Seite - 428 - in The Origin of Species
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428 ORIGIN OF SPECIES
attenuatus inhabits Tasmania, New Zealand, the Falkland
Islands, and the mainland of South America. This is a won-
derful case, and probably indicates dispersal from an Ant-
arctic centre during a former warm period. This case, how-
ever, is rendered in some degree less surprising by the spe-
cies of this genus having the power of crossing by some
unknown means considerable spaces of open ocean: thus
there is one species common to New Zealand and to the
Auckland Islands, though separated by a distance of about
230 miles. On the same continent fresh-water fish often
range widely, and as if capriciously; for in two adjoining
river-systems some of the species may be the same, and some
wholly different.
It is probable that they are occasionally transported by
what may be called accidental means. Thus fishes still alive
are not very rarely dropped at distant points by whirlwinds;
and it is known that the ova retain their vitality for a con-
siderable time after removal from the water. Their dispersal
may, however, be mainly attributed to changes in the level
of the land within the recent period, causing rivers to flow
into each other. Instances, also, could be given of this
having occurred during floods, without any change of level.
The wide difference of the fish on the opposite sides of most
mountain-ranges, which are continuous, and which conse-
quently must from an early period have completely prevented
the inosculation of the river-system on the two sides, leads to
the same conclusion. Some fresh-water fish belong to very
ancient forms, and in such cases there will have been ample
time for great geographical changes, and consequently time
and means for much migration. Moreover Dr. Giinther has
recently been led by several considerations to infer that with
fishes the same forms have a long endurance. Salt-water
fish can with care be slowly accustomed to live in fresh
water; and, according to Valenciennes, there is hardly a
single group of which all the members are confined to fresh
water, so that a marine species belonging to a fresh-water
group might travel far along the shores of the sea, and
could, it is probable, become adapted without much difficulty
to the fresh waters of a distant land.
Some species of fresh-water shells have very wide ranges,
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Buch The Origin of Species"
The Origin of Species
- Titel
- The Origin of Species
- Autor
- Charles Darwin
- Verlag
- P. F. Collier & Son
- Ort
- New York
- Datum
- 1909
- Sprache
- englisch
- Lizenz
- PD
- Abmessungen
- 10.5 x 16.4 cm
- Seiten
- 568
- Schlagwörter
- Evolutionstheorie, Evolution, Theory of Evolution, Naturwissenschaft, Natural Sciences
- Kategorien
- International
- Naturwissenschaften Biologie
Inhaltsverzeichnis
- 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