On the Origin of Species by Means of Natural Selection: Or, The Preservation of Favored Races in the Struggle of LifeAppleton, 1864 - 440 стор. |
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Сторінка 14
... greater variability is simply due to our domestic produc- tions having been raised under conditions of life not so uniform as , and somewhat different from , those to which the parent - species have been exposed under nature . There is ...
... greater variability is simply due to our domestic produc- tions having been raised under conditions of life not so uniform as , and somewhat different from , those to which the parent - species have been exposed under nature . There is ...
Сторінка 19
... greater degree , to males alone . A much more important rule , which I think may be trusted , is that , at whatever period of life peculiarity first appears , it tends to appear in the offspring at a correspond- ing age , though ...
... greater degree , to males alone . A much more important rule , which I think may be trusted , is that , at whatever period of life peculiarity first appears , it tends to appear in the offspring at a correspond- ing age , though ...
Сторінка 20
... greater length of horn , though appearing late in life , is clearly due to the male element . Having alluded to the subject of reversion , I may here refer to a statement often made by naturalists — namely , that our domestic varieties ...
... greater length of horn , though appearing late in life , is clearly due to the male element . Having alluded to the subject of reversion , I may here refer to a statement often made by naturalists — namely , that our domestic varieties ...
Сторінка 30
... greater number of generations . In a breed which has been crossed only once with some distinct breed , the ten- dency to reversion to any character derived from such cross will naturally become less and less , as in each suc- ceeding ...
... greater number of generations . In a breed which has been crossed only once with some distinct breed , the ten- dency to reversion to any character derived from such cross will naturally become less and less , as in each suc- ceeding ...
Сторінка 50
... greater number rank it as an undoubted species peculiar to Great Britain . A wide distance between the homes of two doubtful forms leads many naturalists to rank both as distinct species ; but what distance , it has been well asked ...
... greater number rank it as an undoubted species peculiar to Great Britain . A wide distance between the homes of two doubtful forms leads many naturalists to rank both as distinct species ; but what distance , it has been well asked ...
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The Origin of Species by Means of Natural Selection: Or, The ..., Том 1 Charles Darwin Повний перегляд - 1889 |
The Origin of Species by Means of Natural Selection: Or, the ..., Том 1 Charles Darwin Повний перегляд - 1898 |
Загальні терміни та фрази
accumulated adapted affinities allied species America amount ancient animals appear become bees believe birds breeds cause cells characters cirripedes climate closely allied colour continuous crossed crustaceans degree difficulty distinct species disuse divergence domestic doubt embryo endemic Europe existing exterminated extinct extremely facts favourable fertility flowers formations forms fossil Gärtner genera genus geological geological period Glacial period gradations greater number groups of species habits Hence hermaphrodites hybrids hybrids produced important individuals inhabitants inherited insects instance instincts intercrossing intermediate land larvæ less living look male mammals manner migration modification modified descendants natural selection naturalists nearly nest offspring organic organisation perfect pigeons pistil plants pollen present probably produced progenitor ranked reciprocal crosses remarked resemble rudimentary seeds seems sexual selection Silurian slight South America sterility structure struggle successive suppose swimbladder tend theory tion trees variability variation varieties vary whole widely
Популярні уривки
Сторінка 424 - In the distant future I see open fields for far more important researches. Psychology will be based on a new foundation, that of the necessary acquirement of each mental power and capacity by gradation. Light will be thrown on the origin of man and his history.
Сторінка 63 - There is no exception to the rule that every organic being naturally increases at so high a rate, that, if not destroyed, the earth would soon be covered by the progeny of a single pair.
Сторінка 79 - I may be allowed to personify the natural preservation or survival of the fittest, cares nothing for appearances, except in so far as they are useful to any being. She can act on every internal organ, on every shade of constitutional difference, on the whole machinery of life. Man selects only for his own good: Nature only for that of the being which she tends.
Сторінка 70 - I counted thirtytwo little trees ; and one of them, with twenty-six rings of growth, had during many years tried to raise its head above the stems of the heath, and had failed. No wonder that, as soon as the land was enclosed, it became thickly clothed with vigorously growing young firs. Yet the heath was so extremely barren and so extensive that no one would ever have imagined that cattle would have so closely and effectually searched it for food. Here we see that cattle absolutely determine the...
Сторінка 169 - If it could be demonstrated that any complex organ existed, which could not possibly have been formed by numerous, successive, slight modifications, my theory would absolutely break down.
Сторінка 63 - Hence as more individuals are produced than can possibly survive, there must in every case be a struggle for existence, either one individual with another of the same species, or with the individuals of distinct species, or with the physical conditions of life.
Сторінка 167 - To suppose that the eye with all its inimitable contrivances for adjusting the focus to different distances, for admitting different amounts of light, and for the correction of spherical and chromatic aberration, could have been formed by natural selection, seems, I freely confess, absurd in the highest degree.
Сторінка 378 - Nothing can be more hopeless than to attempt to explain this similarity of pattern in members of the same class, by utility or by the doctrine of final causes. The hopelessness of the attempt has been expressly admitted by Owen in his most interesting work on the 'Nature of Limbs.
Сторінка 187 - Under changed conditions of life, it is at least possible that slight modifications of instinct might be profitable to a species; and if it can be shown that instincts do vary ever so little, then I can see no difficulty in natural selection preserving and continually accumulating variations of instinct to any extent that was profitable. It is thus, as I believe, that all the most complex and wonderful instincts have originated.
Сторінка 165 - I can see no difficulty in a race of bears being rendered, by natural selection, more and more aquatic in their structure and habits, with larger and larger mouths, till a creature was produced as monstrous as a whale.