The Mrabri : Anthropometric Genetic, and medical examinations. พิมพ์ อีเมล
เขียนโดย gebhard Jlatz   



                                  MEDICAL EXAMINATIONS

                                              Gebhard Flatz


           The   second   Mrabri (1 )  expedition  of   the   Siam  Society   gave

the  author  of   this  report  an  opportunity   to  examine  somatometrical-

ly  and  medically  18 of  the  24  Mrabri  encountered  at  the  Meo village
Ban   Khunsathan    ( Nan Province )   in   January    1963.    The   examina- 

tions  were  carried  out  with   the   purpose  of  augmenting  the  general 

knowledge  of   the  Mrabri   people  by  a  more  complete  description of

their    physical   features,   of    pathologic   conditions,   and   of   genetic  

characteristics,   such   as   blood   groups,   hemoglobin   types  etc.  Fur-

thermore,  it  was  attempted  to  aid  in  clarifying  some  of  the questions

raised   by    previous   reports   concerning    the so — called   Phi   Tong

Luang  and  by  the  findings  of  the  first  Mrabri  expedition  of the  Siam

Society,  reported     by    the    leader   of   both   expeditions,   Mr. Kraisri

Nimmanahaeminda,    and    Mr. Hartland-Swann  (2) :   Are     the    Mrabri 

an  ethnic  and racial  unit  or  are  they a group thrown together in  recent

centuries  by  a  caprice  of   fate ?  Do   they   show  the  expected  criteria

for  people  who  have  been  called    " autochthonic  stock  of  Southeast

Asia"   (Condominas)  and  " protomongoloid "  ( Bernatzik ),  or  do  they

exhibit   things   in  support   of  the  legend  of  the  prince   of   Nan  who 

released  his  slaves  into  the  jungle?  And finally,  is  there any  truth  in

the   tales  describing   the  forest   people  as   " negritoes ",  tales  which

have  entered  a  recent  ethnologic  publication(3).


            Beforethe  results  of  the  examinations  are  presented   it  should
be mentioned  that  the  author  of  this  report  is  a physician  with  train-
ing   and  experience  in   hematology   and   population  genetics.    Some
of  the  examinations  were  carried  out  in  specialized  laboratories,  and
for  the  evaluation  of  some  of  the  results  expert  advice  was  sought.
Due  mention  will  be  made  in  the  appropriate  places.





 162                                       Gebhard Flatz

                                 Results and Comments (4)

              A. Physical description.

              Eight   individuals  of   the   group   of   Mrabri  examined   were
members  of  the  group  encountered   by   the  first  expedition   in    1962.
Therefore, little  has  to  be  added  to  the  apt  description of the physical

appearance   by   Kraisri   Nimmanahaeminda   and   J.  Hartland-Swann (2).
Several   points  have  to  be  stressed  because   of    their  importance   in
judging   the   homogeneity  and  the  racial  classification  of   the  Mrabri.

The   shortness  of   stature,   the  muscularity  of   the  body,  and
the  difficulty  of  estimating  their  age  will   be   mentioned  again   under
"  physical examination "   and   " somatometrics  ".   Conspicuous  is  the
relative   similarity  of    the    build   of   the   face,  characterized   by   pro-
nounced   supraorbital  ridges  (brows);  prominent   cheek-bones   which
give  the   face   below   the   eyes   a    triangular   configuration;   almond-
shaped  eyes  with  a  laterally   elevated  ( "mongoloid" )   lid  axis.  There
is,  however,  no   or   only  a  hint  of  an  epicanthal  fold,  the characteris-
tic   of  the  mongoloid    eye  
sensu  strictiori  ( as  seen,  for  example,   in
Chinese).   The    nose    exhibits   the   most   distinctive   features.   It   is
straight,  rather  low  in  height,  very  wide  at   the  base,  and  does   not
protrude   much   from   the   facial   plane.   This  nasal   configuration   is
most   conspicuous   in   comparison   to  Europeans,  but  there  are  also
differences    in    comparison    with   both   Thai   Nuea   and   Meo   (see
somatometrics ).

 Comment :  The  similarity  of    the physical   features  indicates
a  common  genetic  background  of  the  members of  this group. This is
in  contrast  to  the impression gained  at  the  first  Mrabri expedition
Some   medical   observations   may   explain   the  difference  of opinion.
The  features  of  one  member  of  the  group   differ  considerably  from
gros,   giving   the   impression   of    a   completely    different  type
(Fig. 1 ).     This   man's  facial  configuration   with   laterally   depressed
lid    axis  ( "antimongoloid" ). squint,  beaked  nose, and  receding  chin,
is  characteristic  of  a   hereditary  malformation  of  the   facial  skeleton,
dysostosis   mandibulofacialis.  In  other   members of  the  group  differ-
ences  in  the  length  and  style  of  scalp hair,  in skin texture, a  relative









coarseness   of   the  features   in  some  men,  and   squints  and  corneal
tend   to   increase  the  variance.   They   cannot  obscure  the
   of   the   facial   and   cranial   configuration   of   most   of   the
  of  the  group (Fig. 2).


