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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 1 of 38)
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NIJ




UNIVERSITY OF CALIFORNIA
AT LOS ANGELES




DARWINISM TO-DAY

A DISCUSSION OF PRESENT-DAY SCIENTIFIC CRITICISM
OF THE DARWINIAN SELECTION THEORIES, TO-
GETHER WITH A BRIEF ACCOUNT OF THE
PRINCIPAL OTHER PROPOSED AUXIL-
IARY AND ALTERNATIVE THEO-
RIES OF SPECIES-FORMING



BY



VERNON L. KELLOGG

PROFESSOR IN LELAND STANFORD, JR., UNIVERSITY



/ 7 5 2.




NEW YORK

HENRY HOLT AND COMPANY
1907

6114 1



COPYRIGHT, 1907,

BY
HENRY HOLT AND COMPANY

Published August, 1007



THE QUINN ft BODEN CO. PRESS
RAHWAY, N. J.



M07



PREFACE.

THIS book is -written for the sake of presenting simply and
concisely to students of biology and to general readers the
present-day standing of Darwinism in biological science, and
to outline for them the various auxiliary and alternative
theories of species-forming which have been proposed to aid
or to replace the selection theories.

Our actual knowledge of the factors and mechanism of
organic evolution and our hypotheses and theories which
serve to fill in the present gaps in this knowledge have been
greatly added to and modified in the last few years. Much
that the general reader includes in his conception of organic
evolution, based on his reading of Darwin and Wallace and
Spencer, has been materially modified and some of it proved
untenable by modern investigation ; while much which had
no place in this earlier general understanding of evolutionary
method and process may now be confidently added to it. The
present time is one of unprecedented activity and fertility
both in the discovery of facts and in attempts io perceive
their significance in relation to the great problems of bio-
nomics. Both destructive criticism of old, and synthesis of
new hypotheses and theories, are being so energetically car-
ried forward that the scientific layman and educated reader,
if he stand but ever so little outside of the actual working
ranks of biology, is likely to lose his orientation as to the
trend of evolutionary advance. Precisely at the present mo-
ment is this modification of the general point of view and
attitude of philosophical biologists unusually important and
far-reaching in its relation to certain long-held general con-
ceptions of biology and evolution. This modification of the
general trend of evolutionary thought must also necessarily



iv PREFACE.

strongly affect our conceptions of the underlying principles
of such correlated sciences as sociology, pedagogy, etc. It
is, then, as a means of orientation in evolutionary matters for
the general reader and for the unspecialised but interested
student of science that this book is prepared.

That it may not be without some special usefulness to
more advanced students and biological workers there are
added, in appendices to the chapters, special notes (referred
to in the text by small super-numbers) in which are given
numerous exact references to general or special books or
papers, and accounts, in more or less detail, of particular
observations, experiments, or theoretical discussions, as well
as references to extended bibliographic lists of the subjects
under treatment. These notes will enable students, or others
interested, to look up the original sources of our knowledge
of the subjects of the various chapters, and to find more
detailed general or special discussions of them than can be
given in this book. These notes also enable the author to
introduce into the book some details of his own observations
and experiments touching various evolutionary subjects.

V. L. K.

STANFORD UNIVERSITY, June, 7907.



CONTENTS.

CHAPTER /.

PAGE

INTRODUCTORY: THE "DEATH-BED OF DAR-
WINISM" i

Modern activity in biologic study, i. Darwinism not
synonymous with evolution, 3. Present-day anti-Darwin-
ism, 4. Intemperate anti-Darwinism, 6. Outline of this
book, 7.

APPENDIX: Dennert's intemperate attack on Darwinism,
7. An anti-evolution university biologist, 8. Friedmann's
theory to replace evolution with divergence, 8.

CHAPTER II.

DARWINISM AND EVOLUTION DEFINED AND

DISTINGUISHED 10

Animal and plant kinds originate in one of three ways,
10. The theory of descent defined, u. The theory of
descent given validity by Darwin's explanation of the
cause of it, 12. Darwinism defined and analysed into its
fundamental assumptions and facts, 13,^ Sources of scien-
tific evidence for the theory of descent, 17. Relation of
theology, philosophy, pedagogy, and sociology to the
theory of descent, 20.

APPENDIX: Accounts of history of the descent theory,
22. Books giving the evidences for descent, 23. Dis-
cussions of the relation of descent and theology, 23.
Discussions of the relations of biology and philosophy, 24.
Biology and sociology, 24.

CHAPTER III.

