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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Página 16
... it could be shown that the greyhound , bloodhound , terrier , spaniel , and bull - dog , which we all know propagate their kind so truly , were the offspring of any single species , then such facts would. 16 CHAP . I. VARIATION.
... it could be shown that the greyhound , bloodhound , terrier , spaniel , and bull - dog , which we all know propagate their kind so truly , were the offspring of any single species , then such facts would. 16 CHAP . I. VARIATION.
Página 32
... plants , but merely go over their seed - beds , and pull up the " rogues , " as they call the plants that deviate from the proper standard . With animals this kind of selection is , in fact , also followed. 32 CHAP . I. SELECTION BY MAN .
... plants , but merely go over their seed - beds , and pull up the " rogues , " as they call the plants that deviate from the proper standard . With animals this kind of selection is , in fact , also followed. 32 CHAP . I. SELECTION BY MAN .
Página 33
... of the importance of the principle in works of high antiquity . In rude and barbarous periods of English history choice animals were often imported , and. C3 CHAP . I. 33 METHODICAL SELECTION . kind of selection is, in fact, also followed..
... of the importance of the principle in works of high antiquity . In rude and barbarous periods of English history choice animals were often imported , and. C3 CHAP . I. 33 METHODICAL SELECTION . kind of selection is, in fact, also followed..
Página 34
... kind of Selec- tion , which may be called Unconscious , and which results from every one trying to possess and breed from the best individual animals , is more important . Thus , a man who intends keeping pointers naturally tries to get ...
... kind of Selec- tion , which may be called Unconscious , and which results from every one trying to possess and breed from the best individual animals , is more important . Thus , a man who intends keeping pointers naturally tries to get ...
Página 35
... kind could never be recognised unless actual measure- ments or careful drawings of the breeds in question had been made long ago , which might serve for com- parison . In some cases , however , unchanged , or but little changed ...
... kind could never be recognised unless actual measure- ments or careful drawings of the breeds in question had been made long ago , which might serve for com- parison . In some cases , however , unchanged , or but little changed ...
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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