B. Somatometrics.

The  measurements  obtained  from  15  Mrabri  men  are  given in
  I.  The  short  stature,  the  broad  face,  and   the  short  wide  nose
reflected   in   these  measurements.   The  generally  small   standard
  is  an  indication  of  the  uniformity  of  the  group.


Table  II  shows   a   comparison   of    the  somatometric   indices
 for   the   Mrabri   and   three  control   groups,    Thai   Nuea,
  and   Germans.  All  indices  were  calculated   from  measurements
  by    the  same   examiner   and    the   same  technique.  The  nasal
  do   not   conform    with    the   standard  indices.  Nasal   length
to  be  substituted  for  nasal  height because of  the  limited instrum-
  at  hand.


The   cephalic   index  ( breath  of   the  head   in   percent  o f  the
length )
  shows  the  Mrabri  to  be  mesocephalic,  only  two  are   in   the
  ranges  of  brachycephalic.  In  contrast,  the  Meo  and   Northern
  are   predominantly   brachycephalic.    The   variability   in    these
  is,  however,  much   greater  than   in    the   Mrabri.  The    facial
  show  little  difference  between  Mrabri  and  Thai  Nuea   ( both
  broad-faced  with  indices  near  80),  as compared  to the  Europeans
  high  and  narrow  faces.  The  nasal  indices  are  similar  in    mean
  range  for  Thai  Nuea  and  Meo,  whereas  Mrabri  and   Europeans
  nasal   antipodes.  Fig.   illustrates   the   different  nasal  configura-
  It   is   apparent   that   the   Mrabri  have  the  largest  nostril  area
  circumference  of  the  four  populations


Lateral   photographs   of   the   Mrabri   showed  a    pronounced
  of   the  face  typical  for   mongoloids  (Fig. 4.)    The   projected
  from  the  cornea   to   the  nasal  apex  was  near 3  cm   for   the
  as  compared  to  4  to  cm  in  Europeans.

Comment :  Somatometric   data  and  photographs  were   submit-
  to  Doz.  Dr.  H.  Walter   of the   Anthropological  Institute    of   the







164                                              Gebhard Flatz


University  of  Mainz.  He  concurred  with  the  opinion  that  the  Mrabri
are  distinctly  mongoloid.  They  show  many  characteristic  of  the  type
described    by   von   Eickstedt(5)   as   palaeomongoloid.   According   to
von  Eickstedt  the  palaeomongoloid  race  was  present   in   the  ancient
population   of   the   Southeast   Asian   subcontinent.   Historically   later
it  was  separated   by  migrations  from  the  North.  The   Mrabri   could
be   a    small   relic   of    persons    predominantly   palaemongoloid.   Dr.
Walter   believes,   however,  that  they  show  some  admixture  of   diffe-
rent   origin,  possibly   sinid.  The  surprising  uniformity   of   the   Mrabri
is  thought  to be  due  to  endogamy, i.e.  marriage   limited   to   members
of  a  ethnic  or  social  group.


The  author  is  of  the  opinion  that  the  palaeomongoloids    have
contributed   much    to    the   composition   of   the  present     "immigrant"
populations  of   Southeast   Asia.   Palaemongoloid   types   are   frequent
in  the  Wa
(6),  Lawa ( Fig. 5 ),  Khmer,  and  also  in   the  Thai  population.
The  most  distinctive   palaemongoloid  sign  is  the  flat  and  wide   nasal
configuration.   This   configuration   is   not    in    itself   a    racial   charac-
teristic.  It   is   found  frequently   in    populations   inhabiting  areas  with
humid,  hot  climate
. (7)


C. Physical examination.

15  members  of  the  Mrabri  group  had  a   physical  examination.
Besides  the  detection of physical anomalies  and  pathologic conditions
special    attention    was   paid   to   the   question   of   femininization   in
Mrabri  males  which  was  raised  after  the  inspection   of   photographs
taken   at    the    first   expedition.  In   the  following,  pertinent    findings
are  listed  under  organs  and  systems :


                  1.  Hair.  Thick,  straight,  and  black  in  all  persons.  Head-
         lice  were  found  in  one.   Body  hair  scanty,  no  beards.
                  2.  Eyes. Vision  could  not  be  tested   a  ccurately,  but   was
         apparently  good. Corneal   opacities    were   found   in    two   indi-
         viduals.  In   one   man   the  opacity   occupied  almost    the  entire
         cornea.  He  stated  that  an  injury  to  his   eye  was  caused by an
         insect  sting.  The  pupillar  reaction  to    light  was   prompt   in  all







