Vernon L. (Vernon Lyman) Kellogg.

Darwinism to-day; a discussion of present-day scientific criticism of the Darwinian selection theories, together with a brief account of the principal other proposed auxilary and alternative theories of species-forming online

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Online LibraryVernon L. (Vernon Lyman) KelloggDarwinism to-day; a discussion of present-day scientific criticism of the Darwinian selection theories, together with a brief account of the principal other proposed auxilary and alternative theories of species-forming → online text (page 9 of 38)
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xSfBeieoti<m made the criticism tnat natural selection must
theory, which is be supported by the sexual selection theory
in order to stand. It makes no pretension of
explaining those extraordinary secondary sexual characters
such as ornamentation, songs, dances, odours, etc., which



not only are of no conceivable utility in the struggle for
existence but are in many cases of obvious disadvantage.
It relies wholly on sexual selection to explain them, and
yet in Wolff's eyes, and indeed in the eyes of most biologists,
sexual selection is practically discredited. It certainly can-
not explain some or many of these characters. (See account
of the sexual selection theory and the criticisms of it in
the next chapter.) Therefore, say Wolff and other anti-
Darwinians, natural selection is undermined in just so far
as it relies on the sexual selection theory to sustain it.

The other objection is that the natural selection theory
rests altogether too largely on an unwarranted analogy with
Natural selec- the phenomena of artificial selection. Plate "
XT T'Van ^ as ? ra P n ^ ca ^y expressed the contrast between
analogy with arti- the facts and processes of the two kinds of
final selection. se i ect j on m the following double-column table :


(1) rests on the wish (Willen)
and intelligence of the breeder,
except in a certain few cases of
"unintentional breeding" (See

Darwin, "Origin of Species.") .

(2) selects exceptional, most
widely divergent characters,
which appear only in a few

(3) complete isolation (pure
breeding) of the selected indi-

(4) often leads to exaggerated
development and to a sickly dis-
position, so that the whole con-
stitution suffers.

(5) leads comparatively rapidly
to new forms.

(6) The artificially-produced


(i) rests on the unvolitional
and . unreasoning resultant of
natural forces.

(2) is a selection of slight dif-
ferences, appearing simultane-
ously in many individuals.

(3) pure breeding is often very
difficult through the possibility
of crossing with the parental

(4) effects no injury to the
whole constitution, but on the
contrary a strengthening and
bettering of it.

(5) The modification of species
is effected, presumably almost
always, very slowly, for if it
were otherwise the appearance
of new species would be often

(6) The natural races (varie-


races are unstable; they revert ties) are stable; they do not

easily to the ancestral type if revert if the outer conditions

allowed to run wild; this is so (environment) remain constant;

probably because of their recent this is so probably because they

origin. are more firmly established by

reason of greater age.

(7) The artificially-produced (7) Natural varieties do not

races of the same species are cross in nature, either with

in most cases fertile among each other or with the ancestral

themselves. type.

The most important contrast between the two kinds of
selection lies, in my eyes at least, in the results obtained in
the character of the new forms. As Morgan 21 well says,
"we should not lose sight of the fact that even after the most
rigorous selective process has been brought to bear on
organisms, namely, by isolation under domestication, we do
not apparently find ourselves gradually approaching nearer
and nearer to the formation of new species, but we find, on
the contrary, that we have produced something quite differ-
ent. In the light of this truth, the relation between the two
selective theories may appear quite different from the inter-
pretation that Darwin gives of it. We may well doubt
whether nature does select so much better than does man,
and whether she has ever made new species in this way."

De Vries expresses very positively his belief that no artifi-
cial races are fixed and constant forms, in the sense that
natural varieties are. And this difference he believes to rest
on the radically different method " of origin of the two
kinds of forms; the domestic ones through carefully main-
tained selection; the natural ones through definitive imme-
diately fixed and enduring mutations.

