
intensity associated with altitude are the
principal factors involved.
Age changes in melanin pigmentation
In upper arm reflectance, the between-population differences (Fig. 1)can probably be
accounted for by the cultural differences in
clothing between coastal and highland peoples, as already discussed, and by the field
observation that during the life span of the
Karkar Islanders their clothing habits
change in a manner that influences the UVL
exposure of the upper arm.
At the time of the survey most of the Karkar children went about stripped to the waist,
but around puberty both boys and girls
adopted a preference for wearing shirts or
blouses, many of which had sleeves that covered the top half of the upper arm. These
clothing styles continued during adulthood
but became more variable during later years
when clothing above the waist was frequently discarded during work in the gardens. This may be a n important contributory
factor in the postpubertal increase in upper
arm reflectance, which can be considered, at
least in part, as a manifestation of the UVL
screening effect of upper arm clothing worn
during early and middle adulthood.
The numbers of Lufa children in the youngest age groups are small; however, the results suggest that during early childhood
their upper arms are lighter than those of
the Karkars. Further research is needed
along lines similar to the ultrastructural
studies of skin pigmentation by Garcia et al.
(1983) to determine whether differences in
melanocyte packaging of the keratinocytes,
such as those found between Bougainville
and Malaita Islanders, also occur among the
genetically different populations of coast and
highlands in Papua New Guinea. Such histological differences might affect age variation in measurements made by reflectance
spectrophotometry. Whatever the cause of
the observed differences, the age changes in
upper arm reflectance at 685 nm in the Lufa
villagers are unlikely to be the same a s those
of the Karkars owing to the virtual absence
of upper body clothing worn at Lufa, the lack
of shade in the highland gardens, and the
high daily exposure to W L in the highland
environment.
415
With regard to age changes in the melanin
pigmentation of the forearm skin, a tendency
for mean percentage of reflectance at 685 nm
to decrease with age on exposed skin surfaces
was noted by Walsh (1964) in a study of
Papua New Guineans from Mt. Hagen (Western Highlands District). A similar result has
been found in the present study, but the main
interest here is that the darkening process is
more rapid before puberty than after. This is
almost certainly due to endocrine changes
(Conway and Baker, 1972; Kalla, 1973; Kahlon, 1976) superimposed on the cumulative
changes in the melanin pigmentary mechanism resulting from frequent exposure to
UVL (Quevedo et al., 1975; Mitchell, 1963).
The latter can be expected to continue
throughout the lifetime of the individual and
probably accounts for the gradual and progressive increase in melanin pigmentation
with age in adults of both populations.
ACKNOWLEDGMENTS
The author is indebted to Professor G.M.
Budd (Sydney) for supplying sunlight exposure observations for the people of Karkar
and Lufa and for his helpful criticism of this
manuscript. The assistance of Dr. Leigh Hendrie (Sydney) in the collection of sunlight
observations is gratefully acknowledged.
Thanks are due to Dr. Bill Craig (Canberra)
and Miss Kay Shaw (London) for their help
with programming and computing. Dr. Don
Robertson (Brisbane) generously gave advice
and information on the measurement of erythemally effective W L . The inspiration and
encouragement of the late Prof. R.J. Walsh
(University of New South Wales) is very
greatly appreciated. The author is grateful
to Dr. Anthony J. Boyce (Oxford) for helpful
comments on this manuscript.
The fieldwork was supported by the Australian Academy of Science and the Royal
Society (London). It was part of the joint Australian-UK H A W P project in Papua New
Guinea.
LITERATURE CITED
Barnicot, NA (1958)Reflectometry of the skin in Southern Nigerians and in some mulattoes. Hum. Biol.
30:150-160.
Boyce, AJ, Harrison, GA, Platt, CM, Hornabrook, RW,
Serjeantson, S, Kirk, RL, and Booth, PB (1978)Migration and genetic diversity in an island population: Kar
Kar, Papua New Guinea. Proc. R. Soc. Lond. Ser. B.
202~269-295.
Budd, GM, Fox, RH, Hendrie, AL, and Hicks, KE (1974)
A field survey of thermal stress in New Guinea vil-
416
R.G. HARVEY
lagers. Phil. Trans. R. Soc. Lond. B. 268:393-400.
Byard, PJ, and Lees, FC (1982) Skin colorimetry in Belize. 11. Inter and intra-population variation. Am. J.
Phys. Anthropol. 58~215-219.
Conway, DL, and Baker, PT (1972) Skin reflectance of
Quechua Indians: The effects of genetic admixture, sex
and age. Am. J. Phys. Anthropol. 36:267-282.
Garcia, RI, Mitchell, RE, Bloom, J, and Szabo, G (1977)
Number of epidermal melanocytes, hair follicles, and
sweat ducts in skin of Solomon Islanders. Am. J. Phys.