                 3.  Ears.  Purulent  discharge  unilaterally  in  one  man.
                 4.  Mouth.  No   abnormalities   of    mucous    membranes    and
           tonsils.     The   teeth   were   all   in  surprisingly  good    condition.
           In   the  older  men  considerable   grinding  effects  on   the   molar
           teeth   were  noticeable.  No  trace  of   caries   or   parodontia   was

                 4.    Neck.  In   contrast   to   the   Meo   tribe    none   of     the
           Mrabri  showed  any  thyroid  enlargement.
                 5.    Lungs.  Clear   to   percussion   and   auscultation   in   all
                 6.    Heart.   Conspicuous    bradycardia   in   all   men.  Pulse
           rate  ( standing )  varied  from   44  to  62   per   minute.   This   is
           most   probably  due  to  the enormous physical  activity  of  the
          Mrabri.  In   more   sedentary  societies  a  low  pulse  rate  is con-
          sidered  a  haracteristic  of  athletes.

                7.    Abdomen.  The  spleen   was   enlarged  (2 to 5 cm below
          the costal  margin)  in  all  but  one.
                8.    Lymphnodes.    Palpable    in    the   groins    in   all    men.
         Enlargement   obviously   due    to    frequent   injuries with  infec-
         tions  on  legs  and  feet.
                9.    Genitalia.   Penis    and    testicles    were   of    normal    size.
         The   pubic  hair  was  scanty  and  limited  by  a   sharp   horizontal
         line   above    the   symphysis.   This    distribution   of   pubic   hair,
         quite  abnormal  for  Europoids,  is   normal   for   Mongoloids,  and
         was  found  in  all  Thai,  Meo,  and  Chinese  examined.

                9.    Skeletal    system.  With    one   exception,  the   man   with
         the   deformity   of    the   facial   bones   (Fig.1),  no   abnormalities
         were  found.
                10.    Neuromuscular     system.    Normal     deep    tendon    re-
         flexes.  Well-developed   muscles   of    the    extremities.   Together
         with  a  paucity  of  subcutaneous   fat   this   gives   the   Mrabri  a
         muscular   appearance.   In   comparison   to    the   Meo,   the   arm
         musculature,    particularly    the    pectoralis    muscles,   are    very






166                                                     Gebhard Fl

        prominent.    This   is   probably   due    to    frequent    climbing   of
  and  digging   in  search  of   food.  With   the   arms hanging
   pectoral  muscles  are  relaxed  and  create a  soft  prominence
  the  anterior  chest  wall  which  may   be  mistaken - especially
    photographs - for    undue   breast    development.  There    is,
   no  abnormal   amount   of    mammary   tissue  palpable
   the  suspicious   surplus  disappears  readily  when  the arms
  raised   (Fig. 6 and 7).

                11.    Skin.    The   frequent   tattoos   and   fungus    infections
        have   been   well  described  (2) Several  members   of    the  group
        had   burn   scars   on   their   back,   probably   caused  by   the  ex-
        posure to fire in the camp.
               12.   General    impression.  The   Mrabri    are   well    developed
        muscular   males.  Despite  a  paucity  of   subcutaneous   fat   there
       are   no   signs   of    malnutrition.  The   most    frequent   abnormali-
       ties   seen   to   be  fungus  infections,  burns,  and splenic   enlarge-


        It   is   difficult   to   estimate   the   age    of   the   Mrabri.  The
   members  of   the   group    were    approximately   twenty
  old  as   judged  by   the  eruption  of   only  two  third  molars
      ( wisdom
teeth ).  This   conclusion  is,  of   course,   invalid   if     the
   schedule    of   dentition    in    the    Mrabri   is    different
  that   in   Europeans. The   oldest   of   the   group    were    the
   described  below  and   one  of  the  men  who was obvious-
  older   than   the    rest,   probably    between   45   and   55.    The
  must   have   been   between   25   and   35   years  old.

       Addendum. The  only   Mrabri   female   seen   by    the   expedi-
  a   woman   of    approximately  50   years,   permitted    only   a
     examination.   She     was    obviously    ill.    A    reliable
   as   to  the   duration   and  the  nature  of  her  illness could
   be   obtained.   The   examination    revealed   a    right    middle
pneumonia  for  which  she  received  treatment.  It   is   aston-
that   this  frail   woman   who   was   quite   short  of   breath
    had    a    temperature   of    39 C   (102.2F  was   able  to  walk
hours  over  steep   mountain   paths  to our  camp   and  back.
was  reported  improved  the  next  day.







D. Blood examinations.

It   may  be  surprising  to   hear   that   we   were  able  to  collect
   of   venous  blood  from  18  Mrabri  men.   Initially,  there  was
hesitation  on   their   part  when   they  saw  the  blood  collecting
   After   the   leader   of    the    expedition,   Mr.  Kraisri   Nim-
set  an  example  by  allowing  blood  to  be  taken  from
  antecubital  vein,  the  Mrabr i were  relieved  of any suspicions and
  stoically    to   the   same   procedure.    Their  only  comment
  that  " it hurts  much  more  when  you  stick  yourself  with a thorn
  the  jungle ".