If one stops to recall his own familiar knowledge of the
cultivated plants 2S and will roughly classify the cultivated
fruits and vegetables and ornamental plants with which he is
acquainted into two categories depending upon the mode of
reproduction, that is whether by division or by seeds, one
will be struck by the great preponderance of the first of the


two categories, the category, namely, of cultivated plant
races which are reproduced practically exclusively by
division (i. e., by cuttings, roots, scions, buds, etc.). The
reason for relying upon this kind of reproduction is, in
nearly every case, that these races do not breed true to seed,
i. e., the races are not fixed, are unstable. And even among
those races which we are accustomed to allow to reproduce
by seed how necessary it is to maintain the unusual environ-
ment, the exaggerated excellence of conditions of food
supply, humidity, protection from natural enemies, etc., if we
are to be successful in maintaining the parental characters of
the plant. Let a few individuals escape from the hothouse
or fertilised and sprinkled garden and see how soon, if they
can persist at all, they lose their characters of amelioration,
and become most pitifully unadorned.

In Pfeffer's 2< eyes the fundamental difference between
the two selection processes rests on the fact that the breeder
or plant ameliorator selects his individuals (the "to be
saved") on the basis of the character or condition of single
characteristics, while in nature survival is not determined
by such conditions, but on a basis of total or all-around fitness
or advantage. "The moment," says Pfeffer, "that one be-
lieves one's self to be able to place in parallel, simply and
directly and in general, the activity of the breeder and the
activity of the struggle for existence, and from this false
generalisation deductively to compare the selective work of
the breeder based on definitive special characters with the
automatic selective work of nature based on similar specific
characteristics, that moment one enters the camp of the
teleologists, whether he is doing it knowingly and will-
ingly, or not. In short it is a logical fallacy when one as-
sumes to substitute for the selective action of the breeder a
mechanically-working natural selection. Only in a single
kind of case has this position any justification, and this not
on account of logical correctness but on account of the pecu-


liar identity of the circumstances. And this is when a single
definitive characteristic is so all-important and dominant in
the life of a race or species that its presence really has a
life-and-death-determining value in the struggle for exist-
ence ; in this case the killing out of all the individuals not
provided with this specific character has the same re-
sult as an actual selection of the possessors of this char-
acter. The farther, however, the actual circumstances differ
from this case, in so far as a number of characteristics, and
not a single one, determines the outcome of survival, by just
so much less can the Darwinian explanation be made to
cover the situation."

De Vries sums up a full and careful discussion 25 of
natural as compared with artificial selection as follows : "In
conclusion, summing up all our arguments we may state that
there is a broad analogy between breeding-selection in the
widest sense of the word, including variety-testing, race-
improvement, and the trial of the breeding ability on one
side, and natural selection on the other. This analogy, how-
ever, points to the importance of the selection between ele-
mentary species, and the very subordinate role of intra-specific
selection in nature. It strongly supports our view of the
origin of species by mutation instead of continuous selec-
tion. Or to put it in the terms chosen lately by Mr. Arthur
Harris in a friendly criticism of my views : 'Natural selection
may explain the survival of the fittest, but it cannot explain,
the arrival of the fittest.' "

Finally I desire to add an objection that has real weight

with me, whatever may be the personal attitude of other

AniBcreasing naturalists or students to it. And that is, that

number of work- , . . . , .

ing biologists a constantly increasing number of working
unsatisfied with biologists find themselves, on a basis of their

the selection

theories. cumulative individual observation and experi-

ence and thought, unsatisfied with the explanation of adapta-
tion and species-forming offered by the selection theories.


Men using, or rather, testing, these theories every day in
their work in field and laboratory, find selection insufficient
to explain the conditions that their observation and experi-
ments reveal to them. These men are students in all the
different lines of biological work ; they are zoologists, bota-
nists, palaeontologists ; they are students of anatomy, physi-
ology, cecology, and taxomony (classification) ; they are
embryologists, pathologists, animal and plant breeders.
From all these lines of work come increasing complaints;
selection cannot explain for me what I see to exist. From
some the cry is more bitter : selection is a delusion and false
guide; I reject it utterly. For me, I repeat, this is an
objection of much significance and importance. Just as
modern chemistry seems to be finding its long useful atomic
theory now a restraint and a hindrance in understanding the
wonderful new facts that have followed the pushing out of
investigation into the rich fields of physical chemistry, so
the biological experimentalists, the students of variation and
heredity, of life mechanics, of physico-chemical biology,
are finding the rigid theory of selection's control of all
processes and phenomena a rack on which they will no
longer be bound.

