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Blood groupings and racial classification.

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BLOOD GROUPINGS AND EACIAL CLASSIFICATION
R. RUGGLES GATES
King's College, Universiiy of London, England
The blood groups are simply an additional means of comparing races. They are definite and fixed units, whose method
of inheritance is known and whose descent can be traced. As
indices of racial relationships they have a great advantage
over physical measurements ; for the latter are not only quantitative and subject to fluctuations, but very little is known of
the manner of their inheritance. The relation of the cephalic
index or the nasal index to genic differepces is largely a matter
of conjecture, and much more needs to be known of the inheritance of head shapes before any very definite meaning
can be attached to differences in cranial measurements.
The blood groups appear to be typical genic mutations, and
as such must follow the general laws of mutations. The use
of the blood groups in connection with racial differentiation
and relationship must then be based upon the theory of mutations, and I have shown elsewhere (Gates, '36 a) that the
theory of mutation frequencies can be developed further in
connection with the study of the blood groups and their racial
distribution.
Like other mutations, the blood groups must arise repeatedly, and the evidence appears to be best interpreted on the
hypothesis that A and B have arisen as dominant mutations
from 0, which would then represent the primitive condition.
If this is true, we must assume that A and B have arisen in
the same way in anthropoids, as parallel mutations. There
is no difficulty about this, because it is now recognized that
l P a p e r read before the Section of Anthropology at the Oalcutta meeting of the
Indian Science Congress, January, 1938, a8 a delegate from the British Asaociation and the American Association f o r the Advancement of Science.
385
A X E R I C A N J O U R N A L O F PHYSICAL ANTHROPOLOOY, VOL. XXIV. S O .
JANUARY-MARCH, 1939
3
386
R. RUGGLES GATES
parallel mutations in related species or groups are of frequent
occurrence, and it seems evident (Gates, '36 b) that they have
played a more important role in evolution than has yet been
recognized. As regards anthropoids, the fact that of seventysix chimpanzees tested seventy-one were A (= 93.4%), only
five 0 and none B, indicates that the distribution differs in
important respects from what has been observed in man,
although pure Blackfeet Indians showed 76.5% A.
Not only do particular mutations recur with a particular
frequency which is characteristic, the frequency being much
higher with some mutations than with others; but we must
also assume that at times mutation rates change, and that new
mutations begin to appear, for otherwise there would be no
evolution, or at any rate no differentiation. We have a t present little d e h i t e evidence regarding changes in mutation rate,
although it is necessary to assume that such changes occur.
The Amerindians of Darien, who produce a high percentage
of albinoes in every generation, appear to be most reasonably
interpreted as a case of a greatly increased mutation rate;
and in the Blackfeet and related tribes of Indians in Western
Canada, which have a very high percentage of the A blood
group (hlatson and Schrader, '33)' this condition may have
been produced by a great increase in the A mutation rate.
The evidence suggests that the frequency of the A and B
mutations may be of the order of perhaps 1in 100,000.
I n comparing the blood groups of different peoples and explaining the differences which arise between types occupying
different areas, it is necessary to take into account not only
migration and interracial crossing but also the occurrence of
fresh mutations with a rate which is probably characteristic
of each racial type over considerable periods. The blood
groups appear to be quite non-selective in themselves, although
they might conceivably be genetically linked to some racial
character or condition which is selective. The distribution of
A, B and 0, however, in various races leads one to conclude
that they are probably entirely non-adaptive in nature. If
this is the case, the rate of spread of the A or B will depend
BLOOD OROUPINQS AND RACIAL CLASSIFICATION
387
entirely on their mutation frequency. As pointed out earlier
(Gates, '36 a), the B mutation seems to have begun to appear
at a much later period than the A, and A is therefore spread
much more widely through the primitive races surviving to
the present time.
The statistics of blood grouping make it probable that the
B mutation has never appeared in such peoples as the
Australian aborigines, the Bushmen of South Africa and the
Basques of Europe, which have a high percentage of A while
their very low percentage of B has probably come in through
crossing. The American Indians have long been regarded as
having aboriginally only the 0 blood group. But more recent
results indicate that certain tribes in Western Canada are
much higher in A than are Europeans. They can therefore
not have derived their A from such a source. These tribes
form a group in Western Canada east of the Rocky Mountains,
including the Blackfeet and Bloods, the Beavers and other
tribes on the Peace River, the Slaves and Dogribs in the
southern part of the Mackenzie basin. F o r this purpose I am
permitted to quote some unpublished results of Dr. J. C. B.
Grant, as well as published results of his and Matson's and
mine. Surrounding this area high in A (40 to 76%) are the
Stony (Assiniboine) Indians with 30.8% A, the Chipewyan
and Yellowknives with about 24% ; and the Crees on the East
and Loucheux on the North with apparently no original A.
On the agreed hypothesis that America was originally populated from across Behring Strait in post-glacial times, the
fact that the Indians of pure blood showed neither the A nor
the B blood group was somewhat anomalous. From the recent
results we may assume either that a center of the A mutations
arose in this part of Western Canada, or that the tribes with
40% or more of A are descendants from an original people
migrating from Asia and already having, like many other
primitive peoples, a high percentage of A. The latter hypothesis is perhaps less probable, because the more northern tribes
such as the Loucheux, and the British Columbia coastal
Indians (Gates and Darby, '34) which are in the path of a
migration from Asia, both appear to be originally without A.
