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 4
... artificial selection . Herbert Spencer maintains that the effects of use and disuse are inherited in kind , and in his Factors of Organic Evolution1 he has supported his contention with a selection of facts and reason- ings which I ...
... artificial selection . Herbert Spencer maintains that the effects of use and disuse are inherited in kind , and in his Factors of Organic Evolution1 he has supported his contention with a selection of facts and reason- ings which I ...
Página 13
... artificial selection because the modifica- tions offer no appreciable external signs . Surely hard biting is sufficiently appreciable by the person bitten without any visual admeasurement of the masseter muscles or the zygomatic arches ...
... artificial selection because the modifica- tions offer no appreciable external signs . Surely hard biting is sufficiently appreciable by the person bitten without any visual admeasurement of the masseter muscles or the zygomatic arches ...
Página 14
... artificial selection of shortened jaws . If a similar change is really occurring in man , could it not be similarly explained by some factor , such as sexual selection , which might affect the outward appearance at the cost of less ...
... artificial selection of shortened jaws . If a similar change is really occurring in man , could it not be similarly explained by some factor , such as sexual selection , which might affect the outward appearance at the cost of less ...
Página 15
... artificial drink such as cyder , from sugar , from medicine , and from vitiated secretions of the mouth . It is evident that in civilized races natural selection cannot so rigorously insist on sound teeth , sound constitutions , and ...
... artificial drink such as cyder , from sugar , from medicine , and from vitiated secretions of the mouth . It is evident that in civilized races natural selection cannot so rigorously insist on sound teeth , sound constitutions , and ...
Página 21
... artificial selection of complicated variations has modified animals in many points either simultaneously or by slow steps , as with otter - sheep , fancy pigeons , & c . ( many of the characters thus obtained being clearly independent ...
... artificial selection of complicated variations has modified animals in many points either simultaneously or by slow steps , as with otter - sheep , fancy pigeons , & c . ( many of the characters thus obtained being clearly independent ...
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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.