Evening star., 1949-02-28
Stars, Men and Atoms
Average U. S. Life Span
Gained 6 Years Since "a
Mortality Rate Cut at All Ases;
New Drugs Seen Factor
Bv TFOm0S r, Henrv

bV IfOm0S N. henry
During the past IS years, six years have
been added to the length Of the average
human life in the United States.
The average age at death has increased
from 58.2 years to 64.S.
Much of the gain has come from lover
ing the mortality rate among children, but
there has been an appreciable increase
among other age groups. according to
report just issued by the Public Health
Service
Women have benefited most. The aver.
age age at death is 36 years higher for
women than for men-66.9 years as COM
pared to 633.
In general, the Public Health Service re-
port points out the average age at death
has been increasing since 1888. the first
year for which data are available covering
the entire United States. The life span Of
women has increased 13 per cent as COM
pared to 10 per cent for men.
Rates Vary With Age, Race and Sex.
Mortality varies greatly with age, race and
sex. the report says. 1t Is comparatively high
among infants less than one year old and is
lowest among children between and and
10 and H. After these age groups, the rate
Increases steadily with age. In each age
group. however, the rate for females is ap-
preciably lower than the rate for males.
Except in the group above rs the rate is lower
for the white than for the non white popu-
lation.
The report makes no attempt to give
causes for the overall increase. The decline
in white death rates has been going on for
half century due to better hygienic meas
ures. prenatal care, etc. Introduction Of
the sulfa drugs in the middle 30s, followed
by penicillin and streptomycin in the war
years. has undoubtedly been a considerable
factor.
Great hardwood forests covered much Of
Greenland. Spitzbergen and northern
Alaska 50.000,0O0 years ago.
Then these lands had an abundant sum-
mer rainfall. generally humid climate. and
temperature which seldom fell below
freezing in winter.
This is the picture constructed by DR..
r. w. CLANCY of the Carnegie Institution
OF Washington from the testimony of a
living eye-WitneSs-a species of sequoia
closely related to the California redwoods
which was discovered two years ago in iso-
lated ravines of central China. 1t is almost
precisely the same type of tree as is repre-
sented by fossils collected in the lands
around the North Pole which now are ice
covered.
DR.. CLANCY was primarily interested in
the trees growing in close association with
the newly found sequoiaS. They constituted
a forest family very similar to that shown
by fossils for Greenland and Spitzoergen.
Many of these have survived in other places
but not with the same associations. 1t can
be assumed that the one place where they
have stuck together has climatic conditions
quite similar to those of their original home
Forest Migrated.
The picture to emerge is one Of q vast
migrating forest driven southwark over
thousands of miles in millions of years as
the northern climate changed, and grad
ually breaking up as different species found
suitable habitats. The Arctic forest was
fomishing in the So-called dawn age" of
the biologists, about 50,OO0O00 years ago,
when Towering plants. singing birds and
the ancestors of present day mammals were
first appearing in the world
There are two other surviving islands Of
this ancient forest from which the sequoias
have been eliminated, Dr. CLANCY says in
a report to the National Academy of
Sciences. One is the hardwood forest of
the Wabash Valley in Illinois and Indiana.
The other is on the island of Hondo in
Japan. In both these places the trees of
the great Arctic forest found homeland
environments where they could settle down
and live together.
AS for ancient conditions in the far north,
DR.. CLANCY says: "A wet summer climate
seems to have been the primary requisite
with total annual rainfall in excess of 40
inches. Moderate temperature seldom fall
ing below freezing is also indicated, although
a winter characterized by lower tempera-
lures is indicated by the prevailing decidu-
Gus deaf shedding) habit. Possibly, how
ever, it was the darkness of the Arctic night
rather than low winter temperature which
brought about the annual shedding Of
leaves"