Darwin and after Darwin
Format: Paperback
ISBN13: 9780217814195
Paperback|9780217814195
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Purchase of this book includes free trial access to www.million-books.com where you can read more than a million books for free. This is an OCR edition with typos. Excerpt from book: CHAPTER IV. Evidences Of Physiological Selection. I WILL now give an outline sketch of the evidences in favour of the theory which has been set forth in the preceding chapter, stating first what is the nature of the verification which it requires. The theory is deduced from a highly general association between distinctive specific characters of any kind and a relatively constant specific character of a particular kind ? namely, sexual exclusiveness. For it is from this highly general association that the theory infers that this relatively constant specific character has been at least one of the needful conditions to the development of the other specific characters with which it is found associated. Hence the necessary verification must begin by showing the strength of the theory on these merely deductive, or antecedent, grounds. It may then proceed to show how far the facts of organic nature corroborate the theory in other and independent ways. t First, let it be carefully observed that here we have to do only with the fad of selective fertility, and with its consequences as supposed by the theory: we havenothing to do either with its causes or its degrees. Not with its causes, because in this respect the theory of physiological selection is in just the same position as that of natural selection: it is enough for both if the needful variations are provided, without its being incumbent on either to explain the causes which produce them. Not with its degrees, because, in the first place, it can only be those degrees of variation which in particular cases are supposed adequate to induce specific divergence, that fall within the scope of the theory; and because, in the second place, degrees which are adequate only to induce?or to assist in inducing varietal divergence, must ...
| ISBN-13 | 9780217814195 |
|---|---|
| ISBN-10 | 0217814190 |
| Weight | 0.36 Pounds |
| Dimensions | 9.00 x 6.00 x 0.24 In |
| List Price | $19.99 |
| Format | Paperback |
|---|---|
| Pages | 102 pages |
| Publisher | |
| Published On | 2009-08-01 |
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