388
R. RUGGLES GATES
Another difficulty in accounting for the high percentage of A
is that the Blackfeet are Algonkian Indians while the Beavers,
Slaves and Dogribs are Athapascans, and the Stonies are
classed with Siouan tribes. The latter are "to some extent
amalgamated with Cree" (J.C. B. Grant in litt.), which would
reduce their percentage of A.
Jenness ('37) has recently shown good reason for concluding that the Algonkian tribes were the earliest arrivals in
America. Among these people he includes the Micmacs, who
(Gates, unpubl.) were probably 0 before crossing wit.h Europeans began. The Athapaskans, if they came later, might
have brought the A blood group with them. But there are
difficulties with this view, as already pointed out, and the fact
that the Blackfeet and Bloods, which are high in A, belong to
the Algonkians, favors the conclusion that a fresh center of
the A mutation arose on the American continent.
Other recent evidence bearing on this question is supplied
by the examination of mummies and skeletons excavated in
America. Matson ('36) examined sixteen such mummies by
absorption methods and concluded that they were all 0, while
Boyd and Boyd ( '37) find among 196 mummies 2% A, 3.6% B
and 1% AB. The latter results are so improbable on general
grounds that these data can only be accepted when the accuracy of the method has been confirmed. Candela ('37) has
recently examined six excavated early Indian skeletons and
concluded that five of them were A and one 0. If these tests
are reliable they would of course show that a high percentage
of A existed in the early aboriginal population of America,
but we must wait for further evidence.
The great number of racial types in India and adjacent
lands makes this a fertile area for the study of blood-grouping,
and already results of much interest have been obtained. The
Paniyans of the Wynaad Plateau have 62.4% of A (Aiyappan,
'36), which confirms the relationship of these pre-Dravidian
people to the Australian aborigines and contrasts strongly
with the 26.7% of A in the adjacent Maharattas of Goa. The
Tibetans of Gyantse (Gates, '36c) on the eastern border of
BLOOD GROUPINGS AND RACIAL CLASSIFICATION
389
Tibet are extraordinarily low in 0 and high in AB, a result
which may be accounted for by crossing of an A people with
the Chinese high in B.
Work which is still in progress in Assam indicates that the
various racial types of the Naga Hills can be distinguished by
their blood group ratios. The results so f a r obtained at
Kohima by Doctor Vieyra and at Mokokchung by Doctor
Kundu under the general direction of Mr. J. P. Mills, appears
to support the latter’s conceptions of the relations between
these native peoples. Thus he concludes on general grounds
(in litt.) that the Konyaks are ‘older,’ i.e., more primitive,
than the Angami, and this is confirmed by the higher percentage of 0 and A among the Konyaks and their lower percentage
of B. Again, he concludes that the Konyaks and Aos have
much in common, and the fifty-seven Aos hitherto bloodgrouped indicate considerable similarity although they appear
to be somewhat lower in A and higher in B. That the Thado
Kuki are an entirely different race is confirmed by their extremely low frequency of 0 and the fact that they are highest
of all in B and AB.
Finally, I should like to point out that no country in the
world is likely to surpass India in the interest of its blood
group results. This being the case, it is desirable that the
work of blood grouping be organized in different parts of the
country and that a concerted effort be made to obtain from
each racial type a sufficient number of blood tests to constitute
a statistically significant sample of each population. This is
a work in which anthropologists can cooperate with medical
workers and others in making the necessary tests, but it is
all-important that the results be of the utmost accuracy and
that every possible source of error be eliminated.
390
R. RUGQLES GATES
LITERATURE CITED
AXYAPPAN,
A. 1936 Blood-groups of the pre-Dravidians of the Wynaad Plateau,
India. Man, XXXVI, 191-194.
BOYD,WILLIAM C., AND L. G. BOYD 1937 Blood grouping tests on 300 mummies
with notes on the precipitin test. J. Immunology, XXXII, 307-319.
CAXDELA, P. B. 1937 Blood group determination upon Minnesota and New Pork
skeletal material. Am. J. Phys. Anthrop., XXIII, 71-78.
GAmS, R. Rnaoms 1936a Recent progress in blood group investigations.
Genetica, XVIII, 4745.
1936 b Mutations and natural selection. Am. Naturalist, LXX,
505-516.
1936c Tibetan blood groups. Man, XXXVI, 110-111.
1939 The blood groups and features of the Micmac Indians. J.
Roy. Anthrop. Inst. ( I n press.)
GATES,R. R., AND G. E. DARBY 1934 Blood groups and physiognomy of British
Columbia Coastal Indians. J. Roy. Anthrop. Inst., LXIV, 2344.
JENNESS, D. 1937 Tha Indian background of Canadian history. Canada Dept.
of Mines and Resources (Nat. Museum of Canada), Bull. 86 (Anthrop.
series no. 21), p. 46.
MATSON,G. A. 1936 Blood-grouping of mummies. J. Imrnunol., XXX, 459-470.
1933 Blood grouping among the ‘BlackMATSON, 0. A., AND H. F. SCHRADER
feet’ and ‘Blood’ tribes of American Indiana. J. Jmmunology, XXV,
155-163.
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