Evening star., 1935-03-26
STARS. MEN AND ATOMS
Notebook of Science Progress in Field,
Laboratory and Study.
nv THOMLS HENRY
BY THOMAS r. HENRY.

because mankind is not looking for
sterile Standardization of particular
qualities. Moreover. when the test Is
applied in the field of general ability
DR.. Pearls own researches give quite
a different picture from that which
often has been presented to the public
and upon which alarming predictions
of race deterioration have been based.
First. he points out, the great ma
jority of outstanding individuals come
from mediocre parents.
Second, so-called geniuses tend to
be very unfortunate in their offspring.
BY this test of progeny" the fact
that a man himself has succeeded in
rising above the dead level Of his fel-
lows is no indication that his sons
will have the same capacity to do SO
under the same circumstances. Even
If much more were known about the
laws of human heredity, 1t would be
impossible to differentiate the roles Of
lucky breaks" and favorable environ
ment from superior innate qualities,
possibly transmittable, in any sue
cessful individual.
LII. Z Cdll PAOeCcNCo otdAAlcO WIZ
dogma of human heredity, which has
contaminated so much biologico-
philosophical thinking and has acted,
like all dogmas, to slow the progress
of science. Present-day biological
concepts, he pointed out. would justify
restriction of reproduction only with
respect to the obvious biological de-
fectives.
Dr. Pearl described for the first time
another experiment in his laboratory
at Johns Hopkins which proves con-
clusively the stability Of q simple
hereditary trait.
It was an experiment with fruit flies,
the favorite material of the geneticist.
Normally these flies have functioning
wings But many are born with yes
tigical wings, which are greatly under
sized and cannot be used for flying.
Whether an individual has functional
or vestigal wings depends upon q
single gene.
DR.. Pearl has mated the winged and
wingless flies over q period Of Is years
and 800 generations. This is the long
est controlled experiment in genetics
ever made. First winged and wingless
flies were mated. Since the winged
form Is dominant, all the offspring
had wings, but in the third genera
ton, following the Mendelian law, the
recessive trait appeared again and half
the flies were Of the vestigial winged
type.
rrh.,. 1ottar x.,a~~ al I;1Iad opd fhe
winged onces mated with vestigials OF
another brood. The same process was
repeated through the three genera
tions. Now, at the end of 800 gener-
ations, the hereditary process Is work.
ing exactly as 1t did in the beginning.
If the same experiment were to be
performed with human beings it would
require approximately 5000 years. 1t
is a striking proof, DR.. Pearl pointed
out, Of the stability of the gene and
the resistance Of the species. once
established, to morphological change.
This explains, he pointed out, why
some organisms have survived with
absolutely no morphological change
which can be detected by experts for
hundreds of millions of years-almost,
in fact, since the first known evi-
dences Of life on earth.
Probably the fundamental motiva-
ton OF life, DR.. Pearl said, is the
urge for individual survival.
Even the urge for reproduction and
survival Of the species, he pointed
out, may well be considered a re-
sultant Of this, especially in man, for
the self Is identified with the offspring
and the parents see in them their
own immortality. The individual
makes everything subservient to the
desire for survival.
But. the biologist pointed out, there
are various social phenomena in na-
tlxe which would seeun to cont1Adict-