          1.    Hemoglobin concentration. (8)
                 The   concentration   of   hemoglobin  ( in  the  following  ab-
          breviated  Hb )  ranged  from  11.2  to  15.6 g/dl ( normal for adult
          males  ( 15 to 16 g/dl ).  Six  members  of  the  group  were   frank-
          ly  anemic  ( Hb below 13,5 g/dl ).

2.    Blood smears (8)
                   a )  White   blood   cells.  No   pathological   cell   forms  were
          seen.  Five  men  showed  a  moderate   monocytosis  (12  to  18%)
          which   is   frequently   seen   in   malaria.  Eight  men  had   a   mild
          to   moderate   eosinophilia   (8  to  17 %),  probably  an  indication
          of  infestation  with  intestinal  parasites.
                   b )  Blood  platelets  were  normal  on  all  smears.
                   c)   Red   blood   cells.  The morphology   of   the   red   blood
         cells   was   conspicuously  abnormal   on  several  smears.  Target
         cells   were   abnormally  frequent  on  nine  smears.   Hypochromia
         and  Anisocytosis  were  prominent.
                   d )  Parasites.  Ringforms   of    Plasmodium   falciparum,  the
         cause  of   tropical  malaria,  were  seen  on  two  smears.
         2.   Hereditary  disorders  of  the  red  blood  cells.
               For   the    non - medical   reader   a   short    introductory   note
        may  be  in  place :  Hereditary   disorders  of   the  red   blood  cells





168                                             Gebhard Flatz

         are   common   in   Southeast  Asia,  as   in  all   tropical   areas.  Ab-
         normal   hemoglobin   diseases   are   caused   by   an  alteration  of
         the  normal   chemical   composition   of   the  protein   molecule  he-
         moglobin,  the   red   coloring  matter   of   the   blood.  Besides  the
         normal  variant 
(Hb  A)  the  abnormal  Hb   E   is   present  in  5  to
         40%  of   the   population   in   different  areas   of   Thailand.   Tha-
         lassemia  is  a  disease  closely  related  to   the  abnormal  Hb  syn-
        dromes . If   the  abnormal   gene  for  Thalassemia   is   present    in
        a   person   in   the   homozygous  state  (i.e.double  dose, inherited
        from  both  parents  )   a  severe  disease  with  chronic  anemia and
        early  death  results.  Deficiency  of   the   red   blood   cell   enzyme
        glucose   6   phosphated   ehydrogenase   ( G-6-PD )  is    also  com-
        mon    in   Thailand.   In   affected   persons   ingestion   of    certain
        drugs  and   chemicals   causes   a   rapid   destruction   of   the  red
        blood  cells.

               a)  Abnormal  Hb  and  Thalasemia. ( 8 )

       Of  the  18  Mrabri  examined  six  were  heterozygous   for   Hb

       E.  One   had  an   increased  amount  of  Hb  A2   indicative  of   the
       presence  of  the  Thalassemia  gene.   The  findings   on   the   blood
       smears   were  in  accord  with  these  results.

      b) Red  cell  enzyme  G-6-PD

      Normal  activity  of  this  enzyme  in  all  18  samples.


       3. Blood groups ( 8 )

    All  18  samples   were  of   the  blood   group  A   CDe/CDe  ( A
       Rh-positive ).

       4. Virus antibodies. (8)

    In   tropical   areas    the    group  of   arthropod - born  viruses  is
      of   special   interest.   Viruses   of   this   group    cause   encephalitis
      and   dengue  f ever,   and   have   recently  been  shown   to   be   the
      causative  agent  of  Thailand  hemorrhagic  fever.

    The  blood  sera  of   the  18  Mrabri  were  tested  for  antibodies
      against  arthropod - born  viruses   at   the  Virus   Dept.   of   the 
     Component,    SEATO    Medical     Research     Laboratory,   Bangkok.







An   excerpt   of    the   report   furnished    by    Major    Halstead,   head
of    the    department,   is    given    verbatim :   The   "test   results show
a    remarkably    low    incidence    of    group    B   antibodies   and    are
essentially    negative    for     group   A.  . . . . .
   " group A "    ( of     the
arthropod - born   viruse s) "    is    represented     in    Thailand    by   at
least   one   virus,   chikungunya,   which   is   found   in  urban  areas in
decreasing    percentage    as    one    progresses    north    of   Bangkok.
Group   B   is   represented    by    the    dengue   viruses   and  Japanese
encephalitis    both    of    which   occur    widely    in   Thailand.   These
samples   show     rather     nicely   that    there   must   not   be   any   im-
portant     wild     animal     reservoir    of     these    viruses    in     remote
Thailand   or    at    least    not    at    the    altitude   where   these    tribal
people   live ".

