On the Origin of Species by Means of Natural Selection: Or, The Preservation of Favoured Races in the Struggle for LifeEaston Press, 1976 - 470 páginas |
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Página 284
... whole geological period ; and likewise to reflect on the changes of level , on the extreme change of climate , and ... whole of this period . It is not , for instance , probable that sediment was deposited during the whole of the glacial ...
... whole geological period ; and likewise to reflect on the changes of level , on the extreme change of climate , and ... whole of this period . It is not , for instance , probable that sediment was deposited during the whole of the glacial ...
Página 303
... whole groups of species last for very unequal periods ; some groups , as we have seen , have endured from the earliest known dawn of life to the present day ; some have disappeared before the close of the paleozoic period . No fixed law ...
... whole groups of species last for very unequal periods ; some groups , as we have seen , have endured from the earliest known dawn of life to the present day ; some have disappeared before the close of the paleozoic period . No fixed law ...
Página 323
... whole chain could be perfectly restored , as a new and distinct species ; for it is not pretended that we have any sure criterion by which species and varieties can be discriminated . He who rejects this view of the imperfection of the ...
... whole chain could be perfectly restored , as a new and distinct species ; for it is not pretended that we have any sure criterion by which species and varieties can be discriminated . He who rejects this view of the imperfection of the ...
Contenido
VARIATION UNDER NATURE | 30 |
STRUGGLE FOR EXISTENCE | 45 |
NATURAL SELECTION | 59 |
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Términos y frases comunes
accumulated adapted admit affinities allied species America ancient appear beak become bees believe belonging birds breeds cause cells characters climate closely allied colour common progenitor continuous crossed crustaceans degree developed difficulty distinct species divergence doubt effects eggs embryo existing exterminated extinct extremely facts favourable fertilised fertility flowers formation forms fossil Fritz Müller genera genus geological geological period gradations greater number groups of species habits Hence hybrids hybrids produced important increase individuals inhabitants inherited insects instance instincts intercrossing intermediate kind lamellæ larvæ less living male mammals manner marsupials migration modified descendants natural selection naturalists nearly nest occasionally offspring organisation organs Origin of Species parent peculiar perfect pigeons pistil plants pollen present preserved principle probably produced quadrupeds ranked reciprocal crosses remarked resemblance rudimentary seeds slight South America stamens sterility structure struggle successive supposed swimbladder theory variability variations varieties vary whilst whole wings young