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 vii
... stages of useful structures -Causes which interfere with the acquisition through natural selection of useful structures - Gradations of structure with changed functions- Widely different organs in members of the same class , developed ...
... stages of useful structures -Causes which interfere with the acquisition through natural selection of useful structures - Gradations of structure with changed functions- Widely different organs in members of the same class , developed ...
Página xii
... stages of useful structures . There is also a discussion on the causes which prevent in many cases the acquisition through natural selection of useful structures . Lastly , reasons are given for disbelieving in great and sudden ...
... stages of useful structures . There is also a discussion on the causes which prevent in many cases the acquisition through natural selection of useful structures . Lastly , reasons are given for disbelieving in great and sudden ...
Página 10
... stage . But hereditary diseases and some other facts make me believe that the rule has a wider extension , and that , when there is no apparent reason why a peculiarity should appear at any particular age , yet that it does tend to ...
... stage . But hereditary diseases and some other facts make me believe that the rule has a wider extension , and that , when there is no apparent reason why a peculiarity should appear at any particular age , yet that it does tend to ...
Página 24
... stages through which they have insensibly passed , and come to differ so greatly from the rock - pigeon . Youatt gives an excellent illustration of the effects of a course of selection , which may be considered as unconscious , in so ...
... stages through which they have insensibly passed , and come to differ so greatly from the rock - pigeon . Youatt gives an excellent illustration of the effects of a course of selection , which may be considered as unconscious , in so ...
Página 39
... stage of difference to another may , in many cases , be the simple result of the nature of the organism and of the different physical conditions to which it has long been ex- posed ; but with respect to the more important and adaptive ...
... stage of difference to another may , in many cases , be the simple result of the nature of the organism and of the different physical conditions to which it has long been ex- posed ; but with respect to the more important and adaptive ...
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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