Abstract
IN the series of articles by Dr. Ruggles Gates appearing under the above title in a New Phytologist Reprint (No. 12), published by Messrs. Wheldon and Wesley, Ltd., we have the most recent attempt to present a reasoned and comprehensive statement of the problem of evolution. .As the author tells us, his aim has been to show that though germinal (by which apparently we may understand chromosomal) changes are of importance in the evolutionary process, they can-,not be considered as all-sufficing; that only from the Neo-Lamarckian point of view is it possible to explain a large class of organic phenomena. From this point he sets out to show how the Darwinian odoctrine and Mendelian conceptions in combination may furnish us with a solution. To this end, how-oever, it scarcely seems necessary to maintain, as the -author is at pains to reiterate, that in the application oof Mendelian principles we are merely putting' into use a refinement of the theory of natural selection. Nor does any point appear to be gained by this insistence on accord, since, by the author' own showing, the underlying difference between Darwinism and Mendelism—the difference, namely, between the idea oof continuity and discontinuity—is profound enough to have divided biologists into two opposite camps. oOne feels that what is common ground might more easily be made apparent if an attempt were made to define more strictly, or else to abandon, terms which are used to cover an ever-increasing complex of ideas. It will be obvious, for example, that a fresh analysis oof evolutionary processes should be couched in terms which clearly differentiate the causes (= true factors) to which variation is presumably due from the mechanism by which variations, once having appeared, are perpetuated, and from conditions which permit or limit the occurrence of variation. That the author evidently has in mind the necessity for precision in this connection appears from the fact that he is careful to point out that isolation due to geographical barriers must be regarded as a condition, and not as a factor, yet he fails to draw this distinction when dealing with natural selection.
Article PDF
Rights and permissions
About this article
Cite this article
Mutations and Evolution. Nature 107, 636–637 (1921). https://doi.org/10.1038/107636a0
Issue Date:
DOI: https://doi.org/10.1038/107636a0