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 3
... cause of variation . In one very limited sense , as we shall hereafter see , this may be true ; but it is pre- posterous to attribute to mere external conditions the structure , for instance , of the woodpecker , with its feet , tail ...
... cause of variation . In one very limited sense , as we shall hereafter see , this may be true ; but it is pre- posterous to attribute to mere external conditions the structure , for instance , of the woodpecker , with its feet , tail ...
Página 4
... shall then see how Natural Selection almost in- evitably causes much Extinction of the less improved forms of life , and leads to what I have called Divergence of Character . In the next chapter I shall discuss 4 ON THE ORIGIN OF SPECIES.
... shall then see how Natural Selection almost in- evitably causes much Extinction of the less improved forms of life , and leads to what I have called Divergence of Character . In the next chapter I shall discuss 4 ON THE ORIGIN OF SPECIES.
Página 8
... causes monstrosities ; and monstrosities cannot be separated by any clear line of distinction from mere variations . But I am strongly inclined to suspect that the most frequent cause of variability may be attributed to the male and ...
... causes monstrosities ; and monstrosities cannot be separated by any clear line of distinction from mere variations . But I am strongly inclined to suspect that the most frequent cause of variability may be attributed to the male and ...
Página 9
... causes as to fail in acting , we need not be surprised at this system , when it does act under con- finement ... cause which produces sterility ; and variability is the source of all the choicest productions of the garden . I may ...
... causes as to fail in acting , we need not be surprised at this system , when it does act under con- finement ... cause which produces sterility ; and variability is the source of all the choicest productions of the garden . I may ...
Página 12
... cause having acted on both ; but when amongst individuals , apparently exposed to the same conditions , any very rare deviation , due to some extraordinary combination of circumstances , appears in the parent - say , once amongst ...
... cause having acted on both ; but when amongst individuals , apparently exposed to the same conditions , any very rare deviation , due to some extraordinary combination of circumstances , appears in the parent - say , once amongst ...
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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