DARWINISM ATTACKED 25

The attack of the theologians, 25. The present-day
attack of the scientific men, 25. Some of the principal
objections to natural selection summarised, 30. Darwinian
or fluctuating variations too small to serve as "handles"



VI CONTENTS.

PAGE

for natural selection, 36. Many specific differences are
indifferent, /. <?., not adaptive, 38. The extinguishing of
the extreme variations by interbreeding, 44. The im-
probability of the occurrence of the right variations at the
right time, 45. The difficulty of explaining the production
by natural selection of specialisations useful only in highly
complex condition, 49. The objection based on the over-
development of specialisations, 53. The objection based
on insufficient time, 54. The objection that natural selec-
tion tends to preserve the type rather than the variants,
and hence opposes change, 56.

APPENDIX: Books and papers on variation, 57. Cases of
marked variation in parthenogenetic animals, 58. Varia-
tion according to the law of probabilities, 59. Quetelet,
the discoverer of variation according to the laws of chance,
61. Example of trivial variations, 62. Nageli's seven
objections to species-forming by selection, 62. Wolff's
attack on the selectionists' assumption of the appearance
at the right time of the needed variation, 64. Example of
non-correlated variability in bilaterally repeated organs,
65. Henslow's antagonism to selection as an explainer of
floral correlations, 67. Wolff's objection to the necessary
assumption of identical and coincident variation in re-
peated structures, as feathers, scales, etc., 67. Example
of mal-adaption in the egg-laying habit of Phryganidia
caltformca, 68 Pieper's antagonism to the selection ex-
planation of colour and pattern in insects, 69.



CHAPTER IV.

DARWINISM ATTACKED (Continued') .... 70

Objection to the exclusively linear or quantitative char-
acter of the fluctuating or Darwinian variations, 70.
Gallon's law of regression, 71. Selection may produce
evolution (continuous change) but not species (discontinu-
ous series), 73. Pfeffer's objection based on the slowness
of species transformation, 75. The difficulty of explaining
the sterility of species by selection, 76. Selection cannot
explain extreme or complete degeneration of useless parts,
77. Objections to the assumed rigour of the struggle for
existence and to the actuality of intra-specific or personal
selection, 79. Indiscriminate extermination due to the
fortune of position and time, 80. The necessity of sexual



CONTENTS. vii

PAGE.

selection, a discredited theory, for the support of the
natural selection theory, 85. Natural selection rests on an
unwarranted assumption of its homology with artificial
selection, 86. Many biologists find natural selection
unable to account for known biologic conditions, 89. Sig-
nificance of the concessions of Darwinians, 90. Kor-
schinsky's extreme anti-Darwinian doctrine, 91. Delage's
"true role of selection," 93. Morgan's rejection of natural
selection as a species-forming factor, 93.

APPENDIX: Galton's statement of the law of regression,
97. Wolff's criticism of panmixia, 98. Example of inef-
fective panmixia, 100. Example of progressive degenera- /
tion inexplicable by natural selection, 100. Wolff's
discussion of the selection coefficient, 101. Example of
non-selection of trivial differences, 103. References to
books and papers on plant breeding, 105.



CHAPTER V.

DARWINISM ATTACKED (Continued): THE THEORY

OF SEXUAL SELECTION 106

Secondary sexual differences or characters, 107. Classi-
fication of secondary sexual characters, 107. Useless and
harmful characters not explicable by natural selection,
no. Theory of sexual selection to account for them: the
theory defined, in. Darwin's assumptions as basis of the
theory of sexual selection, 112. Difficulties in the way of a
general application of the theory, 113. The theory appli-
cable only to species in which males are more numerous
than females, 113. The passivity of females, 114. Males
of species in which no real pairing occurs also show strik-
ing secondary sexual characters, 114. Necessity of
assuming unproved aesthetic development among lower
animals, 114. Few recorded cases of observed choosing
by female, 115. Difficult to assume utility for many
secondary sexual characters, 115. Stolzmann's case of the
Andean humming-birds, 116. How explain the beginnings
of secondary sexual characters, 117. How explain orna-
mental characters appearing in both males and females,
118. Morgan's objections to sexual selection theory, 118.
Experimental evidence touching the theory is against it,
120. Mayer's experiments with Promethea and Porthetria
moths, 121. Douglass's and Diirigen's observations on



CONTENTS.

PAGE

defence of, and attack on, Darwinism, 187. The Weis-
mannian theories, 188. Panmixia, 190. The theory of
germinal selection, 193. The physical and chemical
structure of protoplasm, 194. Objections to the theory
of germinal selection, 200. Roux's theory of intra-selec-
tion, or the battle of the parts, 201. Objections to Roux's
theory, 203. The theory of organic selection, or ortho-
plasy, 208.

