Are the Effects of Use and Disuse Inherited?: An Examination of the View Held by Spencer and DarwinMacmillan, 1890 - 156 páginas |
Dentro del libro
Resultados 1-5 de 12
Página 13
... excluding economy of nutrition from the problem . Breeders would not over - feed these dogs ; and the puppies that grew most rapidly would usually be favoured . CROWDED TEETH . " " The too closely - packed LAP - DOGS ' JAWS . 13.
... excluding economy of nutrition from the problem . Breeders would not over - feed these dogs ; and the puppies that grew most rapidly would usually be favoured . CROWDED TEETH . " " The too closely - packed LAP - DOGS ' JAWS . 13.
Página 36
... usually accompanies , but which Mr. Spencer does not mention . INHERITED INSANITY AND NERVOUS DISORDERS . Mr. Spencer infers that , because insanity is usually hereditary , and insanity can be artificially produced by various excesses ...
... usually accompanies , but which Mr. Spencer does not mention . INHERITED INSANITY AND NERVOUS DISORDERS . Mr. Spencer infers that , because insanity is usually hereditary , and insanity can be artificially produced by various excesses ...
Página 55
... usually favour these adap- tive changes , and they would also have been aided by an artificial selection which is often unconscious or indirect . Birds with diminished power of flight would be less difficult to keep and manage , and in ...
... usually favour these adap- tive changes , and they would also have been aided by an artificial selection which is often unconscious or indirect . Birds with diminished power of flight would be less difficult to keep and manage , and in ...
Página 60
... skeletons , thus furnishing the means for a closer examination of his details than is usually possible . If we ignore such factors as selection , pan- mixia , correlation , and the effects of use and 60 ARE THE EFFECTS OF USE INHERITED ?
... skeletons , thus furnishing the means for a closer examination of his details than is usually possible . If we ignore such factors as selection , pan- mixia , correlation , and the effects of use and 60 ARE THE EFFECTS OF USE INHERITED ?
Página 77
... usually killed off the wildest and bred from the tamest and most manageable . To some extent he has done this consciously . " It is very conducive to successful breeding to keep only such as are quiet and tractable , " says an authority ...
... usually killed off the wildest and bred from the tamest and most manageable . To some extent he has done this consciously . " It is very conducive to successful breeding to keep only such as are quiet and tractable , " says an authority ...
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.