tailieunhanh - Homology

The concept of Homology is fundamental to the field of comparative biology. In 1843, Richard Owen defined homology as "the same organ in different animals under every variety of form and function". Homology is evaluated strictly in an evolutionary context. That is, organs in two species are homologous only if the same structure was present in their last common ancestor. Organs as disparate as a bat's wing, a seal's flipper, a cat's limb and a human arm have a common underlying anatomy which was present in their last common ancestor and so therefore are homologous as forelimbs | HOMOLOGY DR. SAUNDERS MAC LANE MAX MASON DISTINGUISHED SERVICE PROFESSOR OF MATHEMATICS AT THE UNIVERSITY OF CHICAGO WITH 7 FIGURES SPRINGER-VERLAG BERLIN GOTTINGEN HEIDELBERG 1963 Geschăítsíũhrende Herausgeber Prof. Dr. B. Eckmann Eidgenôssische Technische Hochschule Zorich Prof. Dr. B. L. VAN DER Waerden Mathematisches Institut der Universităt Zurich Alỉe Rechte insbesondere das der ưbersetaung in íretnde Sprachen vorbehalten Ohne ausdruckliche Genehmigung des Verlages 1st es auch nicht gestattet dieses Buch Oder Teile daraus auf photomechanischem Wege Photokopie Mikrokopie Oder auf andere Art ZU vervielíăltigen By Springer-Verlag OHG. Berlin Gottingen Heidelberg 1963 Library of Congress Catalog Card Number 63-12929 Printed in Germany 4 Druck der Uníversitătsdruckerei H. startz AG. Wiirzburg TO .