On the Origin of Species by Means of Natural Selection: Or, The Preservation of Favoured Races in the Struggle for LifeJ. Murray, 1860 - 502페이지 "In considering the Origin of Species, it is quite conceivable that a naturalist, reflecting on the mutual affinities of organic beings, on their embryological relations, their geographical distribution, geological succession, and other such facts, might come to the conclusion that each species had not been independently created, but had descended, like varieties, from other species. Nevertheless, such a conclusion, even if well founded, would be unsatisfactory, until it could be shown how the innumerable species inhabiting this world have been modified, so as to acquire that perfection of structure and coadaptation which most justly excites our admiration. Naturalists continually refer to external conditions, such as climate, food, & c, as the only possible cause of variation. In one very limited sense, as we shall hereafter see, this may be true; but it is preposterous to attribute to mere external conditions, the structure, for instance, of the woodpecker, with its feet, tail, beak, and tongue, so admirably adapted to catch insects under the bark of trees. In the case of the misseltoe, which draws its nourishment from certain trees, which has seeds that must be transported by certain birds, and which has flowers with separate sexes absolutely requiring the agency of certain insects to bring pollen from one flower to the other, it is equally preposterous to account for the structure of this parasite, with its relations to several distinct organic beings, by the effects of external conditions, or of habit, or of the volition of the plant itself"--Introduction. (PsycINFO Database Record (c) 2012 APA, all rights reserved) |
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vi 페이지
... generic : secondary sexual characters variable - Species of the same genus vary in an analogous manner Reversions to long - lost characters - Summary 131-170 - CHAPTER VI . DIFFICULTIES ON THEORY . Difficulties on the. vi CONTENTS .
... generic : secondary sexual characters variable - Species of the same genus vary in an analogous manner Reversions to long - lost characters - Summary 131-170 - CHAPTER VI . DIFFICULTIES ON THEORY . Difficulties on the. vi CONTENTS .
vii 페이지
... THEORY . Difficulties on the theory of descent with modification - Transitions- Absence or rarity of transitional varieties - Transitions in habits of life - Diversified habits in the same species - Species with habits widely different ...
... THEORY . Difficulties on the theory of descent with modification - Transitions- Absence or rarity of transitional varieties - Transitions in habits of life - Diversified habits in the same species - Species with habits widely different ...
ix 페이지
... theory of descent with modification - Classification of varieties - Descent always used in classification ... theory of Natural Selection -Recapitulation of the general and special circumstances in its favour Causes of the general belief ...
... theory of descent with modification - Classification of varieties - Descent always used in classification ... theory of Natural Selection -Recapitulation of the general and special circumstances in its favour Causes of the general belief ...
5 페이지
... theory will be given : namely , first , the difficulties of transi- tions , or in understanding how a simple being or a simple organ can be changed and perfected into a highly developed being or elaborately constructed organ ; secondly ...
... theory will be given : namely , first , the difficulties of transi- tions , or in understanding how a simple being or a simple organ can be changed and perfected into a highly developed being or elaborately constructed organ ; secondly ...
56 페이지
... theory ; inasmuch as geology plainly tells us that small genera have in the lapse of time often increased greatly in size ; and that large genera have often come to their maxima , declined , and disappeared . All that we want to show is ...
... theory ; inasmuch as geology plainly tells us that small genera have in the lapse of time often increased greatly in size ; and that large genera have often come to their maxima , declined , and disappeared . All that we want to show is ...
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adapted affinities allied species America analogous ancient animals become bees believe birds breeds cause cells chapter characters cirripedes climate closely allied colour continuous crossed crustaceans degree difficulty distinct species divergence domestic doubt embryo Europe existing exterminated extinct extremely facts favourable Fcap fertility flowers formations forms fossil Gärtner genera genus geological geological period Glacial period greater number groups of species habits Hence hermaphrodites History hybrids hybrids produced important individuals inhabitants inherited insects instance instincts intercrossing intermediate land larvæ less living male mammals manner migration modification modified descendants natural selection naturalists nearly nest offspring perfect pigeons plants pollen Portrait Post 8vo present principle probably produced progenitor racter ranked reciprocal crosses remarked resemble rudimentary organs Second Edition seeds sexual selection Silurian slight South America sterility structure struggle successive supposed theory Third Edition tion variability variations varieties vary Vols widely Woodcuts