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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9 페이지
... hand , we see domesticated animals and plants , though often weak and sickly , yet breeding quite freely under confinement ; and when , on the other hand , we see individuals , though taken young from a state of nature , perfectly tamed ...
... hand , we see domesticated animals and plants , though often weak and sickly , yet breeding quite freely under confinement ; and when , on the other hand , we see individuals , though taken young from a state of nature , perfectly tamed ...
41 페이지
... hand , nurserymen , from raising large stocks of the same plants , are generally far more successful than amateurs in getting new and valuable varieties . The keeping of a large number of individuals of a species in any country requires ...
... hand , nurserymen , from raising large stocks of the same plants , are generally far more successful than amateurs in getting new and valuable varieties . The keeping of a large number of individuals of a species in any country requires ...
42 페이지
... hand , cats , from their nocturnal rambling habits , cannot be matched , and , although so much valued by women and children , we hardly ever see a distinct breed kept up ; such breeds as we do sometimes see are almost always imported ...
... hand , cats , from their nocturnal rambling habits , cannot be matched , and , although so much valued by women and children , we hardly ever see a distinct breed kept up ; such breeds as we do sometimes see are almost always imported ...
50 페이지
... hand , they are united by many intermediate links , and it is very doubtful whether these links are hybrids ; and there is , as it seems to me , an overwhelming amount of experimental evidence , show- ing that they descend from common ...
... hand , they are united by many intermediate links , and it is very doubtful whether these links are hybrids ; and there is , as it seems to me , an overwhelming amount of experimental evidence , show- ing that they descend from common ...
55 페이지
... hand , if we look at each species as a special act of creation , there is no apparent reason why more varieties should occur in a group having many species , than in one having few . To test the truth of this anticipation I have ...
... hand , if we look at each species as a special act of creation , there is no apparent reason why more varieties should occur in a group having many species , than in one having few . To test the truth of this anticipation I have ...
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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