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 101
... complex relations , namely on the variations which have arisen , these being due to causes far too intricate to be followed out , on the nature of the variations which have been preserved or selected , and this depends on the ...
... complex relations , namely on the variations which have arisen , these being due to causes far too intricate to be followed out , on the nature of the variations which have been preserved or selected , and this depends on the ...
Página 213
... complex instinct can possibly be produced through natural Instincts graduated selection , except by the slow and gradual accumulation of numerous slight , yet profitable , variations . Hence , as in the case of corporeal structures , we ...
... complex instinct can possibly be produced through natural Instincts graduated selection , except by the slow and gradual accumulation of numerous slight , yet profitable , variations . Hence , as in the case of corporeal structures , we ...
Página 300
... complex contingencies - on the variations being of a beneficial nature , on the freedom of intercrossing , on the slowly changing physical conditions of the country , on the immigration of new colonists , and on the nature of the other ...
... complex contingencies - on the variations being of a beneficial nature , on the freedom of intercrossing , on the slowly changing physical conditions of the country , on the immigration of new colonists , and on the nature of the other ...
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