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 9
... suppose that disuse would maintain or develop . the projecting chin , increase its perpendicular height till the jaw is deepest and strongest at its extremity , evolve a side flange , and enlarge the upper jaw - bone to form part of a ...
... suppose that disuse would maintain or develop . the projecting chin , increase its perpendicular height till the jaw is deepest and strongest at its extremity , evolve a side flange , and enlarge the upper jaw - bone to form part of a ...
Página 14
... suppose that the size of the human teeth is maintained by use at the same time that the jaws are being diminished by disuse ? Mr. Spencer acknowledges that the crowding of bull - dogs ' and lap - dogs ' teeth is caused by the artificial ...
... suppose that the size of the human teeth is maintained by use at the same time that the jaws are being diminished by disuse ? Mr. Spencer acknowledges that the crowding of bull - dogs ' and lap - dogs ' teeth is caused by the artificial ...
Página 29
... suppose that " minor traits " such as the " æsthetic perceptions " cannot have been evolved by natural selection ( p . 20 ) or by sexual selec- tion ? Darwin holds that our musical faculties were developed by sexual preference long ...
... suppose that " minor traits " such as the " æsthetic perceptions " cannot have been evolved by natural selection ( p . 20 ) or by sexual selec- tion ? Darwin holds that our musical faculties were developed by sexual preference long ...
Página 33
... suppose that the effect of the adult practice of parents was in- herited at this early age ? If use - inheritance was not necessary in the case of Handel , whose father was a surgeon , why is it needed to account for Bach ? D LACK OF ...
... suppose that the effect of the adult practice of parents was in- herited at this early age ? If use - inheritance was not necessary in the case of Handel , whose father was a surgeon , why is it needed to account for Bach ? D LACK OF ...
Página 69
... suppose that use - inherit- ance especially affects the eight breeds that have varied most in size . If we exclude these , there is only a total shortening of 7 per cent . to be accounted for . SHORTENED FEET IN PIGEONS . Darwin thinks ...
... suppose that use - inherit- ance especially affects the eight breeds that have varied most in size . If we exclude these , there is only a total shortening of 7 per cent . to be accounted for . SHORTENED FEET IN PIGEONS . Darwin thinks ...
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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.