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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1 페이지
... facts in the distribution of the inhabitants of South America , and in the geological rela- tions of the present to the past inhabitants of that con- tinent . These facts seemed to me to throw some light on the origin of species - that ...
... facts in the distribution of the inhabitants of South America , and in the geological rela- tions of the present to the past inhabitants of that con- tinent . These facts seemed to me to throw some light on the origin of species - that ...
2 페이지
... facts in illustration , but which , I hope , in most cases will suffice . No one can feel more sensible than I do of the necessity of here- after publishing in detail all the facts , with references , on which my conclusions have been ...
... facts in illustration , but which , I hope , in most cases will suffice . No one can feel more sensible than I do of the necessity of here- after publishing in detail all the facts , with references , on which my conclusions have been ...
4 페이지
... facts . We shall , however , be enabled to discuss what circumstances are most favourable to variation . In the next chapter the Struggle for Existence amongst all organic beings throughout the world , which inevi- tably follows from ...
... facts . We shall , however , be enabled to discuss what circumstances are most favourable to variation . In the next chapter the Struggle for Existence amongst all organic beings throughout the world , which inevi- tably follows from ...
12 페이지
... facts collected by Heusinger , it ap- pears that white sheep and pigs are differently affected from coloured individuals by certain vegetable poisons . Hairless dogs have imperfect teeth : long - haired and coarse - haired animals are ...
... facts collected by Heusinger , it ap- pears that white sheep and pigs are differently affected from coloured individuals by certain vegetable poisons . Hairless dogs have imperfect teeth : long - haired and coarse - haired animals are ...
14 페이지
... facts make me believe that the rule has a wider extension , and that when there is no apparent reason why a peculiarity should appear at any particular age , yet that it does tend to appear in the offspring at the same period at which ...
... facts make me believe that the rule has a wider extension , and that when there is no apparent reason why a peculiarity should appear at any particular age , yet that it does tend to appear in the offspring at the same period at which ...
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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