On the Origin of Species by Means of Natural Selection: Or the Preservation of Favoured Races in the Struggle for Life |
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Page 88
... intercrossing with the other individuals of the same species on the confines of each . And in this case the effects of intercrossing can hardly be counter- balanced by natural selection always tending to modify all the individuals in ...
... intercrossing with the other individuals of the same species on the confines of each . And in this case the effects of intercrossing can hardly be counter- balanced by natural selection always tending to modify all the individuals in ...
Page 89
... Intercrossing plays a very important part in nature in keeping the individuals of the same species , or of the ... intercrosses take place with all animals and with all plants . Even if these take place only at long intervals , I am con ...
... Intercrossing plays a very important part in nature in keeping the individuals of the same species , or of the ... intercrosses take place with all animals and with all plants . Even if these take place only at long intervals , I am con ...
Page 302
... intercross , I believe that during the slow process of modification the individuals of the species will have been kept nearly uniform by intercrossing , so that many individuals will have gone on simultaneously changing , and the whole ...
... intercross , I believe that during the slow process of modification the individuals of the species will have been kept nearly uniform by intercrossing , so that many individuals will have gone on simultaneously changing , and the whole ...
Contents
INTRODUCTION | 1 |
STRUGGLE FOR EXISTENCE | 52 |
NATURAL SELECTION | 69 |
Copyright | |
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Common terms and phrases
accumulated adapted affinities allied species 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 distant distinct species divergence doubt embryo Europe existing exterminated extinct extremely facts favourable fertility flowers formation forms fossil Gärtner genera genus geological geological period Glacial period gradations greater number groups of species habits Hence hermaphrodites hybrids hybrids produced important increase in number individuals inhabitants inherited insects instance instincts intercrossing land larvæ less living male mammals manner migration modification modified descendants natural selection naturalists nearly nest occasional oceanic islands offspring Origin of Species perfect pigeons plants pollen present principle probably produced progenitor ranked reciprocal crosses remarked resemblance seeds sexual selection Silurian slight sometimes South America sterility structure struggle successive supposed swimbladder tend theory tion trees variability variation vary whole widely