The Origin of Species by Means of Natural Selection: Or, the Preservation of Favored Races in the Struggle for Life, Volumen1D. Appleton, 1898 |
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... considered . The statement with respect to young cuckoos ejecting their foster - brothers confirmed . On the cuckoo - like habits of the Molothrus . On fertile hybrid moths . The discussion on the fertility of hybrids not having been ...
... considered . The statement with respect to young cuckoos ejecting their foster - brothers confirmed . On the cuckoo - like habits of the Molothrus . On fertile hybrid moths . The discussion on the fertility of hybrids not having been ...
Página 5
... considered . This is the doctrine of Malthus , applied to the whole animal and vegetable kingdoms . As many more individuals of each species are born than can possibly survive ; and as , consequently , there is a frequently recurring ...
... considered . This is the doctrine of Malthus , applied to the whole animal and vegetable kingdoms . As many more individuals of each species are born than can possibly survive ; and as , consequently , there is a frequently recurring ...
Página 8
... considered as defi- nite when all or nearly all the offspring of individuals exposed to certain conditions during several generations are modified in the same manner . It is extremely difficult to come to any conclusion in regard to the ...
... considered as defi- nite when all or nearly all the offspring of individuals exposed to certain conditions during several generations are modified in the same manner . It is extremely difficult to come to any conclusion in regard to the ...
Página 9
... of structure , whether extremely slight or strongly marked , which appear amongst many individuals living together , may be considered as the indefinite effects of the conditions of life on. CHAP . I. ] VARIATION UNDER DOMESTICATION . 9.
... of structure , whether extremely slight or strongly marked , which appear amongst many individuals living together , may be considered as the indefinite effects of the conditions of life on. CHAP . I. ] VARIATION UNDER DOMESTICATION . 9.
Página 41
... considered as unconscious , in so far that the breeders could never have expected , or even wished , to produce the result which ensued - namely , the production of two distinct strains . The two flocks of Leicester sheep kept by Mr ...
... considered as unconscious , in so far that the breeders could never have expected , or even wished , to produce the result which ensued - namely , the production of two distinct strains . The two flocks of Leicester sheep kept by Mr ...
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Términos y frases comunes
adapted advantage allied analogous animals and plants appear Asa Gray beak become bees believe birds breeds caudicle cause cells characters climate closely colour common crossed cuckoo degree descendants developed difficulty distinct species disuse divergence domestic animals domestic races doubt effects eggs existence extinct extremely facts favourable females flowers forms Fritz Müller genera genus giraffe gradations greater number groups habits Hence hermaphrodites hive-bee important increase inhabitants inherited insects instance instincts intercrossing intermediate kind lamellæ large number larger genera larvæ less males manner Melipona Mivart modified natural selection naturalists nearly nest occasionally offspring organisation organs origin Origin of Species parent perfect period pigeons pollen pollen-grains present preserved prey principle probably produced progenitor quadrupeds rank rarely Red Grouse relation remarked resemble rock-pigeon seeds sexes sexual selection slight stamens striped structure struggle supposed swimbladder tend tendency tion tree variability variations varieties vary widely wings young