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 8
... relative lightness and smallness of the latter , especially in the higher races . Human preference , both sexual and social , would tend to eliminate huge jaws and ferocious teeth when these were no longer needed as weapons of war or ...
... relative lightness and smallness of the latter , especially in the higher races . Human preference , both sexual and social , would tend to eliminate huge jaws and ferocious teeth when these were no longer needed as weapons of war or ...
Página 57
... relative shortening is attributed to a heavier 1 Variation of Animals and Plants under Domestication , i . 299- 301 . 2 To keep pace with this lateral increase in weight , the leg - bones should have lengthened considerably so that ...
... relative shortening is attributed to a heavier 1 Variation of Animals and Plants under Domestication , i . 299- 301 . 2 To keep pace with this lateral increase in weight , the leg - bones should have lengthened considerably so that ...
Página 63
... relative reduction in the wings as with the Pouter , where the wings have been greatly lengthened but not SO much as the body.2 Slender bodies , too , and the lessened divergence of the furculum , 3 would 1 Variation of Animals and ...
... relative reduction in the wings as with the Pouter , where the wings have been greatly lengthened but not SO much as the body.2 Slender bodies , too , and the lessened divergence of the furculum , 3 would 1 Variation of Animals and ...
Página 65
... relative shortening of the sternum remained otherwise inexplicable , it might still be as irrelevant to use and disuse as is the fact that " many breeds " of fancy pigeons have lost a rib , having only seven where the ancestral rock ...
... relative shortening of the sternum remained otherwise inexplicable , it might still be as irrelevant to use and disuse as is the fact that " many breeds " of fancy pigeons have lost a rib , having only seven where the ancestral rock ...
Página 66
... relative change must be attri- buted to the lengthening of the neck or body by 1 Variation of Animals and Plants under Domestication , i . 184 . I suspect that Darwin was in poor health when he wrote this page . He nods at least four ...
... relative change must be attri- buted to the lengthening of the neck or body by 1 Variation of Animals and Plants under Domestication , i . 184 . I suspect that Darwin was in poor health when he wrote this page . He nods at least four ...
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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
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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.