APPENDIX: List of Weismann's evolution papers, 212.
Theories of ultimate protoplasmic structure, 214. Encase-
ment theory, 215. Micromeric theories, 215. Buffon's
theory, 216. Spencer's theory, 217. Darwin's theory,
218. Nageli's theory, 219. De Vries's theory, 220. Hat-
schek's theory, 222. Delage's criticisms, 224. Le Dantec's
criticisms, 224. Verworn's biogen hypothesis, 225. De-
lage's machine theory, 225. Le Dantec's theory of
chemism, 225. Neo-vitalism, 226. Morgan's criticism of
Weismann's method of argument, 229. References to
discussions of orthoplasy, 229.



CHAPTER IX.

OTHER THEORIES OF SPECIES-FORMING (Continued}:

THEORIES AUXILIARY TO SELECTION (Continued) 232

Isolation theories, 232. Wagner's "Separations-theorie,"
234. Jordan's upholding of the importance in species-
forming of geographic isolation, 237. Biologic and sexual
isolation, or physiological selection, 243. Gulick's work
and conclusions, 249.

APPENDIX: References to discussions of isolation, 253.
Haacke's summary of Wagner's theory, 253. Grinnell's
studies of geographic differences in the chickadee, 255.
Further references to discussions of isolation, 261.



CHAPTER X.

OTHER THEORIES OF SPECIES-FORMING (Con-
tinued): THEORIES ALTERNATIVE TO SELEC-
TION 262;

Three general groups of theories proposed to replace the

selection theories as explanations of species-forming and

evolution, 262. The Lamarckian theory, 262. Objections

y to the Lamarckian factors, especially that of the inheritance



CONTENTS. xi

PAGE

of acquired characters, 266. Great use could be made of
the Lamarckian. factors in explaining evolution phenomena
if these factors could be given validity, 271. Orthogenesis
and determinate variation, pointing toward orthogenesis,
271. Nageli's theory of orthogenesis, 277. Eimer's ortho-
genetic theory, 282. Cope's theory of bathmism and
kinetogenesis, 285. Jaeckel's theory of metakinesis, 289.

APPENDIX: References to Lamarck's writings, 290. Brown-
Sequard's experiments on guinea pigs, 290. Hyatt's
studies of Planorbis, 295. Fischer's experiments with
butterflies, 296. Experiments with silkworms, 298. Ref-
erences to books and papers on inheritance of acquired j
characters, 305. Redfield's position, 305. Montgomery's ,
explanation of inheritance of variation, 306. Scientific f
aspects of Burbank's work, 310. Orthogenetic variation
in palaeontology, 319. A case of apparent determinate
variation, 319. Pfeffer's theory of orthogenesis, 320.
Eimer's theory of orthogenesis, 321. Apparent determi-
nate evolution, 322. Snodgrass's observances on bills of
Galapagos birds, 323. Cope's belief in orthogenetic evolu-
tion, 323. Whitman's belief in determinate variation, 325.
Cunningham and orthogenesis, 326.



CHAPTER XL

OTHER THEORIES OF SPECIES-FORMING (Con-
tinued); THEORIES ALTERNATIVE TO SELEC-
TION (Continued) 327

Heterogenesis or the mutations theory, 327. Formula-
tions of heterogenesis theories by von Kolliker, Dall,
Galton, and Emery, 330. Korschinsky's heterogenesis
theory, 333. De Vries's mutations theory, 337. Present
status of de Vries's theory, 348. Alternative theories to
explain secondary sexual characters, 352.

APPENDIX: Mendel and his work, 356. References to
recent work on Mendelism, 357. Darwin's examples of
race origin from sports, 357. A recent example of race
origin from a sport in cattle, 358. Gallon's discussion of
specific stability, 360. References to discussions by de
Vries of species-forming, 362. American opinions of the
mutations theory, 362. Davenport's example of species
origin by slight continuous change, 367. Merriam's criti-
cism of the mutations theory, 367. Plate's criticism of the



CONTENTS.

PAGE:



mutations theory, 368. References to theories explaining
secondary sexual characters, 373.



CHAPTER XII.

