New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1872-05-15
DARWINISM.
TIE C,rsrs OF ORGANIC EVOLUTION.

LATIONsHIP OF APES TO MEN-ClV,LlEA-
TON THE CHIEF TENDENCY OF MANS DE
yELOPMENT.
Prof. John Fiske gave yesterday, at tue
Cooper Union, the third and closing lecture VI w.
short as it is interesting. ,,.,s |
In speaking Of the org gin and progress OF mr.
Investigations, he noted with admiration JUG COZ 49,,
aad patience which enabled that eminent saN'' ~
for % years upon his theories without p upnosO
The error which is not 5ufrequenty COMMUNISM
of alludinC 10 Mr.. Darwin as "o w
cortr,hrted notbing 10 the ESTABLISHMENTS VI
the derivation theory the doctrine OF ha'ur"
tien the lecturer rectihed by careIui sa'eneh' VI ~
uer,ts He was the first TO marshal the arguments run
slassacation embry Ology morphclogy aud dlstpuoi'
and thus fairly 10 establish the proposition tha' tnero
Rs hoon a derivation Of higher forms from
lever inst as in astronomy the heocentrc theory
ss not regarded completely established until inc
forces which II pcstulsted explained as idehcai
with forces already known the development theory
could secure but partial acceptance so long as IL s'
remained doubtful whether there was any known OF
movable causes sufficient 10 have brought aoou' tue
phenomena which that theory assumed TO nave taken
place. - -- ,,r,p,r,oxe
Mr. Darwin in explaining the evolution OF higher
lower forms life appeals only TO agences whch
are sti visibly in action. whether species III S"'0 "
nature are changing not at the present uhe' 0""
not be determined by direct observation, any more
than the motion OF the hour-hand OF cOoA
ooud be detected by gazing at 1t Tor one
second But there innumerable cases In when spe-
ces are made change rapidly through the oehOerae
intervention OF Notifications in the SPECIFIC char-
aoteIs Of domestcated organisms are the only ones
which take place rapidly that can actually observe
them; and the agency which produces these moGlnoa
tons is selection taking advantage OF that slght Du'
universal variation in organisms Implied by 'he lac' %
no two individuals in any species are exactly ahe ny
selecting and pairing for many generations u'e nnes'
spccmels Of the different of domestic ahlilais'
man produces breeds refined, perfected, ana often
entirely unlike the original ones Vegetable organisms
are also perfected aud changed by artihcial selec
ton. MT. Darwin's great achievement mas peen 10
show that similar process of selection going on
throughout the organic world without the knowledge OF
Intervention Of man. tends not only to maintain putto
produce adaptive alterations in plants and animals
HOW THE INCREASE WAS KEPT WITHIN BOUNDS
The process is q simple one when once we nave the
clue TO it, All plants and animals tend to increase III
high eeometrcal ratio and the old problem of the nails
In the horses shoe teaches what astounding affair
is eeometrical rate of increase. plant yielding one
hundred seeds yearly would in twenty years. II
all the seeds were TO reach maturity, pro
duce ten duOdecillOns Of adult plantsl III Is
probable that the unchecked reproduction OF many
insects crustaceans and fishes, could not long 60 on
without requiring the assimilation Of greater quantity
Of matter than contained in the whole solar system
We may now begin family TO realize how prodigOus is
the slaughter which increasingly goes ON throughout the
organic world. Deadly battles have been necessarily
waged on every square mile OF the earths he-bear1ng
surface since life began. Ii Is only thus that the
enormous Of each species has been Kept within
bounds OF the many offspring produced by each plant
and animal in the of those highest the scale,
but few attain maturity and leave offspring behind them
In this struggle for existence, few favored ones IN eeh
generation survive aud propagate in their offspring the
oualtes by virtue which they have survived Thus
we see what by natural selection" The Or
ganisms which survive and propagate their KIND are
those which are best adapted the conditions which
hot may NJ
use of metaphor, personfy Nature mighty
breeder selecting from each generation those
individuals which eetest strongest most sagaoious,
Hons with Simplest muscles wolves with keenest scent
flowers with necaT-untl in the course OF ur-
told ages the nubercss varieties OF organic life have
been produced by the process Of which man now
takes advantage in order to produce variations to
fut his own caprices Between natural selection and
selection by man, there is, however one important
difference Selection by tends TO produce varieties
adapted TO satisfy necessities inclination and
II direct reference TO the maintenance OF the
speces But natural selection, working with the stern
est methods from the general slaughter only
those individuals which best take of themselves,
and thus maintains each species in adaptation to its
environment.
CIRCUMSTANCES ALTER CASES.
II the conditions Of the EARTH the atmosphere, and the
solar radiance were everywhere 20 remain forever
altered aud If each Of plants and animals
always 10 remain confined to limited area, all
variations on either side OF the weLadiusted
mean would be necessarily cut off by natural
selection and species would be immutable. But con-
slant changes have been going since planet
first became fit TO support organic fe part Of the
earth's surface now has been rest the in
sensy Of radiance and the density Of atmosphere
are ever altering every species OF plant and animal
is continually pressing upon the limits Of the area
within which it is confined. Such changes in the oondi
tons of life preclude possibility of organisms
ing constant and living. Of animals plants In
which individuals varied would later
Inevitably be exterminated leaving progeny. Observa-
ton shows that there is such The members OF
each species slightly varying but so long the
environment remains constant natural selection pre-
vents variations from accommodating either side OF
the which is most advantageous to the species.
When the environment changes, il certain variations
on one side Of the established mean tend To bring
the individuals which manifest them adapta
ton to the environment these individuals will sur
average character OF the species will be slightly
altered. The amount Of variation, thus preserved
become enormous But these changes directly caused
by natural selection greatly aided and emphasized
~ GnSI Of use and dnse and by correlation of growth
or internal equbrationtho effect produced upon any
Ing part. The disuse of any physical power or
member, and the changes in al parts
change part caused by natural selection, cannot
fail 10 modify the entire structure. temperament and
mode OF life Even such slight change as an increased
thickness OF the wooly coat OF mammals may, by alter
ing excretory power OF the skin affect the functions
crease diminish the size of the animal which in turn
will modify its speed its muscular development, Its
mental faculties, and its habits OF life.
SERIES DEMOFsTRABLE PROPOSITIONS.
1t il sometimes thOughtessy said that the Darwinan
theory upon purely gratuous suppositons. and
be verified even IT be true. The case is very
different When analysed the theory Of natural selec
ton will be found TO consist of eleven propositions,