Evening star. [volume] (Washington, D.C.) 1854-1972, 1931-05-01
EVOLUTION IDEA
HIT BY SCIENTIST
Dr.. BIackWood Questions
Speeding Changes by
Use of Rays.
BY THOMAS r. HENRY.

ID 1hOMAS ". HENhIs
The idea of evolution speeded by
notable and sudden hereditary changes
in bodily form, due to natural exposure
of the cells of plant or animal spe-
cies to gamma rays from radium, or
to the extremely penetrating cosmic
rays bombarding the earth from outer
space, was questioned on physical evil
dence by DR.. Oswald Blackwood of the
University of Pittsburgh. speaking be-
fore the American Physical Society at
the Bureau of Standards today.
Biologists long have been unable to
explain satisfactorily those evolutionary
changes-such as the greatly increased
size of the brain which separates man
from his nearest relative in the animal
kingdom-which seem ITO appear and
become fixed in short time. They
are known as mutations" They are
tied up in some way with the genes"
which are hypothetical bodies in the
cells carrying the various factors trans
mitted in heredity.
Produced in Fruit Fly. -
These hypothetical bodies are so ex-
tremely small that nobody has ever
seen them, and the evidence fer their
existence is that they fit SO we'll into
the known laws of heredity. Within
the past few years it has been shown
that mutations" can be produced arti-
ficially in the fruit f1y--the especial pet
of geneticists, because new generations
are produced SO rapidly-by exposing
them to X-rays of known intensity.
The effect of these X-rayS must be in
changing the composition CT the genes"
in some way, like bullets hitting a
target and knocking out some part OF
it, Now the gene, small as it is, is a
very large body compared to the atoms
CT which it IS composed, just as these
themselves are large compared to the
electrons and protons of which they are
composed.
Blackwood experimental with X-rays
to find out how large gene actually
was, estimating it as approximately six
ten millionths of millimeter in di-
ameter. Then he computed the num-
Der of ions-or atoms with some of their,
electrons knocked off through being
struck by the X-ray bullets-which
would be produced in body of that
size by bombardment with rays Of
known intensity. Ionization is assumed
to be accompanied by mutation.
Using the results from this expert
ment as basis, he computed that the
ioniZation which would be produced by
natural cosmic or gamma rays in a
given time would be only about one,
three billionth of that produced by the
X-rays.
Therefore, he concluded, the period
for a / per cent mutation due to bonn
bardment of cells by these rays in ma
ture would be about million years,
rather than a few weeks.
New Method of Measurement.
DR.. Arthur H. Compton of the Uni
versity of Chicago, Nobel prize winner
in physics, described a newly developed
nrRciG1lV fhnSp
almost inflnitesimal magnitudes, wave
lengths of light, by means of an X-ray
spectrometer. Measurement of X-ray
spectral lines was reported by DR..
F. K. Richtmyer of Johns Hopkins
University.
The temperature of the surface of the
Caribbean Sea may have close rela-
ton to rainfall in the Eastern United
States, DR.. Charles F.. Brooks of Clark
University reported to the American
Geophysical Union. For 10 years, he
said, records have been kept of the
temperature Of the Gulf Stream, which
flows into the Caribbean, and these
show that when the surface of that
sea is unusually warm, wet weather
generally follows few months later
along the Atlantic Coast.
A rich "Sea pasture" along the East
ern Coast of the United States was re-
ported by H. r. Siewell of the Buffalo
Museum of Science. He explained
that the coastal waters of North Amer
lea are fertile for the same reason that
land is fertile-content of nitrogen
and phosphorus. Plankton the tiny
one-celled plants of the sea, feed on
chemicals in the water just as plants
feed on chemicals in the soil Small
sea creatures eat the plankton, larger
sea animals feed on the small, and so
on, until the top of the scale is reached.
DR.. H. N Eaton of the Bureau of
Standards described plans for a ma
tional hydraulic laboratory where run
ming water will be studied behind glass
Models of sections of rivers can be built
to test flood control plans before put
ting them into effect. Bridges, dams,
lock gates and other structures can be
tried out in miniature before they actu-
ally are built.
Plans were discussed for establishing
the science of NEUROLOGY, dealing with
the cycle of water from its arrival as
rainfall to its evaporation or storage
in the ocean, in the United States were
discussed before the newly organized
NEUROLOGY sections of the Geophysical
Union. Studies are planned of the be-
havior of streams and ground waters,
rates of evaporation and storage of
water.
G. w. Littlehales of the photographic
Office of the Navy reported on the re-
cent inception of the International Sec
ton of NEUROLOGY at meeting in
Madrid. The American group will be-
come a member of this body.