DARWINISM'S PRESENT STANDING .... 374

Natural selection the final control in evolution, but not
a sufficient explanation of species-forming, 374. Weak-
nesses of the substitutionary theories, 375. The unknown
factors of evolution, 377. Prime needs of evolution study;
first, the intensive study, statistical and experimental, of
variability, 378. Second, the means of cumulating varia-
bility along definite lines, 379. Third, the investigation of
adaptation, 380. A suggested argument for a belief in the
transference of ontogenic changes into phylogeny, 382. A
suggested automatic causal factor of variability, purposive
but not purposeful, 384. Our present ignorance and the
call to work, 387.

APPENDIX: Wigand's criticism of the selection theories,
387. Lankester's upholding of Darwinism, 389. De Vries's
discussion of species-forming by selection, 389. Delage's
estimate of selection, 390. Osborn's championship of the
unknown factors of evolution, 391. Klebs's conclusions
from experiments on plants, 392. Friedlander's discussion
of adaptation, 392. Loeb's attitude toward the problem of
species-forming, 393.

INDEX . 397






DARWINISM TO-DAY



DARWINISM TO-DAY.

rtos 2.

CHAPTER I.

INTRODUCTORY: THE "DEATH-BED OF
DARWINISM."

"VoM STERBELAGER DES DARWINISMUS !" This is the
title of a recent pamphlet l lying before me. But ever since
there has been Darwinism there have been occasional death-
beds of Darwinism on title pages of pamphlets, addresses,
and sermons. Much more worth consideration than any
clerical pamphlets or dissertations, under this title, by frisch-
gcbackenen German doctors of philosophy the title alone
proving prejudice or lack of judgment or of knowledge
are the numerous books and papers which, with less sensa-
tional headlines but infinitely more important contents, are
appearing now in such numbers and from such a variety of
reputable sources as to reveal the existence among biologists
and philosophers of a widespread belief in the marked
weakening, at least, if not serious indisposition, of Darwin-
ism. A few of these books and papers from scientific sources
even suggest that their writers see shadows of a death-bed.

The present extraordinary activity in biology is two-
phased ; there is going on a most careful re-examination or
Modem activ- scrutm y f the theories connected with organic
ity ia biologic evolution, resulting in much destructive criti-
cism of certain long-cherished and widely held
beliefs, and at the same time there are being developed and
almost feverishly driven forward certain fascinating and
fundamentally important new lines, employing new methods,



2 DARWINISM TO-DAY.

of biological investigation. Conspicuous among these new
kinds of work are the statistical or quantitative study of
variations and that most alluring work variously called
developmental mechanics, experimental morphology, ex-
perimental physiology of development, or, most suitably of
all because most comprehensively, experimental biology/
This work includes the controlled modification of conditions
attending development and behaviour, and the pedigreed
breeding of pure and hybrid generations. Now this combina-
tion of destructive critical activity and active constructive ex-
perimental investigation has plainly resulted, or is resulting,
in the distinct weakening or modifying of certain familiar
and long-entrenched theories concerning the causative factors
and the mechanism of organic evolution. Most conspicuous
among these theories now in the white light of scientific
scrutiny are those established by Darwin, and known, col-
lectively, to biologists, as Darwinism.

To too many general readers Darwinism is synonymous
with organic evolution or the theory of descent. The word

is not to be so used or considered. Darwinism,
wSfis!"* primarily, is a most ingenious, most plausible,

and, according to one's belief, most effective or
most inadequate, causo-mechanical explanation of adaptation
and species-transforming. It is that factor which, ever since
its proposal by Darwin in 1859, has been held by a majority
of biologists to be the chief working agent in the descent,
that is, the origin, of species. However worthy Darwin is of
having his name applied directly to the great theory of
descent for it was only by Darwin's aid that this theory,
conceived and more or less clearly announced by numerous
pre-Darwinian naturalists and philosophers, came to general
and nearly immediate acceptance the fact is that the name
Darwinism has been pretty consistently applied by biologists
only to those theories practically original with Darwin which
offer a mechanical explanation of the accepted fact of



INTRODUCTORY: "DEATH-BED OF DARWINISM." 3

descent. Of these Darwinian theories the primary and all-
important one is that of natural selection. Included with!-
this in Darwinism are the now nearly wholly discredited
theories of sexual selection and of the pangenesis of gem-
mules. It may also be fairly said that the theory of the
descent of man from the lower animals should be included in
Darwinism. For Darwin was practically the first naturalist
bold enough to admit the logical and obvious consequences
of the general acceptance of the theory of descent, and to
include man in the general chain of descending, or ascend-
ing, organisms. So that the popular notion that Darwinism
is in some way the right word to apply to the doctrine that
man has come from the monkeys is rather nearer right than
wrong. But biologists do not recognise the descent of man
as a special phase of Darwinism, but rather of the whole
theory of descent, or organic evolution.

