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 65
... adult . So , conversely , modifications in the adult may affect the structure of the larva ; but in all cases natural selection will ensure that they shall not be injurious : for if they were so , the species would become extinct ...
... adult . So , conversely , modifications in the adult may affect the structure of the larva ; but in all cases natural selection will ensure that they shall not be injurious : for if they were so , the species would become extinct ...
Página 408
... adult structure would be favoured by natural selection ; and all traces of former metamorphoses would finally be lost . If , on the other hand , it profited the young of an animal to follow habits of life slightly different from those ...
... adult structure would be favoured by natural selection ; and all traces of former metamorphoses would finally be lost . If , on the other hand , it profited the young of an animal to follow habits of life slightly different from those ...
Página 410
... adult . In two or more groups of animals , however much they may differ from each other in structure and habits in their adult condition , if they pass through closely similar embryonic stages , we may feel assured that they all are ...
... adult . In two or more groups of animals , however much they may differ from each other in structure and habits in their adult condition , if they pass through closely similar embryonic stages , we may feel assured that they all are ...
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