The Origin of Species by Means of Natural Selection,: Or the Preservation of Favoured Races in the Struggle for LifeJohn Murray, Albemarle Street., 1891 - 432 páginas |
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Página 62
... stages of the varieties of the silkworm ; in the eggs of poultry , and in the colour of the down of their chickens ; in the horns of our sheep and cattle when nearly adult ; -so in a state of nature natural selection will be enabled to ...
... stages of the varieties of the silkworm ; in the eggs of poultry , and in the colour of the down of their chickens ; in the horns of our sheep and cattle when nearly adult ; -so in a state of nature natural selection will be enabled to ...
Página 84
... stage of development . The Probable Effects of the Action of Natural Selection through Divergence of Character and Extinction , on the Descendants of a Common Ancestor . After the foregoing discussion , which has been much com- pressed ...
... stage of development . The Probable Effects of the Action of Natural Selection through Divergence of Character and Extinction , on the Descendants of a Common Ancestor . After the foregoing discussion , which has been much com- pressed ...
Página 87
... stage of descent their pre- decessors and their original progenitor . For it should be remem- bered that the competition will generally be most severe between those forms which are most nearly related to each other in habits ...
... stage of descent their pre- decessors and their original progenitor . For it should be remem- bered that the competition will generally be most severe between those forms which are most nearly related to each other in habits ...
Página 88
... stage of descent , so as to have become adapted to many related places in the natural economy of their country . It seems , therefore , extremely probable that they will have taken the places of , and thus exterminated , not only their ...
... stage of descent , so as to have become adapted to many related places in the natural economy of their country . It seems , therefore , extremely probable that they will have taken the places of , and thus exterminated , not only their ...
Página 131
... stage of perfection , so as to have given them a decided advantage over other animals in the battle for life . Hence the chance of discovering species with transitional grades of structure in a fossil condition will always be less ...
... stage of perfection , so as to have given them a decided advantage over other animals in the battle for life . Hence the chance of discovering species with transitional grades of structure in a fossil condition will always be less ...
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Términos y frases comunes
accumulated adapted admit affinities allied species America analogous ancient appear beak become bees believe belonging birds breeds cause cells characters climate closely allied colour continued crossed crustaceans degree developed difficulty distinct species domestic animals doubt effects eggs embryo existing extinct extremely facts favourable female fertilised fertility flowers formation formerly forms fossil Fritz Müller genera genus geological geological period Glacial period gradations greater number habits Hence hybrids 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 occur oceanic islands offspring organisation organs parent peculiar perfect pigeon pistil pollen present preserved principle probably produced quadrupeds ranked reciprocal crosses remarked resemblance rudimentary seeds sexual selection Silurian slight South America stamens sterility structure successive supposed tend theory tion variability variations varieties vary whilst whole wings young