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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Página 15
... greater degree , to the males alone . A much more important rule , which I think may be trusted , is that , at whatever period of life a peculiarity first appears , it tends to reappear in the offspring at a corresponding age , though.
... greater degree , to the males alone . A much more important rule , which I think may be trusted , is that , at whatever period of life a peculiarity first appears , it tends to reappear in the offspring at a corresponding age , though.
Página 29
... greater number of generations . In a breed which has been crossed only once , the tendency to revert to any character derived from such a cross will naturally become less and less , as in each suc- ceeding generation there will be less ...
... greater number of generations . In a breed which has been crossed only once , the tendency to revert to any character derived from such a cross will naturally become less and less , as in each suc- ceeding generation there will be less ...
Página 49
... greater or less force of inheritance and reversion determine whether variations shall endure . Variability is governed by many unknown laws , of which correlated growth is probably the most important . Something , but how much we do not ...
... greater or less force of inheritance and reversion determine whether variations shall endure . Variability is governed by many unknown laws , of which correlated growth is probably the most important . Something , but how much we do not ...
Página 59
... greater amount of differ- ence than that between the local forms and sub - species , they are almost universally ranked by naturalists as true species . Nevertheless , no certain criterion can possibly be given by which variable forms ...
... greater amount of differ- ence than that between the local forms and sub - species , they are almost universally ranked by naturalists as true species . Nevertheless , no certain criterion can possibly be given by which variable forms ...
Página 62
... the result of so much labour , he emphatically remarks : " They are mistaken , who repeat that the greater part of our species are clearly limited , and that the doubtful species are in a. 62 [ CHAP . II . DOUBTFUL SPECIES .
... the result of so much labour , he emphatically remarks : " They are mistaken , who repeat that the greater part of our species are clearly limited , and that the doubtful species are in a. 62 [ CHAP . II . DOUBTFUL SPECIES .
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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