The Origin of Species by Means of Natural Selection: Or, The Preservation of Favored Races in the Struggle for Life, Volumen2AMS Press, 1972 |
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Página 40
... greater than in hybrids . This greater variability in mongrels than in hybrids does not seem at all surprising . For the parents of mongrels are varieties , and mostly domestic varieties ( very few experiments having been tried on ...
... greater than in hybrids . This greater variability in mongrels than in hybrids does not seem at all surprising . For the parents of mongrels are varieties , and mostly domestic varieties ( very few experiments having been tried on ...
Página 91
... greater or less degree , thus causing a greater or less amount of permanent modification , will depend on many complex contingencies - on the variations being of a beneficial nature , on the freedom of intercrossing , on the slowly ...
... greater or less degree , thus causing a greater or less amount of permanent modification , will depend on many complex contingencies - on the variations being of a beneficial nature , on the freedom of intercrossing , on the slowly ...
Página 262
... greater size of rudimentary organs in the embryo relatively to the adjoining parts , and their lesser relative size in the adult . If , for instance , the digit of an adult animal was used less and less during many generations , owing ...
... greater size of rudimentary organs in the embryo relatively to the adjoining parts , and their lesser relative size in the adult . If , for instance , the digit of an adult animal was used less and less during many generations , owing ...
Contenido
CONTENTS OF VOL | 1 |
CHAPTER X | 48 |
CHAPTER XII | 129 |
Derechos de autor | |
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The Origin of Species by Means of Natural Selection: Or, The Preservation of ... Charles Darwin Vista de fragmentos - 1962 |
The Origin of Species by Means of Natural Selection: Or, The Preservation of ... Charles Darwin Vista de fragmentos - 1963 |
Términos y frases comunes
accumulated adapted admit adult affinity allied species ancient animals appear Archipelago arctic areas become beds believe birds breeds Cambrian changes characters classification climate closely allied continent crustaceans degree deposited difficulty distant distinct species domestic doubt embryo Europe existing extinct fact faunas fertilised fertility flowers formations formerly forms fossil fresh-water Fritz Müller Gärtner genera genus geological period geological record Glacial period groups of species habits hybrids hybrids produced important individuals inhabitants inherited insects instance intermediate intervals land larvæ less living mammals manner marine Marsupials migration modified descendants mongrels mountains natural selection naturalists nearly occur oceanic islands offspring organisation parent parent-form peculiar perfect pistil plants pollen present probably produced quadrupeds reciprocal crosses regions remains remarked reproductive resemblance rocks rudimentary organs seeds Silurian slight South America species belonging stage stamens sterility structure successive suppose terrestrial tertiary tion variations varieties whilst widely different wings