The  visits   of   the  Mrabri   to   the   valleys   may have  been  the
occasion     for     contracting     these     virus    infections.    As     these
visits    are    infrequent    and    short    the    chance   for    infection    is
small    and    this    is    reflected    in    the    paucity    of    immunization
against   these   viruses.

5. Syphilis. ( 8 )

This    venereal    disease    is    not   uncommon    in    most    urban
societies.  Lately,    it    is    found    in    increasing   frequency     in    the
more     enterprising      tribal      groups     of     Northern     Thailand  
Considering   the   seclusion   of   the   Mrabri   it    would    not    be   ex-
pected   in   them.  None  of  the  18  sera  was  positive  for  syphilis.

The    results   of    the   blood    examinations   are   summarized   in
Table III


E. Stool examinations. ( 10 )

Two    stools    were    available    for    examination.     The   consis-
tency   of   this   material   was   remarkable.    The   entire   stool    mass
was    interspersed    with    coarse   fibers   of   approximately   1/2  mm
diameter   and   4   to   7   cm   length .  This   fibrous   mass   made   the
division    of     the     fecal     material    difficult .    Microscopically   the
fibers    appeared    to    be   of  plant   origin.   Probably   they    are   in-
digestible   remnants   of   chewed   roots   which    form    part    of    the






170                                              Gebhard Flatz


food  of   the  Mrabri.  In   one  of  the  stools   eggs  of  Trichuris
trichura,  an   intestinal   parasite   were   found.   The   frequency
of  anemia  in  the  members  of the  group  makes one suspicious
of  hookworm  infestation.  The  stools  were  rather   old.   There-
fore,  hookworm  ova,  if   they   had   been   present,  may   have
hatched  before  examination.



The  life  of  the  Mrabri,  paradisical   as   it   may   look    at    first
glance  with   its   freedom   of    regimentation  and  taxation,  is   in  truth
endangered  by  many  forces.  Diseases   which   plague the  man  in  the
plains  are  also  present  in   the   Mrabri:  infection    with    malarial  Plas-
modia,  with   fungi,   bacteria,  and   infestation  with  intestinal  parasites.
Hereditary  diseases  are  present,  and  external  forces  as   fire  and   the
beasts  of  the  forest  threaten  them.  A   relative   protection   seems   to
exist  against  certain  viral  diseases  which  are  common  in  the  valleys,
and  venereal  diseases  do  not  seem  to  have  entered  the Mrabri  com-
munity.  We  know  almost  nothing  of  the  health  statu s of  the Mrabri
children  and  infants,  but  we  may  assume  that  selection   by   disease
is   rigorous,   and   only   the  fittest  survive.  Therefore,  the  Mrabri  are
well   adapted   to   their   rough  environment;  physical  vigor  and  resis-
tance to disease are essential.

With  the  knowledge gained an attempt  can  be  made to aid  in
clarifying  some  of  the problems mentioned  at  the  beginning: Are the
Mrabri  a  different  generation  of   the  people   Bernatzik  (11)  encoun-
tered  in  the  same area  in  1936?  Bernatzik's  description  of  his "Yum-
bri"  and  the  appearance  of  the  men  seen  by  us  is  similar  in  most
details.  The   major  difference,  the   absence  of   tattooing   in  Bernat-
zik's  group  and  the  frequency  of  tattoos  in  the   Mrabri   of  1963  is
superficial  in  more  than  one  sense of  this  word,  and  may be due to
more  frequent  visits  to   the   valley  in   recent  years.  Bernatzik  does
not  give  somatometric  measurements except  for  the  height  which  is
similar  to  the  height  of  the  Mrabri.  The   only   remaining   means  of
comparison  are  the  photographs.    The sole  discrepancy between his








"Yumbri” and our Mrabri  seems to  be  the  different  hair  style  which
is  shorter,  and   in   some  similar  to  the  manner  of  the  Meo  in  Ber-
natzik's   people   (11,  Fig.  60).    The   facial   characteristics  observed
in   our   group   are   present   in  all adult  males  on  Bernatzik's  photo-
graphs.   The   prominent  brows,   the mongoloid  eyes without epican-
thal   fold,   the   straight,   wide,   and   flat   nose,   and   the  triangular
configuration  of  the  face  are  identical   in   both  groups and can  be
verified   on   Bernatzik's   figures  45,  54,  55,  and  60.   The  interpreta-
tion  of   the  evidence  gained   from   the  comparison  of the physical
features   is   in  favor   of the typological  identity of Bernatzik's "Yum-
bri''  and  the  Mrabri.   The  main  argument   in   this  question  will, of
course,  have  to  come  from  the  linguistic  investigations.


