Organic Evolution : Outstanding Difficulties and Possible Explanations (Paperback)

Preface; 1. The selection of infrequent mutations and the inheritance of acquired characters could not alone account for evolution; 2. To admit the selection of small and frequent mutations amongst the explanations of evolution demands the solution of several unsolved problems; 3. The existence of a system of mutations due to imperfect segregation is suggested as one of the possible explanations; 4. The problems to be solved include the appearance of new forms and the bifurcation of species; 5. Infertility between species and facts connected with pure lines have also to be explained; 6. In experiments designed to test this hypothesis natural conditions should be imitated as far as possible.