Darwinism, then, is not synonymous with organic evolu-
tion, nor with the theory of descent (which two phases are
used by the biologist practically synonymously),
not synonymous Therefore when one reads of the "death-bed of
with evolution. Darwinism," it is not of the death-bed of or-
ganic evolution or of the theory of descent that one is read-
ing. While many reputable biologists to-day strongly doubt
the commonly reputed effectiveness^ of the Darwinian selec-
tion factors to .explain descent some, indeed, holding them
to be of absolutely no species-forming value practically
no naturalists * of position and recognised attainment doubt
the theory of descent. 4 Organic evolution, that is, the
descent of species, is looked on by biologists to be as proved
a part of their science as gravitation is in the science of
physics or chemical affinity in that of chemistry. Doubts
of Darwinism are not, then, doubts, of organic evolution.
Darwinism might indeed be on its death-bed without shaking
in any considerable degree the confidence of biologists and
natural philosophers in the theory of descent.



4 DARWINISM TO-DAY.

But the educated reader, the scientific layman, the thinker
and worker in any line of sociologic, philosophic, or even
theologic activity is bound to be disturbed and

Present-day '

anti-Darwin- unsettled by rumours from the camp of pro-
ism ' fessional biologists of any weakness or mortal

illness of Darwinism. We have only just got ourselves and
our conceptions of nature, of sociology and philosophy, well
oriented and adjusted with regard to Darwinism. And for
relentless hands now to come and clutch away our founda-
tions is simply intolerable. Zum Teufel with these German
f professors ! For it is precisely the German biologists who
are most active in this undermining of the Darwinian
theories. But there are others with them ; Holland, Russia,
Italy, France, and our own country all contribute their
quota of disturbing questions and declarations of protest
and revolt. The English seem mostly inclined to uphold
the glory of their illustrious countryman. But there are
rebels even there. Altogether it may be stated with full
regard to facts that a major part of the current published
output of general biological discussions, theoretical treatises,
addresses, and brochures dealing with the great evolutionary
problems, is distinctly anti-Darwinian in character. This
major part of the public discussion of the status of evolution
and its causes, its factors and mechanism, by working
biologists and thinking natural philosophers, reveals a
/ lack of belief in the effectiveness or capacity of the natural
selection theory to serve as a sufficient causo-mechanical
explanation of species-forming and evolution. Nor is this
preponderance of anti-Darwinian expression in current
biological literature to be wholly or even chiefly attributed
to a dignified silence on the part of the believers in selection.
Answers and defences have appeared and are appearing.
But in practically all these defences two characteristics are
to be noted, namely, a tendency to propose supporting
hypotheses or theories, and a tendency to make certain



INTRODUCTORY: "DEATH-BED OF DARWINISM."

distinct concessions to the beleaguering party. Thfc^fair '
truth is that the Darwinian selection theories, considered
with regard to their claimed capacity to be an independently
sufficient mechanical explanation of descent, stand to-day
seriously discredited in the biological world. On the other
hand, it is also fair truth to say that no replacing hypothesis
or theory of species-forming has been offered by the oppo-
nents of selection which has met with any general or even
considerable acceptance by naturalists. Mutations seem to
be too few and far between ; for orthogenesis we can dis- -
cover no satisfactory mechanism ; and the same is true for
the Lamarckian theories of modification by the cumulation,,
through inheritance, of acquired or ontogenic characters..
Kurs und gut, we are immensely unsettled.

Now but little of this philosophic turmoil and wordy
strife has found its way as yet into current American litera-
ture. Our bookshop windows offer no display, as in Ger-
many, of volumes and pamphlets on the newer evolutionary
study ; our serious-minded quarterlies, if we have any, and
our critical monthlies and weeklies contain no debates or
discussions over "das Sterbelager des Darwinismus." Our
popular magazines keep to the safe and pleasant task of
telling sweetly of the joys of making Nature's acquaintance
through field-glasses and the attuned ear. But just as cer-
tainly as the many material things "made in Germany" have
found their way to us so will come soon the echoes and
phrases of the present intellectual activity in evolutionary
affairs, an activity bound to continue as long as the new
lines of biological investigation continue their amazing out-
put of new facts to serve as the bases for new critical attacks
on the old notions and for the upbuilding of new hypotheses.
If now the first of these echoes to come across the water
to us prove to be, as wholly likely, those from the more vio-
lent and louder debaters, they may lead to an undue dismay



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 1 of 38)