Coupled with the significance of this general objection to
the reign of the selection theory a general objection that

the selectionists will say is simply the objection
The concessions , ' f '

of the selection- that the selection theory is objected to is the

ist8i added significance of the concessions in the way

of supporting theories that the neo-Darwinians have made
to the general increase and sharpness of scientific criticism
of selection ; conspicuous examples are Roux's theory of the
battle of the parts, and Weismann's theory of germinal
selection. This latter is no less than a neo-Darwinian ex-
planation of how determinate variation, that is ortho-
genesis, may be explained non-teleologically. Which is
practically to rob natural selection of all influence in the


primary determination of lines of descent. But to these

supporting and concessionary theories we shall come in

a later chapter.

To show how definitive and positive an anti-Darwinian

position is taken by some biologists I shall quote some para-
s Mnsk 's R ra P^ s f rom an interesting short paper by Kor-

radical anti-se- schinsky, 28 a Russian botanist whose formula-
ion position. t - on of the theory of species-forming by hetero-

genesis preceded that of de Vries by two years. In this
paper (which is a vorlaufige Mitteilung published in Ger-
man preliminary to the issuance, in the publications of the
Royal Academy of Sciences of St. Petersburg, of a larger,
more detailed paper) Korschinsky arranges in parallel
columns the various corresponding or contrasting items of
the selection theory compared with the heterogenesis theory
of the author himself (for this full table see chapter xi).
From this table I quote only the following statements to
show how differently from the Darwinian view the probable
effects of the struggle for existence may appear to another
naturalist and to what radically anti-Darwinian conclusions
a man may come who interprets the effects of selection in
this way:

"The origin of new forms can only occur under condi-
tions favourable for them, and the more favourable such
conditions are, that is, the less severe the struggle for ex-
istence is, the more energetic is their development. Under
severe external conditions new forms do not arise, or if they
appear they are extinguished.

"The struggle for existence, and the selection which goes
hand in hand with it, compose a factor which restricts new-
appearing forms and restrains wider variations, and which is
in no way favourable to the production of new forms. It
is indeed an inimical factor in evolution.

"Were there no struggle for existence, then there would
be no extinguishing of arising or already arisen forms. The


organic world could then develop into a mighty tree, whose
branches could all remain in blooming condition, so that
the now isolated extremest species would be united with all
others through gradatory forms.

"The adaptation resulting from the effects of the struggle
for existence is absolutely not identical with advance, for
higher-standing, more complex forms are by no means
always better adapted to outer conditions than the lower
ones. The evolution [used here by the author as synony-
mous with advance or progressive complexity] of organisms
cannot be explained in a purely mechanical way. In order
to explain the origin of higher forms from lower it is neces-
sary to postulate in the organisms a special tendency to ad-
vance which is nearly related to or identical with the
tendency to vary, which tendency compels the organisms
to advance so far as the outer conditions permit."

These declarations sound strange and perhaps almost
absurd in the ears of one accustomed for years to
hear only the Darwinian interpretation of the effects of the
struggle for existence and natural selection. But taken
up one by one, as they are by Korschinsky, and developed
and explained, they begin to have a kind of plausibility,
an appeal to our reason, of much that sort which the Dar-
winian interpretation has and makes. After all the Darwin-
ian interpretation is proved only in so far as it possesses a
high degree of plausibility and makes a convincing appeal
to our reason. Of exact proof, in the nature of observed
fact or result of experiment, or of mathematical demonstra-
tion, there is little in the case either of the Darwinian or
the Korschinskian interpretation.

