On the Origin of Species by Means of Natural Selection: Or, The Preservation of Favoured Races in the Struggle for LifeD. Appleton, 1909 - 430 páginas |
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Página 57
... come into competition with each other , and more especially to the members of the same genus or class having nearly similar habits of life . With respect to commonness or the number of individuals of DOMINANT SPECIES VARY MOST 57.
... come into competition with each other , and more especially to the members of the same genus or class having nearly similar habits of life . With respect to commonness or the number of individuals of DOMINANT SPECIES VARY MOST 57.
Página 59
... nearly equal masses , the species of the larger genera on one side , and those of the smaller genera on the other side , and it has invariably proved to be the case that a larger proportion of the species on the side of the larger ...
... nearly equal masses , the species of the larger genera on one side , and those of the smaller genera on the other side , and it has invariably proved to be the case that a larger proportion of the species on the side of the larger ...
Página 66
... nearly so unproductive as this - and their seedlings next year produced two , and so on , then in twenty years there would be a million plants . The elephant is reckoned the slowest breeder of all known animals , and I have taken some ...
... nearly so unproductive as this - and their seedlings next year produced two , and so on , then in twenty years there would be a million plants . The elephant is reckoned the slowest breeder of all known animals , and I have taken some ...
Página 67
... nearly all the young have been enabled to breed . In such cases the geometrical ratio of increase , the result of which never fails to be surprising , simply explains the extraordinarily rapid increase and wide diffusion of naturalised ...
... nearly all the young have been enabled to breed . In such cases the geometrical ratio of increase , the result of which never fails to be surprising , simply explains the extraordinarily rapid increase and wide diffusion of naturalised ...
Página 76
... nearly the same place in the economy of nature ; but probably in no one case could we precisely say why one species has been victorious over another in the great battle of life , A corollary of the highest importance may be deduced from ...
... nearly the same place in the economy of nature ; but probably in no one case could we precisely say why one species has been victorious over another in the great battle of life , A corollary of the highest importance may be deduced from ...
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Términos y frases comunes
accumulated adapted affinities allied species America analogous ancient animals appear archipelago become bees believe birds breeds cause cells characters cirripedes climate closely allied colour continuous crossed crustaceans degree difficulty distinct species divergence domestic doubt embryo endemic existing exterminated extinct extremely facts favourable fertilised fertility flowers formations forms fossil Gärtner genera genus geological geological period Glacial period gradations greater number groups of species habits Hence hybrids hybrids produced important increase individuals inhabitants inherited insects instance instincts intercrossing intermediate larvæ laws less living males mammals manner migration modification modified descendants natural selection naturalists nearly nest occasionally offspring organic organisation origin of species perfect pigeons plants pollen present principle probably produced progenitor ranked reciprocal crosses remarked resemble rock-pigeon rudimentary seeds sexual sexual selection Silurian slight sometimes South America sterility structure struggle successive supposed swimbladder tend theory variability variations varieties vary whole widely