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 122
... period when the several species branched off from the common progenitor of the genus . This period will seldom be remote in any extreme degree , as species rarely endure for more than one geological period . An extraordinary amount of ...
... period when the several species branched off from the common progenitor of the genus . This period will seldom be remote in any extreme degree , as species rarely endure for more than one geological period . An extraordinary amount of ...
Página 344
... period . At this , the newer Pliocene period , the majority of the inhabitants of the world were specifically the same as now , and we have good reason to believe that the climate was warmer than at the present day . Hence we may ...
... period . At this , the newer Pliocene period , the majority of the inhabitants of the world were specifically the same as now , and we have good reason to believe that the climate was warmer than at the present day . Hence we may ...
Página 405
... period of growth alike ; the common , but not invariable , resemblance between the embryos or larvæ of the most distinct species in the same class ; -the embryo often retaining , whilst within the egg or womb , structures which are of ...
... period of growth alike ; the common , but not invariable , resemblance between the embryos or larvæ of the most distinct species in the same class ; -the embryo often retaining , whilst within the egg or womb , structures which are of ...
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