The Origin of Species by Means of Natural Selection: Or the Preservation of Favored Races in the Struggle for LifeD. Appleton, 1904 - 435 páginas |
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Página 93
... manner as beings in a state of nature , and if the seed or young were not annually preserved in due proportion . Struggle for Life most severe between Individuals and Varieties of the same Species . As the species of the same genus ...
... manner as beings in a state of nature , and if the seed or young were not annually preserved in due proportion . Struggle for Life most severe between Individuals and Varieties of the same Species . As the species of the same genus ...
Página 95
... manner , although the climate may be exactly the same as in its former home . If its average numbers are to increase in its new home , we should have to modify it in a different way to what we should have had to do in its native country ...
... manner , although the climate may be exactly the same as in its former home . If its average numbers are to increase in its new home , we should have to modify it in a different way to what we should have had to do in its native country ...
Página 100
... manner in which the inhabitants of each country are bound together , that any change in the numerical proportions of the inhabitants , independently of the change of climate itself , would seriously affect the others . If the country ...
... manner in which the inhabitants of each country are bound together , that any change in the numerical proportions of the inhabitants , independently of the change of climate itself , would seriously affect the others . If the country ...
Página 102
... manner ; he feeds a long and a short beaked pigeon on the same food ; he does not exercise a long - backed or long - legged quadruped in any peculiar manner ; he exposes sheep with long and short wool to the same climate . He does not ...
... manner ; he feeds a long and a short beaked pigeon on the same food ; he does not exercise a long - backed or long - legged quadruped in any peculiar manner ; he exposes sheep with long and short wool to the same climate . He does not ...
Página 106
... number of eggs or seeds are annually devoured , and these could be modified . through natural selection only if they varied in some manner which protected them from their enemies . Yet many 106 [ CHAP . IV . NATURAL SELECTION .
... number of eggs or seeds are annually devoured , and these could be modified . through natural selection only if they varied in some manner which protected them from their enemies . Yet many 106 [ CHAP . IV . NATURAL SELECTION .
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Términos y frases comunes
adapted affinities allied species America ancient appear Asa Gray beak become bees believe belonging birds breeds cause cells characters climate closely allied colour common continent crossed crustaceans degree developed difficulty distinct species domestic doubt effects eggs embryo existing extinct extremely facts favourable fertilised fertility flowers formation forms fossil Fritz Müller genera genus geological geological period Glacial period gradations greater number groups of species habits Hence hybrids important individuals inhabitants inherited insects instance instincts intercrossing intermediate kind lamellæ larvæ less living males mammals manner marsupials migration modified descendants natural selection naturalists nearly nest occasionally offspring organisation organs parent peculiar perfect pigeon pistil pollen present principle probably produced progenitor quadrupeds ranked remarked resemblance rudimentary seeds sexual selection Silurian slight South America stamens sterility structure successive supposed swimbladder tend theory tion trees variability variations varieties vary whilst whole wings young