Are  the Mrabri descendants  of  a  group of slaves released into
the  jungle?   Despite  the  fact   that   one   should    not   take  historical
legends  too  lightly  it  seems  highly  improbable  that the Mrabri could
have  this  origin.   This   is  not   the  place  to   discuss the sociological
aspects  of   this  question  (can  people who have lived, even though as
slaves  in  Nan,  ever  fall  back  to  a  primitivity  as that  of  the Mrabri?).
The  results  of   the   anthropometric   and   genetic examination  cannot
exclude   this   possibility.   All   characteristics   present  in  the   Mrabri
could  have  been  present  in  a  small  founder  group  of a few  couples.
The  prince  of   Nan  is,   however,   supposed   to   have   released   two
hundred  slaves 
(2).  If   the  Mrabri  were   their  descendants  the  high
degree of  uniformity of their appearance and their blood groups  would
be   surprising   (especially   if these findings can  be  substantiated  by
examination  of  more  Mrabri  individuals).

Are  the  Mrabri  an  ethnic  unit ?  Medicine  and   anthropo-
logy  have  no  contribution  to  this  question.  The  result of  the
linguistic   and  
sociologic   investigations   will   tell  us  whether
the   Mrabri   are   a   separate   ethnic  unit.  The   clarification   of
their   linguistic   affiliation  will,  however,   be   of   great  interest
for  the  anthropologist.  If  it  can  be  proved  that their language
belongs   to   the   austroasiatic   (Mon-Khmer)   group   their  pre-
sence  in  Southeast  Asia  can  be  dated  back  2000 years.






172                                            Gebhard Flatz


The  greatest  handicap  in  the  valuation  of  the   results  of  the
examinations  of   the  Mrabri  is  the  small  number  of    individuals and
our  ignorance  of  the  size  of   the  Mrabri  population,  and   their  mar-
riage  customs.  If   the   total   number   is   indeed   not  more   than  100
(estimate  G.  Young , 9),  endogam  y  (i.e. marriage   exclusively   within
their  own   group  which  seems  to   be  customary  among  the  Mrabri)
will   lead   to  a   high  degree  of  inbreeding.  There  is,   of  course,  the
possibility  that   the  Mrabri  are  a    small,  isolated, inbred  group. This
is,  however,  not  a  plausible  explanation  for  the   fact   that   all   mem-
bers  of  our  group  belonged  to  blood  group A, a group which is  rare
in  Southeast  Asia.  This  could  only  be  explained  by a small  founder
group  in  which  by  chance  only  group  A  was present, or  by genetic
drift.   There  are,  however,  other   explanations   for  this  finding.   The
results  of   the   hemoglobin  analysis  speak  against  a   high degree of
inbreeding.  In   a  h ighly  inbred  group   with  Hb  E one   would expect
a  few  persons  homozygous  for the Hb E  gene (doubly inherited  from
both  parents).  The  absence  of   persons  homozygous  for  Hb E  from
the  Mrabri  group  may  be  due  to  a  decreased  chance for survival of
homozygous    Hb  E   carriers.    This    is    improbable.    Homozygosity
for  Hb E  causes  only  mild  anemia  and  no  disability (many  members
of  the  Armed  Forces  were  found  to  be   homozygous for Hb E).  Fur-
thermore,   it   is  likely  that  Hb E  furnishes  protection against  malaria
and  thereby  increases  the  fitness  of  the  carrier.  It is  therefore quite
possible  that   the  size  of  the  Mrabri  population  is much  larger than
expected  and   that   inbreeding  is   reduced  by contacts  with  various
groups   during    migrations.  A   selective  advantage  for  blood group
A  may  exist  under  the  environmental  conditions  of   the  Mrabri.  In-
creased   resistance   of   group   A   individuals  to  enteric  infection  is
possible  and  could  have  lead   to   the  elimination   of   the genes  for
blood  group  O  and  B  in  the  Mrabri

Racial classification.

The  application  of  the  term  "race"  to  human  populations  has
become  problematic  in  the  view  of  modern  human  genetics (12).






The  "creation" of  a race  was  often  not  more  than  the arbitrary  selec-
tion  of  a   type  of  human  and   its  designation  as the  prototype  of  a
"race".   There  is  hardly  ever  proof   that  such  a  prototype  is  not   in
itself  a  mixture  between   more   ancient  "races"  whose  existence  may
be  shrouded   in   prehistoric  darkness.  In   the  end,   the   genetic   ana-
lysis  of  race  leads  to  the  view  that  mankind  is  a  genetic  continuum.
It  is   easy   to   find   conspicuous  differences  between  people   whose
origin   is  geographically  distant  (e.g.  Chinese  and  Europeans).   Their
equally   conspicuous   similarities   prove  that  they  must  carry  a  signi-
ficant  proportion  of  common  genetic  material.  Any   division   of    the
human  species  in  races  will  inevitably  separate  large  groups of   men
who   may   be   apart   in   some  characteristic,  but  belong  together   in
others.  Therefore,  the  te
rm  race  has  not  much  scientific significance
and  is  best  restricted  to  a  descriptive  use  fo r the great,  more or less
well  defined  groups  (e.g. mongoloid, europoid, negroid).


