On the Origin of Species by Means of Natural Selection: Or The Preservation of Favoured Races in the Struggle for LifeHumphrey Milford, Oxford University Press, 1923 - 454 páginas |
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Página 4
... individuals of each species are born than can possibly survive ; and as , consequently , there is a frequently recurring struggle for existence , it follows that any being , if it vary however slightly in any manner profit- able to ...
... individuals of each species are born than can possibly survive ; and as , consequently , there is a frequently recurring struggle for existence , it follows that any being , if it vary however slightly in any manner profit- able to ...
Página 9
... individuals , though taken young from a state of nature , perfectly tamed , long - lived , and healthy ( of which I could give numerous instances ) , yet having their reproductive system so seriously affected by un- perceived causes as ...
... individuals , though taken young from a state of nature , perfectly tamed , long - lived , and healthy ( of which I could give numerous instances ) , yet having their reproductive system so seriously affected by un- perceived causes as ...
Página 10
... individuals exposed to certain conditions are affected in the same way , the change at first appears to be directly due to such conditions ; but in some cases it can be shown that quite opposite conditions produce similar changes of ...
... individuals exposed to certain conditions are affected in the same way , the change at first appears to be directly due to such conditions ; but in some cases it can be shown that quite opposite conditions produce similar changes of ...
Página 11
... individuals by certain vegetable poisons . Hairless dogs have imperfect teeth ; long - haired and coarse - haired animals are apt to have , as is asserted , long or many horns ; pigeons with feathered feet have skin between their outer ...
... individuals by certain vegetable poisons . Hairless dogs have imperfect teeth ; long - haired and coarse - haired animals are apt to have , as is asserted , long or many horns ; pigeons with feathered feet have skin between their outer ...
Página 12
... individuals — and it reappears in the child , the mere doctrine of chances almost compels us to attribute its ... individuals of the same species , or in individuals of different species , is sometimes inherited and sometimes not so ...
... individuals — and it reappears in the child , the mere doctrine of chances almost compels us to attribute its ... individuals of the same species , or in individuals of different species , is sometimes inherited and sometimes not so ...
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Términos y frases comunes
accumulated adapted affinities allied species America amount analogous ancient appear Archipelago become bees believe birds breeds cause cells characters cirripedes climate closely allied colour common parent continuous crossed crustaceans degree difficulty distinct species divergence doubt embryo endemic Europe existing exterminated extinct extremely facts favourable fertility flowers formations forms fossil Gärtner genera genus geological geological period Glacial period gradations greater number groups of species habits Hence hermaphrodites hybrids hybrids produced important individuals inhabitants inherited insects instance instincts intercrossing land larvæ less living male mammals manner Marsupials migration modification modified descendants natural selection naturalists nearly nest oceanic islands offspring organisation perfect pigeons pistil plants pollen present principle probably produced progenitor ranked reciprocal crosses remarked resemble rock-pigeon rudimentary organs seeds sexual selection Silurian slight South America sterility structure struggle successive suppose swimbladder tend theory tion trees variability variation vary whole widely