On the Origin of Species by Means of Natural Selection: Or The Preservation of Favored Races in the Struggle for Life, Volumen2D. Appleton, 1888 - 458 páginas |
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Página 12
... 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 24
... 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 observing the accumulated effects of selecticn - 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 observing the accumulated effects of selecticn - namely , by ...
Página 25
... kind in the country . But , for our pur- pose , 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 pur- pose , 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 26
... kind of unconscious selection going on . We sec he 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 sec he 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 ...
Página 34
... kind ever do appear in a state of nature and are capable of reproduction ( which is not always the case ) , as they occur rarely and singly , their preservation would depend on unusually favourable circumstances . They would , also ...
... kind ever do appear in a state of nature and are capable of reproduction ( which is not always the case ) , as they occur rarely and singly , their preservation would depend on unusually favourable circumstances . They would , also ...
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Términos y frases comunes
adapted admit affinities allied species America analogous ancient appear Asa Gray beak become bees believe belonging birds breeds cause cells characters climate closely allied colour continued crossed crustaceans degree developed difficulty distinct species doubt effects eggs embryo existing extinct extremely facts favourable fertilised fertility flowers formation formerly forms fossil Fritz Müller genera genus geological geological period Glacial period gradations greater number habits Hence hybrids important individuals inhabitants inherited insects instance instincts intercrossing intermediate kind lamellæ larvæ less living male mammals manner Marsupials migration modified descendants natural selection naturalists nearly nest occasionally occur oceanic islands offspring organisation organs parent peculiar perfect pigeon pistil pollen present preserved principle probably produced quadrupeds ranked reciprocal crosses remarked reproductive resemblance rudimentary seeds sexual selection slight South America stamens sterility structure struggle successive supposed tend theory tion variability variations varieties vary whilst whole wings young