Problems of Genetics
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| Problems of Genetics |
In the year 1883, a legacy of about eighty-five thousand dollars was left to the President and Fellows of Yale College in the city of New Haven, to be held in trust, as a gift from her children, in memory of their beloved and honoured mother, Mrs Hepsa Ely Silliman.
On this foundation, Yale College was requested and directed to establish an annual course of lectures designed to illustrate the presence and providence, the wisdom and goodness of God, as manifested in the natural and moral world. These were to be designated as the Mrs Hepsa Ely Silliman Memorial Lectures.
It was the belief of the testator that any orderly presentation of the facts of nature or history contributed to the end of this foundation more effectively than any attempt to emphasize the elements of doctrine or of creed; and he, therefore, provided that lectures on dogmatic or polemical theology should be excluded from the scope of this foundation and that the subjects should be selected rather from the domains of natural science and history, giving special prominence to astronomy, chemistry, geology, and anatomy.
It was further directed that each annual course should be made the basis of a volume to form part of a series constituting a memorial to Mrs Silliman. The memorial fund came into the possession of the Corporation of Yale University in the year 1901, and the present volume constitutes the fifth of the series of memorial lectures.
This book gives the substance of a series of lectures delivered at Yale University, where I had the privilege of holding the office of Silliman Lecturer in 1907. T
he delay in publication was brought about by a variety of causes. Inasmuch as the purpose of the lectures is to discuss some of the wider problems of biology in the light of knowledge acquired by Mendelian methods of analysis, it was essential that a fairly full account of the conclusions established by them should first be undertaken and I, therefore, postponed the present work till a book on Mendel's Principles had been completed. On attempting a more general discussion of the bearing of the phenomena on the theory of Evolution, I found myself continually hindered by the consciousness that such treatment is premature, and by doubt, whether it was not better than the debate should for the present stand indefinitely adjourned.
That species has come into existence by an evolutionary process no one seriously doubts, but few who are familiar with the facts that genetic research has revealed are now inclined to speculate as to the manner by which the process has been accomplished.
Our knowledge of the nature and properties of living things is far too meagre to justify any such attempts. Suggestions of course can be made: though however, these ideas may have a stimulating value in the lecture room, they look weak and thin when set out in print. The work which may one day give them a body has yet to be done.
The development of negations is always an ungrateful task apt to be postponed for the positive business of experiment. Such work is happily now going forward in most of the centres of scientific life. Of many of the subjects here treated we already know more than we did in 1907. The delay in production has made it possible to incorporate these new contributions.
The book makes no pretence at being a treatise and the number of illustrative cases has been kept within a moderate compass. A good many of the examples have been chosen from American natural history, as being appropriate to a book intended primarily for American readers.
The facts are largely given on the authority of others, and I wish to express my gratitude for the abundant assistance received from American colleagues, especially from the staff of the American Museum in New York, and of the Boston Museum of Natural History.
In connexion with the particular subjects, personal acknowledgements are made. Dr F. M. Chapman was so good as to supervise the preparation of the coloured Plate of Colaptes, and to authorize the loan of the Plate representing the various forms of Helminthophila, which is taken from his North American Warblers. I am under obligation to Messrs. Macmillan & Co., for permission to reproduce several figures from Materials for the Study of Variation, illustrating subjects which I wished to treat in new associations, and to M. Leduc for leave to use Fig. 9.
In conclusion, I thank my friends at Yale for the high honour they did me by their invitation to contribute to the series of Silliman Lectures, and for much kindness received during a delightful sojourn in that genial home of learning.
Contents:
I. Introductory. The Problem of Species and Variety i
II. Meristic Phenomena 31
III. Segmentation, Organic and Mechanical 60
IV. The Classification of Variation and the Nature
of Substantive Variation 83
Note to Chapter IV 94
V. The Mutation Theory 97
Note to Chapter V 116
VI. Variation and Locality 118
VII. Local Differentiation — continued. Overlapping Forms 146
VIII. Locally Differentiated Forms — continued. Climatic Varieties 164
IX. The Effects of Changed Conditions 187
X. The Effects of Changed Conditions — continued.
The Causes of Genetic Variation 212
XI. The Sterility of Hybrids. Concluding Re-
marks 233
marks 233
Appendix to Chapter X 250
Index 251
Author: William Bateson
Publication Date: 1913
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