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 19
... kind truly , were the offspring of any single species , then such facts would have great weight in making us doubt about the immutability of the many closely allied natural species - for instance , of the many foxes - inhabiting ...
... kind truly , were the offspring of any single species , then such facts would have great weight in making us doubt about the immutability of the many closely allied natural species - for instance , of the many foxes - inhabiting ...
Página 37
... kind of selection is , in fact , likewise followed ; for hardly any one is so careless as to Breed from his worst animals . In regard to plants , there is another means of ob- serving the accumulated effects of selection — namely , by ...
... kind of selection is , in fact , likewise followed ; for hardly any one is so careless as to Breed from his worst animals . In regard to plants , there is another means of ob- serving the accumulated effects of selection — namely , by ...
Página 39
... kind in the country . But , for our purpose , a form of Selection , which may be called Unconscious , and which results from every one trying to possess and breed from the best individual animals , is more important . Thus , a man who ...
... kind in the country . But , for our purpose , a form of Selection , which may be called Unconscious , and which results from every one trying to possess and breed from the best individual animals , is more important . Thus , a man who ...
Página 40
... kind can never be recognised unless actual measurements or careful drawings of the breeds in question have been made long ago , which may serve for comparison . In some cases , however , unchanged , or but little changed individuals of ...
... kind can never be recognised unless actual measurements or careful drawings of the breeds in question have been made long ago , which may serve for comparison . In some cases , however , unchanged , or but little changed individuals of ...
Página 41
... kind of unconscious selection going on . We see the value set on animals even by the barbarians of Tierra del Fuego , by their killing and devouring their old women , in times of dearth , as of less value than their dogs . In plants the ...
... kind of unconscious selection going on . We see the value set on animals even by the barbarians of Tierra del Fuego , by their killing and devouring their old women , in times of dearth , as of less value than their dogs . In plants the ...
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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