On the Origin of Species by Means of Natural Selection: Or, The Preservation of Favoured Races in the Struggle for LifeJ. Murray, 1860 - 502 páginas "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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... individuals - Complex relations of all animals and plants throughout nature - Struggle for life most severe between individuals and varieties of the same species ; often severe be- tween species of the same genus - The relation of ...
... individuals - Complex relations of all animals and plants throughout nature - Struggle for life most severe between individuals and varieties of the same species ; often severe be- tween species of the same genus - The relation of ...
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... individuals of each species are born than can possibly survive ; and as , conse- quently , there is a frequently recurring struggle for existence , it follows that any being , if it vary however slightly in any manner profitable to ...
... individuals of each species are born than can possibly survive ; and as , conse- quently , there is a frequently recurring struggle for existence , it follows that any being , if it vary however slightly in any manner profitable to ...
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... individuals of the same variety or sub - variety of our older cultivated plants and ani- mals , one of the first points which strikes us , is , that they generally differ more from each other than do the individuals of any one species ...
... individuals of the same variety or sub - variety of our older cultivated plants and ani- mals , one of the first points which strikes us , is , that they generally differ more from each other than do the individuals of any one species ...
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... individuals , though taken young from a state of nature , perfectly tamed , long - lived , and healthy ( of which I could give numerous instances ) , yet having their reproductive system so seriously affected by un- perceived causes as ...
... individuals , though taken young from a state of nature , perfectly tamed , long - lived , and healthy ( of which I could give numerous instances ) , yet having their reproductive system so seriously affected by un- perceived causes as ...
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... individuals exposed to certain conditions are affected in the same way , the change at first appears to be directly due to such conditions ; but in some cases it can be shown that quite opposite conditions produce similar changes of ...
... individuals exposed to certain conditions are affected in the same way , the change at first appears to be directly due to such conditions ; but in some cases it can be shown that quite opposite conditions produce similar changes of ...
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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