Anthropol. 6Ot323-326.
Garcia, RI, Mitchell, RE, Bloom, J, and Szabo, G (1983)
Solomon Islander skin pigmentation: Ultrastructural
differences related to genetic variation in Melanesia.
Am. J. Phys. Anthropol. 60:323-326.
Garcia, RI, Richardson, RE, and Szabo, G (1981) Skin
colour variation in Solomon Islanders: Reflectometry,
histology and ultrastructure. In M. Seiji (ed): Pigment
Cell 1981: Phenotypic Expression in Pigment Cells.
Tokyo: University of Tokyo F’ress, pp. 199-206.
Harmse, NS (1964) Reflectometry of the bloodless living
human skin. Proc. Kon. Ned. Akad. v. Wetensch. C.
67t138-143.
Harrison, GA, and Owen, JJT (1956) The application of
spectrophotometry to the study of skin colour inheritance. Acta Genet. 6~481-485.
Harrison, GA, and Owen, J J T (1964) Studies on the
inheritance of human skin colour. Ann. Hum. Genet.
(Lond.)28:27-37.
Harrison, GA, and Owen, JJT (1967) Skin colour in
Southern Brazilian populations. Hum. Biol. 39:21-31.
Harvey, RG (1974) An anthropometric survey of growth
and physique of the populations of Karkar Island and
Lufa subdistrict, New Guinea. Phil. Trans. R. SOC.
Lond. B. 268:279-292.
Hornabrook, RW (1977) Human adaptability in Papua
New Guinea. In GA Harrison (ed): Population Structure and Human Variation (International Biological
Programme 11). London: Cambridge University Press,
pp. 285-312.
Huizinga, J (1965) Reflectometry of the skin in Dogons.
Roc. Kon. Ned. Akad. V. Wetensch. C. 68:289-296.
Huizinga, J (1968) Human biological observations on
some African populations of the thorn savanna belt.
Proc. Kon. Ned. Akad. V. Wetensch. C. 71:356-390.
Kahlon, DPS (1976) Age variation in skin colour: A study
in Sikh immigrants in Britain. Hum. Biol. 48:419-428.
Kalla, AK (1973) Ageing and sex differences in human
skin pigmentation. Z. Morphol. Anthropol. 65:29-33.
Leguebe, A (1976) Catalogue of spectrophotometric data
on skin pigmentation. Part one: 1958-1973; A: Reflectance at nine wavelengths. Documents de travail, Inst.
R. Sci. Nat. de Belgique 9:l-25.
Mitchell, RE (1963) The effects of prolonged solar radiation on the melanocytes of the human epidermis. J.
Invest. Dermatol. 41,199-212.
Norgan, NG, Ferro-Luzzi, A, and Durnin, JVGA (1974)
The enerev and nutrient intake and the enerm expenditure-f 204 New Guinean adults. Phil. Tra-is. R.
SOC.Lond. B. 268:309-348.
Oiikutu. 0 (1965) Die Rolle von H a u t t i m e n t und
“Schwelszdriisen in der Klimaanpassung degMenschen.
Homo 16:77-95.
Quevedo, WC, Jr, Fitzpatrick, TB, Pathak, MA, and Jimbow, K (19751 Role of light in human skin colour variation. Am. J. Phys. Anthropol. 43t393-408.
Rigters-Aris, CAE (1973) Reflectometrie cutanee des Fali
(Cameroun) Proc. Kon. Ned. Akad. V. Wetensch. C.
76:500-511.
Robertson, DF (1969) Long term field measurements of
erythemally effective natural ultraviolet radiation. In
F Urbach (ed): The Biologic Effects of Ultraviolet Radiation. Oxford: Pergamon, pp. 433-436.
Serjeantson, S, Kirk, RL, and Booth, PB (1983) Linguistic and genetic differentiation in New Guinea. J. Hum.
Evol. 12:77-92.
Szabo, G (1967) The regional anatomy of the human
integument with special reference to the distribution
of hair follicles, sweat glands and melanocytes. Phil.
Trans. R. SOC.Lond. B. 252:447-485.
van Rijn-Tournel, J (1966) Pigmentation de la peau de
Belges et d’Africains. Bull Soc. R. Belge. Anthropol.
Prehist. 76:79-96.
Walsh, RJ (1964)Variation in the melanin content of the
skin of New Guinea natives of different ages. J. Invest.
Dermatol. 42:261-265.
Документ
Категория
Без категории
Просмотров
0
Размер файла
702 Кб
Теги
factors, color, papus, variation, skin, among, guineans, new, ecological
1/--страниц
Пожаловаться на содержимое документа