Evening star., 1932-12-13
Carnegie Biologists Close to
Solution of Enigma of
Evolution.
DAVENPORT DESCRIBES
PROGRESS OF RESEARCH
Route Taken by Geneticists in
Attacking Mystifying Process
Is Outlined in Report.
BY THOMAS r. HENRY.

evolution-the origin of species-is
| being approached closely by Carnegie
Institution biologists.
This is announced in the annual re-
, port of Dr. c. B. Davenport, head OF
| the department Of genetics. Only by
penetrating deeply into the basic ele-
ments Of life itself have the Carnegie
| geneticists been able to frame partial
explanation of process that has re-
| mained uneyplicable since the days OF
Darwin.
! In the past, biologists have accepted
the natural origin of new species pretty
| largely on faith, and have twisted un-
| comfortably when fundamentalists QueS-
| toned them very closely about it. The
laws OF geneticS, developed from i'm
mense accumulation of data since
Darwin. allowed for an almost infinite
number Of combinations Of unit char
| acters'-such, for example. as eye color
| or leg length-and slight individual va
ration in these characters themselves.
But. when everything was said and
DONE what was constituted was only a
, reconciliation of what had been The
genes, carriers of the unit characters.
| were like marbles of all shapes and
colors in a bag. The problem was to
l
| tirely different shapes and colors from
any that were there or to unite two or
three marbles in one There had to be
an explanation for the appearance Of
| something entirely new in the world
not for a recombination of already ex-
/! isting things.
New Species Appeared.
Biologists knew it happened, for new
| species appeared, especially in lower
| forms Of life, under their eyes. But
| they didn't know how They labeled
| these events mutations and sought in
vain for an explanation. A few years
ago it was found that irradiation of
cells with X-rays would produce mu-
! tations which could be transmitted to
| offspring Still what happened was not
| known. and it developed that great
| many of the changes were fatal to the
| possessor or its immediate descendants.
The Carnegie biologists attacked the
problem with renewed investigations Of
| the datura, plant prone to mutations,
and especially adapted to genetical in
vestigations. 1t was by experiments
with this plant that the Dutch biolo-
gist De Vries discovered independently
and made known for the first time the
/
stone of modern biology. and which had
been worked out before, unknown to the
scientific world, by the Austrian priest
| Menoel.
BY irradiation. 1t is announced. ar
/ tificial pure breeding species of ds~a
| have been produced through certain
| specific alterations in the chromosome
| arrangement, the nature of which could
| be observed. The chromosomes are
/, bundles of genes, or unit carriers. but
| the effect of the gene in the structure
| of the organism depends somewhat on
its spacial relationship to other genes.
Though these laboratory species are
| artificial" the report states" they rem
| der it not improbable that their coun-
| terpart may some time be found in ma
! ture. The possibility that species may
have arisen in nature by the same proc
esses as have produced our artificial
species is supported by the analytical
study of cflromosome differences in da-
tura. both from the standpoint Of in
traspecific and interSpecific differences
Segmental Interchange.
It is matter, it is explained, OF seq
mental interchange. Some of the genes
of one choromosome become attached
to another chromosome. Very similar
interchanges have been found in mu-
tationS which took place naturally.
The laws of heredity are SO complex
that they must be studied with the SIM
plest possible organism of which there
are many generations within rela-
lively short period In such complex
organism as man, with decades between
generations. the study of the funda-
mental mechanisms becomes almost i'm
possibly difficult. But the laws found
close to the bottom of the ladder of life
apply throughout nature and the Car
negie workers have been able to throw
considerable light on human genetics.
Among the most debated questions IS
! that of the inheritance of mental char
acters. Some investigators have gone
so far as to say that in this field there
is no inheritance at all. but that every
thing depends on environment, both
before and after birth. Light can come
only from fundamental researches,
since there are so many factors to be
| considered The Carnegie work de-
scribed in this report dealt with the
specific factors of ability in spelling
| and arithmetic from generation to gen.
Grafton. Evidence of hereditary trans
mission of these abilities, without con-
sideration of general intelligence, was
found although it apparently obeyed
| very complicated laws. The report
states, with reservations, the law that
as special capacity of the "mid-par-
ent''-the average of the father and
| mother-increases in any special school
increases likewise in the same subject.
This work." says the report. may
be said to add to the cumulative evi-
! Ioyoo thot v,ocpto1 ronct tit11tiOv of
the human organism is subject to the
same general laws as the strictly ply
| sical constitution, and is determined in
similar degree by genetic factors. 1t is
to be expected that mentality shall be
subject to the biological laws of the
organism"
Racial Stock Studied.
Much Of the progress of civilization
| in America has been mechanical and
dependent on invention. The Carnegie
geneticists undertook an exhaustive
study of which race in the great Amer
ican melting pot had contributed the
most to this mechanical advance
i've genius. The racial stock Of more
than 1000 present-day inventors was
analyzed in eighth parts. That is, an
inventor might be seven-eighths Eng
lish and one-eighth Scotch. Then the
Scotch racial stock was given one
eighth cre6it for him.
The results were rather surprising,
showing the French and Swedish racial
| stocks far ahead of all others. The
former were almost three times as in
ventive as the Anglo-SaxonS, while the
Scandinavians were little behind Eng
lish racial stock ranked considerably
Nn.fn oh Dnv cHH
German, Norwegian, swiss, Irish
! Scotch racial stocks Below the Eng
lish, in descending order to practically