Those other biologists 2T who, like Korschinsky, take the
extreme and positive stand that the struggle and selection
are not factors in evolution, or if factors are really hinder-
ing and opposing ones, constitute, however, by far the
smaller body in the ranks of the anti-Darwinian critics when


compared with those whose arraignment of selection is
chiefly a protest against its assumption of altogether an
undue share of influence in species-forming, and whose
principal attempt is to reduce selection to a secondary place
among evolutionary factors, giving first place to that influ-
ence or those influences which determine the character and
direction of variation. Still the totally anti-Darwinian
critics are not few, and are not without ingenuity and
capacity in debate.

But better justified by what we know to-day and far saner
in their estimate of the Darwinian factors are such critics
as Delage and Morgan. "The conclusion of
matfof selection. ^ s criticism," says Delage, 28 at the end of a
detailed critical discussion of the "true role of
selection," "is that selection is powerless to form species.
Its role, however, is not mil, but it is limited to the sup-
pression of variations radically bad, and to the maintaining
of the species in its normal character. Far from being an
instrument for the evolution of species it guarantees their
fixity." And elsewhere he says : "Species come from fixed
variations. The formation of species is due ordinarily to
general variation [a conception of change much like that of
de Vries's mutations and sudden fixed origin of elementary
species], very rarely to strong individual variation [sports or
discontinuous variations], and never to weak individual
variation [fluctuating or Darwinian variation].

Morgan " in a recent popular essay in which he takes a
strong stand against natural selection as a species-forming
Mor an'sad- ^ ac ^ OT an d in favour of "definite variations"
verse criticism of (de Vriesian mutations) concludes as follows:
ing vain of s "^ n ^ ne preceding pages I have tried to bring
lection. into contrast the point of view of the

Darwinian school and the newer conception of the sur-
vival of elementary species. I have tried to show what
.selection has meant to the selectionists. They have


never hesitated to take each particular character of an
animal or plant, and dress it up in more perfect gar-
ments, while the body of the species, if I may so speak,
has been left as it was before. There has been a con-
tinual tampering with the characters of the organism with
the laudable intention of doing with them that which na-
ture herself seems unable to do, namely, to dissociate them
from the rest of the organisation and perfect them in this
way or in that. It is this meddling with the fluctuating
characters of the species that has been the characteristic
procedure of the Darwinians, in their attempt to show how
new species have been created. In contrast to this method,
the theory of the survival of species assumes that a form
once made does not have its individual parts later disso-
ciated and adjusted to better fit the external needs of the
species. Such a new form can change only by becoming
again a new species with a new combination of characters ;
some of which may be more developed in one direction than
before, others less, etc.

"New forms on the Darwinian theory are supposed to be
created by a process of picking out of individual differences.
If, in addition to this, Darwin supposed that at times varie-
ties and species crowd each other out nothing new is thereby
created.* On the other hand the theory of the survival of
definite variations refers the creation of new forms to an-

*"If the survival of certain species determines, in a metaphorical
sense, the kinds of future mutations that occur, the course of evo-
lution may appear to be guided by selection or survival ; but, how-
ever true it may be that selection acts by lopping off certain
branches, and limits to this extent the kinds of possible future muta-
tions, the origin of the new forms remains still a different question
from the question of the survival of certain species. This negative
action of selection is not the process that most Darwinians have
had in mind as the source of the origin of new species. It is true
that Weismann believes that selection of individual differences deter-
mines the origin of new species, and that the creation of these new
species determines the future course of variations in the same direc-
tion, but his argument that fluctuating variations can go on indefi-


other process, namely, to a sudden change in the character
of the germ. The creating has already taken place before
the question of the survival of the new form comes up.
After the new form has appeared the question of its per-
sistence will depend on whether it can get a foothold. The
result is now the same as when species crowd each other
out. This distinction appears to me to be not a matter of
secondary interest, but one of fundamental importance, for
it involves the whole question of the 'origin of species.' So
far as a phrase may sum up the difference, it appears that
new species are born; they are not made by Darwinian
methods, and the theory of natural selection has nothing to
do with the origin of species, but with the survival of already
formed species. Not selection of the fittest individuals, but
the survival of the sufficiently fit species.

