Evening star., 1954-12-01
Humon Evolution Fust, !,
For Mon Is Adaptable
Our Species Con Adjust
To Almost Any Condition
By Thomos r. Henry

By Thomos R. Henry
Evolution, with the appearance OF
new characters. may be proceeding fast
est In the human species.
Man. above all other animals, has
the capacity to change" This thesis
is advanced by DR.. Carleton Coon. Uni
versity Of Pennsylvania anthropolog
in the annual report Of the Smithsonian
Institution.
The race. DR.. Coon says, has been
able to adjust. often with permanent
genetic changes. to almost any condi-
tionS found on this planet. Skin color
and stature. two Of the major factors
in adjusting to climate. can be altered
to some extent for large groups in one
or two generations.
Adjustment to cold" Dr.. Coon says,
requires large body mass. short ex-
tremities. much fat. deep vein routing
and a high basal metaboliSn, or. some
combination of these five features. Adj
justment to heat requires small body
mass, attenuated extremities, little fat.
extensive superficial vein routing, low
basal metabolism and greater number
OF sweat glands per unit of surface
area"
Three Types Of Skin Color.
One of the best known human racial
differences. DR.. Coon points out. is skin
color. There are three major types
persons with light skin who do not tan:
those with skin whose color varies with
the season, owing to the complex mech
anism OF tanning; and those with black
skin which never changes color. The
hrst type is confined largely to North
western Europe, generally cloudy re.
glon, where persons must remain fully
clothed at all times. The character ap-
parently has been fixed in the germ
plasm and may be of great disadvan-
tage to the owners when they migrate
elsewhere.
The second type is white, red, yellow
or brown skin whose color changes with
the seasons. sometimes becoming al
most black in summer when there ia
necessarily much exposure of large
areas to the sun, and white in winter
when this is a decided advantage. The
color changers" occupy all the tenn
perate areas of the world.
The third type is black. also appar.
emily fixed genetically, which largely is
confined within 10 degrees of the
Equator where there is little season
change and almost constant bright sun.
light. Even in the tropics it has no par
ticular advantage for dwellers in deep
forest. Many observations indicate. DR..
Coon says. that in Africa and Melanesia
the black forest dwellers are relatively
recent migrants out of grassland and
desert where the blacklist skins are
found and where they probably origi-
mated. African pygmies are not COM
pletely black. They may have been in
Africa only during the Christian era.
Black skin. DR.. Coon points out, never
developed in the tropical regions of the
Americas-the reason being that these
are thickly foreSted where protection
against strong sunlight is minor con-
Sideration.
Racial Adaptation.
Persons of small stature, DR.. Coon
says. have an advantage In hot climates
while large stature is advantageous in
the north. Here, he says, is one of the
clearest cases of racial adaptation.
I'm Europe" he says, "a regular de-
cline is found between the peoples of the
northwest. such as the Irish with an
average OF 157 pounds and the Firms
with 154, down to the Spaniards with
l32 and the racially white Berbers of
North Africa with 1874 In Asia the Nom
goloid peoples show the same tendency.
with the North Chinese weighing l42
and the Annamites 112 pounds, respec-
lively. The eastern Aleuts average $50
pounds, level maintained by most of
the Indians of the northern United
States and Canada, while the Maya of
Central America tip the scales at only
119 pounds"
Much the same evidence is found in
food habits as in adaptations to various
physical conditions. basal metabolism
and mechanisIns for loss and retention
OF body heat. All these adaptations have
been achieved by the race in somewhat
less than million years, and the ca.
pacity for them must be one Of the basic
and most important characters Of men.