| Glyn Lloyd-Hughes - 2005 - 412 páginas
...changed conditions of life, it is at least possible that slightly changed instincts might be profitable; and if it can be shown that instincts do vary ever...no difficulty in natural selection preserving and accumulating their variations. But, as with corporeal structures, we ought to find in nature, not the... | |
| Charles Darwin - 2006 - 608 páginas
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| Charles Darwin - 2007 - 556 páginas
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| Sir Norman Lockyer - 1882 - 720 páginas
...important as corporeal structures for the welfare of each species, under its present conditions of life. Under changed conditions of life, it is at least possible...accumulating variations of instinct to any extent that was profitable. It is thus, I believe, that all the most complex and wonderful instincts have originated."... | |
| 1898 - 476 páginas
...Bulletin No. 2. Scientific Series No 1. 1898. IN discussing the problem of Instinct, Darwin wrote, "If it can be shown that instincts do vary ever so...accumulating variations of instinct to any extent that was profitable." This sentence might well serve as the text for the charming book before us, and seems... | |
| R. W. Sheldon - 2004
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| Raymond Pearl - 1928 - 656 páginas
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