PRESENT PROBLEMS IN EVOLUTION AND HEREDITY CLASSIC REPRINT

ISBN: 9781397324016 Géneros: PSAJ Sinópsis: Excerpt from Present Problems in Evolution and HeredityThe reversional tendency is hereditary There are many cases both of reversions as in the teeth and indefinite variations being hereditary that is reappearing in several generations or skipping a generation and recurring in the secondSummary 13mm are clearly marked out several regions in the human body in which evolution is relatively most rapid such as the lower portion of the chest the upper cervicals the shoulder girdle in its rela tion to the trunk the lower portion of the arm and hand the outer portion of the foot We notice that these regions especially are centers of adaptation to new habits of life in which new organs and new rela tions of parts are being acquired and old organs abandonedWe observe also that all parts of the body are not equally variable but these centers of evolution are also the chief centers of variability The variations here are not exclusively but mainly of one kind they rise from the constant struggle between adaptation and the force of heredity Here is a muscle like the extensor indicis attempting to give up an old function and establish a new one it maintains its new func tion for several generations and then goes back without any warning to a function which it had thousands of years ago Thus the force of reversion strikes us as a universal factorAbout the PublisherForgotten Books publishes hundreds of thousands of rare and classic books Find more at wwwforgottenbookscomThis book is a reproduction of an important historical work Forgotten Books uses stateoftheart technology to digitally reconstruct the work preserving the original format whilst repairing imperfections present in the aged copy In rare cases an imperfection in the original such as a blemish or missing page may be replicated in our edition We do however repair the vast majority of imperfections successfully any imperfections that remain are intentionally le