Evening star. [volume] (Washington, D.C.) 1854-1972, 1932-03-19
LAW Of EVOLUTION
IS ENLARGED UPON
DR.. W. H. LongIey of Car
negie Institution Presents
New Theories.
BY THOMAS r. HENRY.

A new and far-reaching ampliication
of the law of evolution" was presented
before the Washington Academy of Sci
ences Thursday night by DR.. w. H.
Longley, biologist of the Carnegie In
stitutiop of Washington.
He presented evidence Of a funda-
mental mathematical law, or family
of laws, whose members are essentially
alike, which apply to physical systems
throughout nature. He further pre-
Sented data to show that family of
plants or animals, including the human
family, is a special sort of physical
system in which the same laws hold
with such notifications as may be re-
quired by the special circumstances.
For the first time last night evolu
ton was presented as a mathematical
equation. The development of a race
of plants or animals was shown to pro-
coed along essentially similar lines as
mass of gas in an inclosed space.
The significance of DR.. Longley's
work, it was pointed out, Is that it links
evolution to some of the basic phenom-
ena of the physical universe, gives a
mathematical form to description of
the evolutionary process and reveals
the behavior of life itself as only a
more complicated form of the behavior
of atoms and molecules.
Darwinian in Principle.
ION the average" DR.. Longley said,
species belonging to large genera oc-
cupy large areas sand those belonging
to small genera small ones. This is
fact of the utmost Importance. 1t
seems impossible to explain it except
by assuming that the many widespread
species in the large genera are descen-
dant of an able ancestral species which
has had much success in increasing the
number of species of its general sort
in the world. The few and weak species
of the small genera are similarly the
descendants of weak ancestors which
have had small success in the produc-
ton of new kinds. But this explana-
ton of the correlation between the size
of a genus and the average range OF its
species Is to affirm that evolution is
Darwinian in principle and that varia-
ton. inheritance and natural selection
unite in bringing it to pass. This
makes the fact of evolution essentially
as certain as that Of the rotation of
the earth on its axis, which we neither
feel nor see, but infer primarily from
the changing aspect of the night sky:
Some is years ago Dr.. J. Z. wins
of Cambridge, England, discovered that
in great natural groups Of animals and
plants there is always great prepon-
derance Of genera OF one species and
that the proportion of genera of diff
ferent sizes is much the same from
group to group. This suggests that the
process of differentiation of genera
and species, which is the process Of
evolution, proceeds according to law.
The law of evolution may be written
in as precise a form as the laws OF
physics or chemistry and this law Is
one of a group naturally associated
and including some Of the best known
laws of nature"
Combination Of Laws.
In fitting together the new claw" of
evolution, the gas laws and the popu-
lation growth laws, DR.. Longley point
ed out that the former was in effect
a combination of the other two. In
the process of evolution species serve
as units which are capable of varia-
ton and reproduction. In the gas
laws atoms serve as units and these,
under special conditions, are capable
of variation but not of reproduction.
| They vary according to the pressure
exerted by other atoms in the SyS-
tenn. In the population laws, which
are lust as applicable to the increase
in the population of the United States
as to the increase OF the population
of micro organisms in closed bottle,
individuals serve as units and these are
capable Of reproduction but not OF
variation.
But, DR.. Longley showed, when the
animal or plant group is taken as a
unit it not only is capable of reproduc-
ton but, through the operation of the
laws of genetics of variation. The
working of the evolutionary process Is
seen in the behavior of groups.
Species population such as would in
clude all the bats or all the cactus
plants of the world" DR.. Longley said,
constitute another sort of physical
system affiliated with the others men
toned under the terms OF the amph-
fed kinetic theory. The unit species
gives rise to new species, an act OF
both variation and reproduction. Species
are active and act upon other species
at random. AS result the laws of this
very complex sort of physical system
include a law of differentiation, a law
| like the law of increase OF simple popu-
| lations, and laws which are struc-,
turally Of the same form as the laws
of normal gases.
"Direct study of the numerical rela-
lions of animals and plants as they
are known to science today shows that
evolution is a fact. Variation, inherit
ance, natural selection and isolation are
the factors by joint action of which it
has been brought about. From the
statistical point of view its process is
an orderly one. 1t Is a process
of differentiation which runs al
ways according to one formula. Its law
is definite, capable Of mathematical
statement, and is affiliated with the
laws of growth of simple populations,
the law Of distribution Of energy in the
line spectrum of glowing gases, and
with the laws OF normal gases under
the terms of kinetic theory amplified
! by recognition Of the fact that 1t is
mot necessary to restrict its terms to
| systems whose active units, acting at
srandom, are incapable of reproduction