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 10
... extremely improbable . The heavier skull and narrower molar teeth point however to other factors than increased use . The striking variability of the human jaw is strongly opposed 10 ARE THE EFFECTS OF USE INHERITED ?
... extremely improbable . The heavier skull and narrower molar teeth point however to other factors than increased use . The striking variability of the human jaw is strongly opposed 10 ARE THE EFFECTS OF USE INHERITED ?
Página 11
... female jaws and skulls evidently points to 1 Inclusive in each case of fixed strengthening wire weighing about a sixteenth of an ounce or less . sexual selection and to panmixia under male protection . I DIMINUTION OF THE JAWS . II.
... female jaws and skulls evidently points to 1 Inclusive in each case of fixed strengthening wire weighing about a sixteenth of an ounce or less . sexual selection and to panmixia under male protection . I DIMINUTION OF THE JAWS . II.
Página 14
... points to the decay of modern teeth as a sign or result of their being overcrowded 1 References of course are to Factors of Organic Evolution . through the diminution of the jaw by disuse.1 But the 14 ARE THE EFFECTS OF USE INHERITED ...
... points to the decay of modern teeth as a sign or result of their being overcrowded 1 References of course are to Factors of Organic Evolution . through the diminution of the jaw by disuse.1 But the 14 ARE THE EFFECTS OF USE INHERITED ...
Página 21
... points either simultaneously or by slow steps , as with otter - sheep , fancy pigeons , & c . ( many of the characters thus obtained being clearly independent of use and disuse ) , natural selection must be credited with similar powers ...
... points either simultaneously or by slow steps , as with otter - sheep , fancy pigeons , & c . ( many of the characters thus obtained being clearly independent of use and disuse ) , natural selection must be credited with similar powers ...
Página 22
... points simultaneously , although no one of them may be of greater importance than the rest . Of course the more complicated the evolution the slower it will be ; but time is plentiful , and the amount of elimination is correspondingly ...
... points simultaneously , although no one of them may be of greater importance than the rest . Of course the more complicated the evolution the slower it will be ; but time is plentiful , and the amount of elimination is correspondingly ...
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.