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 xi
... VARIED EFFECTS OF USE AND DISUSE USE - INHERITANCE IMPLIES PANGENESIS PANGENESIS IMPROBABLE . · • · · 127 128 134 137 • · 138 SPENCER'S EXPLANATION OF USE - INHERITANCE 141 CONCLUSIONS . PAGE 144-156 USE - INHERITANCE DISCREDITED AS ...
... VARIED EFFECTS OF USE AND DISUSE USE - INHERITANCE IMPLIES PANGENESIS PANGENESIS IMPROBABLE . · • · · 127 128 134 137 • · 138 SPENCER'S EXPLANATION OF USE - INHERITANCE 141 CONCLUSIONS . PAGE 144-156 USE - INHERITANCE DISCREDITED AS ...
Página 11
... varied from 19 oz . to 4'3 oz . ( or 5 oz . if lost teeth were allowed for ) ; Australian jaws varied from 2 oz . to 4'5 oz . ( with no lost teeth to allow for ) ; while in Negro jaws the maximum rose to over 5 oz.1 In spite of disuse ...
... varied from 19 oz . to 4'3 oz . ( or 5 oz . if lost teeth were allowed for ) ; Australian jaws varied from 2 oz . to 4'5 oz . ( with no lost teeth to allow for ) ; while in Negro jaws the maximum rose to over 5 oz.1 In spite of disuse ...
Página 21
... varied in kind . " While co- operative parts would often be more or less correlated , so that they would tend to vary to- gether , coincident variation is not necessary . The lengthened wing might be gained in one genera- tion , and the ...
... varied in kind . " While co- operative parts would often be more or less correlated , so that they would tend to vary to- gether , coincident variation is not necessary . The lengthened wing might be gained in one genera- tion , and the ...
Página 58
... great that the wing - bones are 47 per cent . heavier than they should be if their weight had varied proportionally with their length.1 The reduction in weight on which Darwin relies seems 58 ARE THE EFFECTS OF USE INHERITED ?
... great that the wing - bones are 47 per cent . heavier than they should be if their weight had varied proportionally with their length.1 The reduction in weight on which Darwin relies seems 58 ARE THE EFFECTS OF USE INHERITED ?
Página 69
... 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 it highly probable PIGEON'S BREAST - BONE . 69.
... 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 it highly probable PIGEON'S BREAST - BONE . 69.
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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
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.