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 139
... theory , for an immense period in nearly the same state ; and thus it comes to be no more variable than any other structure . It is only in those cases in which the modification has been comparatively recent and extraordinarily great ...
... theory , for an immense period in nearly the same state ; and thus it comes to be no more variable than any other structure . It is only in those cases in which the modification has been comparatively recent and extraordinarily great ...
Página 146
... theory , to have descended from a common parent , it might be expected that they would occasionally vary in an analogous manner ; so that a variety of one species would resemble in some of its characters another species ; this other ...
... theory , to have descended from a common parent , it might be expected that they would occasionally vary in an analogous manner ; so that a variety of one species would resemble in some of its characters another species ; this other ...
Página 149
... theory , and should be loth to apply it to breeds so distinct as the heavy Belgian cart - horse , Welch ponies , cobs , the lanky Kattywar race , etc. , in- habiting the most distant parts of the world . Now let us turn to the effects ...
... theory , and should be loth to apply it to breeds so distinct as the heavy Belgian cart - horse , Welch ponies , cobs , the lanky Kattywar race , etc. , in- habiting the most distant parts of the world . Now let us turn to the effects ...
Página 153
... which the innumerable beings on the face of this earth are enabled to struggle with each other , and the best adapted to survive . CHAPTER VI DIFFICULTIES ON THEORY Difficulties on the theory of LAWS OF VARIATION 153.
... which the innumerable beings on the face of this earth are enabled to struggle with each other , and the best adapted to survive . CHAPTER VI DIFFICULTIES ON THEORY Difficulties on the theory of LAWS OF VARIATION 153.
Página 154
... THEORY Difficulties on the theory of descent with modification -- Transitions- Absence or rarity of transitional varieties - Transitions in habits of life - Diversified habits in the same species - Species with habits widely different ...
... THEORY Difficulties on the theory of descent with modification -- Transitions- Absence or rarity of transitional varieties - Transitions in habits of life - Diversified habits in the same species - Species with habits widely different ...
Otras ediciones - Ver todas
On the Origin of Species by Means of Natural Selection: or the Preservation ... Charles Darwin Vista previa limitada - 2023 |
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