Page - 375 - in The Origin of Species
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Text of the Page - 375 -
FORMS OF LIFE CHANGING 375
phenomena, it will appear certain that all these modifications
of species, their extinction, and the introduction of new ones,
cannot be owing to mere changes in marine currents or other
causes more or less local and temporary, but depend on gen-
eral laws which govern the whole animal kingdom." M.
Barrande has made forcible remarks to precisely the same
effect. It is, indeed, quite futile to look to changes of cur-
rents, climate, or other physical conditions, as the cause of
these great mutations in the forms of life throughout the
world, under the most different climates. We must, as Bar-
rande has remarked, look to some special law. We shall see
this more clearly when we treat of the present distribution
of organic beings, and find how slight is the relation between
the physical conditions of various countries and the nature
of their inhabitants.
This great fact of the parallel succession of the forms of
life throughout the world, is explicable on the theory of
natural selection. New species arc formed by having some
advantage over older forms
; and the forms, which are al-
ready dominant, or have some advantage over the other
forms in their own country, give birth to the greatest num-
ber of new varieties or incipient species. We have distinct
evidence on this head, in the plants which are dominant, that
is, which are commonest and most widely diffused, producing
the greatest number of new varieties. It is also natural that
the dominant, varying, and far-spreading species, which have
already invaded to a certain extent the territories of other
species, should be those which would have the best chance
of spreading still further, and of giving rise in new countries
to other new varieties and species The process of diffusion
would often be very slow, depending on climatal and geo-
graphical changes, on strange accidents, and on the gradual
acclimatisation of new species to the various climates
through which they might have to pass, but in the course
of time the dominant forms would generally succeed in
spreading and would ultimately prevail. The diffusion
would, it is probable, be slower with the terrestrial inhabi-
tants of the distinct continents than with the marine inhabi-
tants of the continuous sea. We might therefore expect to
find, as we do find, a less strict degree of parallelism in the
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book The Origin of Species"
The Origin of Species
- Title
- The Origin of Species
- Author
- Charles Darwin
- Publisher
- P. F. Collier & Son
- Location
- New York
- Date
- 1909
- Language
- English
- License
- PD
- Size
- 10.5 x 16.4 cm
- Pages
- 568
- Keywords
- Evolutionstheorie, Evolution, Theory of Evolution, Naturwissenschaft, Natural Sciences
- Categories
- International
- Naturwissenschaften Biologie
Table of contents
- EDITOR'S INTRODUCTION 5
- AN HISTORICAL SKETCH of the Progress of Opinion on the Origin of Species 9
- INTRODUCTION 21
- Variation under Domestication 25
- Variation under Nature 58
- Struggle for Existence 76
- Natural Selection; or the Survival of the Fittest 93
- Laws of Variation 145
- Difficulties of the Theory 178
- Miscellaneous Objections to the Theory of Natural Selection 219
- Instinct 262
- Hybridism 298
- On the Imperfection of the Geological Record 333
- On the Geological Succession of Organic Beinss 364
- Geographical Distribution 395
- Geographical Distribution - continued 427
- Mutual Affinities of Organic Beings: Morphology: Embryology: Rudimentary Organs 450
- Recapitulation and Conclusion 499
- GLOSSARY 531
- INDEX 541