In  1934  the  German  anthropologist  von  Eickstedt  described  a
human  type  in  Southeast  Asia  which  he  considered  characteristic of
a   palaemongoloid  race.   The  reservations  with  which   "race"  has   to
be  viewed  le t it  appear  advantageous  to  limit  the  acceptance of   the
term  "palaeomongoloid"  to  a  human  type  which  may  have  been  pre-
ponderant   in  the   prehistoric  population  of  Southeast  Asia.  We may,
therefore,  speak  of   a   palaeomongoloid    type   with   reference   to  the
three  types  described  by  H.  Liu 
(cit.a.3)  in    the  Chinese   population.
According   to   von  Eickstedt,  the  palaeomongoloids are distinguished
by   prominent   zygomas  (cheek bones),   mongoloid   eye  configuration
without  epicanthal   fold,  and  a  short,  wide ,  flat  nose,  characteristics
strongly  expressed  in  the  Mrabri, but  also   present   in  individuals  of
other  Southeast  Asian  populations  (see  comment   to   somatometrics).

The  classification  of   the  Mrabri as  protomongoloid  does not
seem   justified.  Observations   on   a   few  individuals   ( Bernatzik, 11 )
are  not  sufficient  to  create  a  new  racial  or typological class. Further-
more,  the  term  protomongoloid  induces  the  association of a common
origin  of   all   mongoloids   from   this   race,   an  assumption  which  is
neither  proved  nor  likely.





174                                            Gebhard Flatz

Are   the  Mrabri  autochthonic  in  Southeast  Asia? The  follow-
ing  remarks  to  this  problem  are  also  made  with  all  th e reservations
appropriate  for  an  analysis of observations  on a  small number of indi-
viduals.  The  somatic  analysis  leaves  no  doubt   that   the  Mrabri are
mongoloids.   No   traces   of   negrito   characteristics   are   present.   It
seems   doubtful   that   the   Southeast   Asian  subcontinent  eve r  har-
boured   a   negrito   population   north   of  the  Malayan  peninsula.The
area  of  origin  of  the  Mrabri  must  therefore be  limited  to  the area of
the  mongoloids.  The  clue  for  a  further  delimitation  may  be found in
some  somatic  characteristics  of  the  Mrabri,  particularly  in   the nasal
configuration.  The  flatness  of   the  nose  with  a   large  nostril  area  is
an   indication   of   a   domicile   in   the   tropics   for  many  generations.
There  is  good  evidence  that  the  different  nasal configurations devel-
oped  as  an  adaption  to  environmental  temperature  by selection over
many   generations.  In  cold   climates   the   narrow   nose   with    small
nostrils  conveys  an  advantage  because of the more efficient  warming
of   th e  breathing  air.   In   hot  climates  wide  flat  noses  with  a   large
nostril   area  are  preponderant.
(7)  Thus,  there  is some likelyhood that
the  Mrabri  as  a  population  are a part  of  the mongoloid  race that has
not   participated  in  the  adaption  to  colder  climatic conditions (or has
adapted  itself  to  a  hot  climate  in  the  course  of  millenniums). There-
fore,  Southeast  Asia  is  probably  their  original  habitat.

It   is,   however,  evident  from  the  somatic   measurements  that
the   present   Mrabri   show   an   admixture   of  foreign  elements,  most
likely  Lao  and/or  Meo.  The  indices   for   skull   and   nose  of   a   few
Mrabri   (No.  1 ,8,  and   14,  table I)  differ    widely   from    the   majority.
The   hemoglobin   analysis  shows,   besides   Hb E   in   six,    one   with
Thalassemia.   Hb E   has   most   probably  originated  in  ancient  South-
east   Asian  populations.   It   may    well   have    been   present   in   the
prehistoric  populations   before   the  formation of the  ethnic groupings
(Mon, Khmer etc.).  It  is  therefore  not  surprising  to   find    this  abnor-
mal  Hb   in   the   Mrabri.  Thalassemia  was,  however,  introduced   into
Southeast   Asia   later   by  Thai.  Tibeto-Burmese,  and  Chinese  migra-
tion.  Thalassemia   is   present   in   a   significant  percentage   in    most
hill  tribes  in  Northern  Thailand.  Thalassemia   may   have  entered  the







Mrabri   population   incidentally   in   recent   times.(13)    Bernatzik  (11)
relates  a  story  of  the  rape  of  a  Mrabri  woman  by   a  foreign  tribes
man.  The   combination   of   Thalassemia   and   Hb E   in   one   person
causes  a  severe  chronic  illness  leading  to  premature death  in  many
cases.  The  presence  of   both  genes   in   the   Mrabri  population will,
unfortunately,  lead  to  a  decrease  of  their  genetic  fitness.


