Charles Darwin's Works: The origin of species by means of natural selection...with additions and corrections from 6th and last English edD. Appleton, 1896 |
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... Variability - Effects of Habit and the use or disuse of Parts - - Inheritance Correlated Variation - ― - Character of Domestic Varieties — Difficulty of distinguishing between Varieties and Species - Origin of domestic varieties from ...
... Variability - Effects of Habit and the use or disuse of Parts - - Inheritance Correlated Variation - ― - Character of Domestic Varieties — Difficulty of distinguishing between Varieties and Species - Origin of domestic varieties from ...
Стр. 4
... variability of species in a state of nature ; but I shall , unfortunately , be compelled to treat this subject far too briefly , as it can be treated properly only by giving long catalogues of facts . We shall , however , be enabled to ...
... variability of species in a state of nature ; but I shall , unfortunately , be compelled to treat this subject far too briefly , as it can be treated properly only by giving long catalogues of facts . We shall , however , be enabled to ...
Стр. 6
... de- scendants of that species . Furthermore , I am convinced that Natural Selection has been the most important , but not the exclusive , means of modification . CHAPTER I. VARIATION UNDER DOMESTICATION . Causes of Variability -
... de- scendants of that species . Furthermore , I am convinced that Natural Selection has been the most important , but not the exclusive , means of modification . CHAPTER I. VARIATION UNDER DOMESTICATION . Causes of Variability -
Стр. 7
... Variability . WHEN we compare the individuals of the same variety or sub - variety of our older cultivated plants and animals , one of the first points which strikes us is , that they generally differ more from each other than do the ...
... Variability . WHEN we compare the individuals of the same variety or sub - variety of our older cultivated plants and animals , one of the first points which strikes us is , that they generally differ more from each other than do the ...
Стр. 8
... variability may be partly connected with excess of food . It seems clear that organic beings must be exposed during several generations to new conditions to cause any great amount of variation ; and that , when the organisation has once ...
... variability may be partly connected with excess of food . It seems clear that organic beings must be exposed during several generations to new conditions to cause any great amount of variation ; and that , when the organisation has once ...
Часто встречающиеся слова и выражения
acquired adapted advantage allied analogous appear Asa Gray beak become bees believe birds breeds caudicle cause cells characters climate closely colour common correlated crossed cuckoo degree developed difficulty distinct species disuse domestic animals domestic races doubt effects eggs existence extinct extremely facts favourable females flowers forms Fritz Müller genera genus giraffe gradations greater number groups habits Hence hermaphrodites hive-bee important improved increase in number individual differences inhabitants inherited insects instance instincts intercrossing intermediate kind lamellæ large number larger genera larvæ less likewise males manner Melipona Mivart natural selection naturalists nearly nest occasionally offspring organisation organs origin Origin of Species parent perfect period pigeons pollen pollen-grains present preserved principle probably produced progenitor quadrupeds rank Red Grouse relation remarked resemble rock-pigeon seeds sexes sexual sexual selection slight stamens sterile structure struggle supposed swimbladder tend tendency tion transitional tree variability variations varieties vary widely wings young
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Стр. 77 - We behold the face of nature bright with gladness, we often see superabundance of food ; we do not see or we forget, that the birds which are idly singing round us mostly live on insects or seeds, and are thus constantly destroying life ; or we forget how largely these songsters, or their eggs, or their nestlings, are destroyed by birds and beasts of prey...
Стр. 109 - ... perform strange antics before the females, which, standing by as spectators, at last choose the most attractive partner. Those who have closely attended to birds in confinement well know that they often take individual preferences and dislikes; thus Sir R. Heron has described how a pied peacock was eminently attractive to all his hen birds.
Стр. 229 - 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.
Стр. 1 - These facts seemed to me to throw some light on the origin of species — that mystery of mysteries, as it has been called by one of our greatest philosophers.
Стр. 162 - ... of the former and present buds by ramifying branches may well represent the classification of all extinct and living species in groups subordinate to groups. Of the many twigs which flourished when the tree was a mere bush, only two or three, now grown into great branches, yet survive and bear the other branches ; so with the species which lived during long-past geological periods, very few have left living and modified descendants.
Стр. 203 - Our ignorance of the laws of variation is profound. Not in one case out of a hundred can we pretend to assign any reason why this or that part differs, more or less, from the same part in the parents.
Стр. 77 - I have called this principle, by which each slight variation, if useful, is preserved, by the term natural selection, in order to mark its relation to man's power of selection. But the expression often used by Mr. Herbert Spencer, of the Survival of the Fittest, is more accurate, and is sometimes equally convenient.
Стр. 163 - From the first growth of the tree, many a limb and branch has decayed and dropped off; and these lost branches of various sizes may represent those whole orders, families, and genera which have now no living representatives, and which are known to us only from having been found in a fossil state.
Стр. 244 - Why should not Nature take a sudden leap from structure to structure? On the theory of natural selection, we can clearly understand why she should not; for natural selection acts only by taking advantage of slight successive variations; she can never take a great and sudden leap, but must advance by short and sure, though slow steps.
Стр. 138 - The truth of the principle, that the greatest amount of life can be supported by great diversification of structure^ is seen under many natural circumstances. In an extremely small area, especially if freely open to immigration, and where the contest between individual and individual must be severe, we always find great diversity in its inhabitants. For instance, I found that a piece of turf, three feet by four in size, which had been...