On the Origin of Species by Means of Natural Selection: Or The Preservation of Favoured Races in the Struggle for LifeHumphrey Milford, Oxford University Press, 1923 - 454 páginas |
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Página 47
... kind of variation to which the group is subject ; and this shows , at least , how very generally there is some variation . But if he confine his attention to one class within one country , he will soon make up his mind how to rank most ...
... kind of variation to which the group is subject ; and this shows , at least , how very generally there is some variation . But if he confine his attention to one class within one country , he will soon make up his mind how to rank most ...
Página 64
... kind of food . Even when climate , for instance extreme cold , acts directly , it will be the least vigorous , or those which have got least food through the advanc- ing winter , which will suffer most . When we travel from south to ...
... kind of food . Even when climate , for instance extreme cold , acts directly , it will be the least vigorous , or those which have got least food through the advanc- ing winter , which will suffer most . When we travel from south to ...
Página 74
... kind ? On the other hand , we may feel sure that any variation in the least degree injurious would be rigidly destroyed . This preservation of favourable variations and the rejection of injurious variations , I call Natural Selection ...
... kind ? On the other hand , we may feel sure that any variation in the least degree injurious would be rigidly destroyed . This preservation of favourable variations and the rejection of injurious variations , I call Natural Selection ...
Página 75
... kind would often still further increase the advantage . No country can be named in which all the native inhabitants are now so perfectly adapted to each other and to the physical conditions under which they live , that none of them ...
... kind would often still further increase the advantage . No country can be named in which all the native inhabitants are now so perfectly adapted to each other and to the physical conditions under which they live , that none of them ...
Página 77
... kind of grouse , and in keeping that colour , when once acquired , true and constant . Nor ought we to think that the occasional destruction of an animal of any particular colour would produce little effect : we should remember how ...
... kind of grouse , and in keeping that colour , when once acquired , true and constant . Nor ought we to think that the occasional destruction of an animal of any particular colour would produce little effect : we should remember how ...
Otras ediciones - Ver todas
On the Origin of Species by Means of Natural Selection: or the Preservation ... Charles Darwin Vista previa limitada - 2023 |
Términos y frases comunes
accumulated adapted affinities allied species America amount analogous ancient appear Archipelago become bees believe birds breeds cause cells characters cirripedes climate closely allied colour common parent continuous crossed crustaceans degree difficulty distinct species divergence doubt embryo endemic Europe existing exterminated extinct extremely facts favourable fertility flowers formations forms fossil Gärtner genera genus geological geological period Glacial period gradations greater number groups of species habits Hence hermaphrodites hybrids hybrids produced important individuals inhabitants inherited insects instance instincts intercrossing land larvæ less living male mammals manner Marsupials migration modification modified descendants natural selection naturalists nearly nest oceanic islands offspring organisation perfect pigeons pistil plants pollen present principle probably produced progenitor ranked reciprocal crosses remarked resemble rock-pigeon rudimentary organs seeds sexual selection Silurian slight South America sterility structure struggle successive suppose swimbladder tend theory tion trees variability variation vary whole widely