'There is a fundamental difference between the idea that
fluctuating variations become specific characters through
accumulation by selection, and the idea that new species
arise as definite variations, which, with their appearance,
characterise the new form as a new species. According
to the Darwinian theory, natural selection performs a double
duty, first, to build up new species, and second, to maintain
them in competition with other species. According to the
other view, species are not formed by any kind of selection,
and the question of survival only concerns the maintenance
of species already formed. The primary problem is the
problem of the 'origin of species.' The central idea is not

nilely varying in the direction of selection is refuted by what has
been actually found to be the case when the process of selection of
fluctuating variations is carried out. Most of the individuals of a
species may be brought in this way to show the particular character
selected in its highest degree as a fluctuating variation, but it appears
not possible to transgress this limit ; and rigorous selection in every
generation is necessary to hold the individuals to the highest point
reached. Only by the appearance of new definite variations can a
given character be permanently fixed, or a new species created that
will show fluctuating variations around the new standard.


what species survive, but how species originate ; no matter
whether they are going to become victorious or not.

"After a species has appeared it will surely be admitted by
every one, that forms that can survive will survive! If
Darwin's theory meant only this to those who adopted it,
is it not surprising that such a truism should have been
hailed as a great discovery? Was not the theory heralded
because it seemed to explain how new species arose ? What
shall we say then when we find a situation like that existing
at the present time, when we are told that after all the only
difference between Darwin's theory of natural selection and
the theory of the survival of definite variations is that in the
one case fluctuating variations are selected, and in the other
mutations, and that in both cases natural selection is the
key to the evolutionary process ! Is not the 'origin of
species' still the real point at issue?

"I yield to no one in admiration for what Darwin has done
in behalf of the biological sciences, for he succeeded, where
the great French zoologists failed, in establishing the prin-
ciple of evolution. Furthermore no other hypothesis, that
has as yet been proposed, accounts so well for the wide-
spread occurrence of adaptation of organisms to the environ-
ment as does the principle of natural selection. But appre-
ciation of Darwin's claims in these directions need not blind
us to the insufficiency of the theory of natural selection to
account for the origin of species; nor to the fact that his
followers have been especially concerned in propounding
and making application of this side of the theory. They
have shown little interest in selection as the great conserv-
ing factor of evolution, and the reason for this is not far
to seek, because of the much greater importance that they
have attributed to natural selection as a creative factor in
building up individual differences into specific characters."



1 De Vries, H., "Die Mutationstheorie," Vol. I, pp. 83 ff., 1901.

2 Wolff, Gustav, "Der gegenwartige Stand des Darwinismus," p.
Q, 1896.

* Weismann, A., "Aufsatze iiber Vererbung," p. 116, 1892.

* Gallon, Francis, "Natural Inheritance." I quote from Galton as
follows :

"As soon as the character of the problem of filial descent had
become well understood, it was seen that a general equation of

Galton'a state- the same form as that by which it was expressed,
mentofthelaw also expressed the connection between kinsmen in
of regression. every degree. The unexpected law of universal re-
gression became a theoretical necessity, and on appealing to facts,
its existence was found to be conspicuous. If the word "peculiarity"
be used to signify the difference between the amount of any faculty
possessed by a man and the average of that possessed by the popu-
lation at large, then the law of regression may be described as
follows: Every peculiarity in a man is shared by his kinsmen, but
on the average in a less degree. It is reduced to a definite fraction
of its amount quite independently of what its amount might be.

Online LibraryVernon L. (Vernon Lyman) KelloggDarwinism to-day; a discussion of present-day scientific criticism of the Darwinian selection theories, together with a brief account of the principal other proposed auxilary and alternative theories of species-forming → online text (page 9 of 38)