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 vii
... INSTINCT . Instincts comparable with habits , but different in their origin- Instincts graduated - Aphides and ants - Instincts variable- Domestic instincts , their origin - Natural instincts of the cuckoo , ostrich , and parasitic bees ...
... INSTINCT . Instincts comparable with habits , but different in their origin- Instincts graduated - Aphides and ants - Instincts variable- Domestic instincts , their origin - Natural instincts of the cuckoo , ostrich , and parasitic bees ...
Página 5
... Instinct , or the mental powers of animals ; thirdly , Hybridism , or the infertility of species and the fertility of varieties when intercrossed ; and fourthly , the imperfection of the Geological Record . In the next chapter I shall ...
... Instinct , or the mental powers of animals ; thirdly , Hybridism , or the infertility of species and the fertility of varieties when intercrossed ; and fourthly , the imperfection of the Geological Record . In the next chapter I shall ...
Página 8
... instincts ; but how many cultivated plants display the utmost vigour , and yet rarely or never seed ! In some few such cases it has been discovered that very trifling changes , such as a little more or less water at some particular ...
... instincts ; but how many cultivated plants display the utmost vigour , and yet rarely or never seed ! In some few such cases it has been discovered that very trifling changes , such as a little more or less water at some particular ...
Página 172
... instincts be acquired and modified through natural selection ? What shall we say to so marvellous an instinct as that which leads the bee to make cells , which has practically anticipated the discoveries of pro- found mathematicians ...
... instincts be acquired and modified through natural selection ? What shall we say to so marvellous an instinct as that which leads the bee to make cells , which has practically anticipated the discoveries of pro- found mathematicians ...
Página 202
... be difficult , but we ought to admire the savage instinctive hatred of the queen - bee , which urges her instantly to destroy the young queens her daughters as soon as born , or. 202 CHAP . VI . DIFFICULTIES ON THEORY .
... be difficult , but we ought to admire the savage instinctive hatred of the queen - bee , which urges her instantly to destroy the young queens her daughters as soon as born , or. 202 CHAP . VI . DIFFICULTIES ON THEORY .
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Términos y frases comunes
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