Are the Effects of Use and Disuse Inherited?: An Examination of the View Held by Spencer and DarwinMacmillan, 1890 - 156 páginas |
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Página 17
... eyes but not the disused eye - stalks appear to illus- trate the effects of natural selection rather than of disuse . The loss of the exposed , sensitive , and worse - than - useless eye , would be a decided gain , while the disused eye ...
... eyes but not the disused eye - stalks appear to illus- trate the effects of natural selection rather than of disuse . The loss of the exposed , sensitive , and worse - than - useless eye , would be a decided gain , while the disused eye ...
Página 18
... eye and its peduncle " ( pp . 12-14 , 23 , 33 ) . It escapes his notice , however , that in two out of his three cases it is disuse , or diminished use , which fails to cause concomitant variation or proportionate variation . THE ...
... eye and its peduncle " ( pp . 12-14 , 23 , 33 ) . It escapes his notice , however , that in two out of his three cases it is disuse , or diminished use , which fails to cause concomitant variation or proportionate variation . THE ...
Página 27
... eye in the midst of its forehead . In certain Mexican and Australian ants some of the neuters have huge spherical abdomens , which serve as living reservoirs of honey for the use of the community . In the equally wonderful case of the ...
... eye in the midst of its forehead . In certain Mexican and Australian ants some of the neuters have huge spherical abdomens , which serve as living reservoirs of honey for the use of the community . In the equally wonderful case of the ...
Página 44
... eyes and flaxen hair from their Anglo- Saxon ancestors , it by no means follows that an Englishman must inherit his father's sunburnt complexion or smooth - shaven face . Of course atavism ultimately adopts many instances of revolt ...
... eyes and flaxen hair from their Anglo- Saxon ancestors , it by no means follows that an Englishman must inherit his father's sunburnt complexion or smooth - shaven face . Of course atavism ultimately adopts many instances of revolt ...
Página 72
... eyes are useless or disadvantageous , as with parasites . This may apparently be done independently of the effects of disuse , for certain neuter ants have eyes which are reduced to a more or less rudimentary condition , and neuter ...
... eyes are useless or disadvantageous , as with parasites . This may apparently be done independently of the effects of disuse , for certain neuter ants have eyes which are reduced to a more or less rudimentary condition , and neuter ...
Otras ediciones - Ver todas
Términos y frases comunes
acquired characters acquired modifications alleged Animals and Plants appears artificial selection atavism attributed Aylesbury duck become birds bones breeds cause cent civilization concomitant variation Contemporary Review Crown 8vo cumulative Darwin Descent deterioration diminished diminution diseases domestic animals domestic rabbit duck effects of ancestral effects of disuse enlarged epilepsy evidence evil explanation eyes fact factor of evolution fancy pigeons father favoured Francis Darwin Francis Galton Galton gemmules guinea-pigs heredity Illustrations improvement incisors increased individual inherited effects inherited injuries inherited mutilations insects instances instincts jaws Lamarckian leg-bones legs lengthened muscles natural or artificial natural selection nervous neuter offspring organs Origin of Species pangenesis panmixia parents pigeons Plants under Domestication quasi-inheritance race Ray Lankester reduced wings relative reproductive elements sexual selection shortened Spencer spite of disuse spontaneous variations sternum structure suppose tameness teeth tend tendency theory thickened sole tion toes transmit true inheritance use-inheritance Variation of Animals weight Weismann wing-bones
Pasajes populares
Página 26 - For peculiar habits confined to the workers or sterile females, however long they might be followed, could not possibly affect the males and fertile females, which alone leave descendants. I am surprised that no one has hitherto advanced this demonstrative case of neuter insects, against the well-known doctrine of inherited habit, as advanced by Lamarck.