The Origin of Species by Means of Natural Selection,: Or the Preservation of Favoured Races in the Struggle for LifeAppleton, 1898 - 432 páginas |
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Página 49
... common but unknown progenitor ; and the progenitor will gen- erally have differed in some respects from all its modi- fied descendants . To give a simple illustration : the fantail and pouter pigeons are both descended from the rock ...
... common but unknown progenitor ; and the progenitor will gen- erally have differed in some respects from all its modi- fied descendants . To give a simple illustration : the fantail and pouter pigeons are both descended from the rock ...
Página 93
... common progenitor . In the genus Lingula , for instance , the species which have successively appeared at all ages must have been connected by an unbroken series of generations , from the lowest Silurian stratum to the present day . We ...
... common progenitor . In the genus Lingula , for instance , the species which have successively appeared at all ages must have been connected by an unbroken series of generations , from the lowest Silurian stratum to the present day . We ...
Página 110
... common from their ancient progenitor . On the principle of the continued tendency to divergence of character , which was formerly illustrated by this diagram , the more recent any form is , the more it will generally differ from its ...
... common from their ancient progenitor . On the principle of the continued tendency to divergence of character , which was formerly illustrated by this diagram , the more recent any form is , the more it will generally differ from its ...
Página 112
... common progenitor . Thus it comes that ancient and extinct genera are often in a greater or less degree intermediate in character between their modified descendants , or between their collateral relations . Under nature the process will ...
... common progenitor . Thus it comes that ancient and extinct genera are often in a greater or less degree intermediate in character between their modified descendants , or between their collateral relations . Under nature the process will ...
Página 126
... common progenitor , tend to become extinct together , and to leave no modi- fied offspring on the face of the earth . But the utter extinction of a whole group of species has sometimes been a slow process , from the survival of a few ...
... common progenitor , tend to become extinct together , and to leave no modi- fied offspring on the face of the earth . But the utter extinction of a whole group of species has sometimes been a slow process , from the survival of a few ...
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Términos y frases comunes
admit affinity allied species ancient animals appear Archipelago arctic areas become believe birds Cambrian changes characters cies classification climate closely allied common progenitor continent crustaceans degree deposited difficulty distant distinct species domestic doubt embryo eral Europe existing extinct fact faunas fertilised fertility flowers formations formerly forms fossil fresh-water Fritz Müller Gärtner genera genus geological period geological record Glacial period groups of species habits hybrids hybrids produced important individuals inhabitants inherited insects instance intermediate intervals land larvæ less living mammals manner marine Marsupials migration modified descendants mongrels mountains natural selection naturalists nearly occur oceanic islands offspring organisation parent parent-form peculiar perfect pistil plants pollen present probably produced quadrupeds reciprocal crosses regions remains remarked reproductive resemblance rocks rudimentary organs sediment seeds Silurian South America stage stamens sterility structure successive suppose terrestrial tertiary theory tion variations varieties whilst widely different wings