Outlook on further Mrabri research

The   fate  of   the   Mrabri  people  appears   to     be    predictable.
Those  who  will  have  survived   the  forces  leading   to  extinction    will
finally  be  absorbed  by  the superior  hill  tribes  and  probably  later  into
the    Thai    community.     Bernatzik    (11)   claims    that     many    Mrabri
( respectively,  Phi   Tong   Luang )  have     mixed     with    the   Lahu    in
Northwest  Thailand.  The  present  author   was    unable   to  detect  any
Mrabri  characteristics   in   the   population  of  several  Lahu  villages   in
Ampoe  Fang  and  Ampoe  Wang   Nuea.   In    Ban   Doi   Khun    Sathan
there  were,  however,  several    Meo   who   differed   considerably   from
the   majority   of   their  kinsmen.  Their   facial   configuration   was   very
similar   to   that   of   the  Mrabri.  The  coming   years   will   still   provide
an   opportunity   to   study   the   Mrabri   in  their  present  cultural  state
and   in   their   present   environment.   A  thorough  ethnological  investi-
gation  of  other  Mrabri  groups  and  a  more complete survey of  genetic
traits   and   environmental   conditions   (more   complete  in  the  number
of   different  examinations   as   well   as   in   the  number  of   individuals
examined)  will    not   only   increase  our   knowledge   of   human  life  at
an   early  primitive  stage   but   may  also  provide   a   solution  to  some
problems  of  human  evolution.


(1)    As   it  was  established  that  the people  previously  known
 under   the   names   Khon   Pa   and  Phi  Tong  Luang  call
 themselves  Mrabri,  the  latter  name   will   be  used  exclu-
 sively  unless  reference  to  previous reports  is  made.

(2 )   Kraisri  Nimmanahaeminda  and J.  Hartland-Swann.
J.  Siam 
Soc. L. 165, 1962






176                                                  Gebhard Flatz


          (3)     Bernatzik, H.,  editor. Die grosse Voelkerkunde.
           Vol. II. Herkul, Frankfurt, 1954.

          (4)     The description  of  the  various  methods would take undue
           space  in   a  journal  not   primarily  directed   to  the  medical
           reader.  Information  concerning  methods  may  be  obtained
           from  the  author.

           (5)    Von   Eickstedt,   E.   Rassenkunde   und   Rassengeschichte
           der  Menschheit.  Fischer.  Stuttgart 1934.

           (6)    see (3), figure 95.

           (7)    Schwidetzky,  I.  Die   neue  Rassenkunde.    Fischer.  Stutt-
           gart,  1962.

           (8)    The  author   is   indebted   to   the   persons  listed  for   their
           support  by   aid   in  or  carrying  out  the  mentioned  exami-
           nations  at  their laboratories :

          Prof.   Dr. J. H.   Jonxis,  Director,  and  Dr.  C. Pik,  Chief   of
          Laboratory,   Department    of    Paediatrics,   University   of
          Groningen,   The    Netherlands    (  Hemoglobin  electropho-
          resis)  Dr.  Sommai  Sringam,  Chief  of   the   Blood  Bank  at
          Queen  Saovapha  Institute,  Bangkok   ( Blood group deter-
          mination )  Major   S. B.  Halstead.  Affiliation  and contribu-
          tion  described  in  the  text.

          Miss  Pradap  Ramabutr,  Chief  of  Laboratory,  McCormick
          Hospital,   Chiengmai.    ( Hemoglobin,   blood   smears,   and
          serologic  tests  for  syphilis ).

          (9)    Young,  G.   The   Hill   Tribes   of   Northern  Thailand.  The
          Siam  Society.   Bangkok, 1962.

         (10)   Special  thanks  are  due  to  the  Honorary  Treasurer of  the
         expedition  for  the  collection  of  this  delicate  material.

         (11)  Bernatzik,   H.   Die   Geister  der  gelben  Blaetter.     Bruck-
         mann.   Munchen, 1938.






( 12 ) For  a  discussion  of  these  problems,  see :

Dobzhansky,  T.  Genetics  and  the  origin  of  species.
  University  Press. New  York, 1941.
C., Die  Grundlagen  der  menschlichen  Erblehre.
Goettingen 1955.

(13)    These  views    are    not    in   complete  agreement  with   the
  derived  from   the  first  investigations of abnormal
  in  Thailand.  The  results,  of  French  workers
Cambodia  and  of  a  study  of  6000  individuals  in  Thai-
  by  the  author ( to  be  published ) are  in  favor of  this

I  wish   to   thank   the  leader  of  the Mrabri  expedition  of  the
   Society,   1963,   Mr. Kraisri   Nimmanahaeminda,  for   the   invita-
   to    participate    in  the   expedition;   and   Prof.  Dr. Hungerland,
  of    the  Dept.  of   Pediatrics,   University  of   Bonn,   for    his
  and for the  permission to extend  my  stay in Thailand.

Address : Universitaets-Kinderklinik, Koblenzer St. 119,
Bonn, Germany.



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