This interdisciplinary book consists of the proceedings of the Alexander Ivanovich Oparin lOOth Anniversary Conference, The Third Trieste Conference on Chemical Evolution, which took place at the International Centre for Theoretical Physics from 29 August till 2 September, 1994. A general overview of Oparin's life and work is followed by a review of Alfonso Herera, another pioneer in the studies of the origin of life. The subject matter is organized in ten sections corresponding to various aspects of our current understanding of the subject that was initiated by Oparin. These subjects were covered by fifty three speakers. There were sixty seven participants from a wide geographical distribution, twenty seven countries were represented. We have included the invited lecture of Professor Igor Kulaev, who was unable to be present at the conference for reasons beyond his control. The conference was generously supported by the International Centre for Theoretical Physics, the Commission of the European Communities, the International Centre for Genetic Engineering and Biotechnology, the International Centre for Science and High Technology, and UNESCO. Cyril Ponnamperuma, University of Maryland, U.S.A. Julian Chela-Flores, ICTP, Italy, and IDEA, Venezuela. xi FOREWORD As this volume was going to press we learnt of the untimely death of Cyril Ponnamperuma who died of cardiac arrest on December 20, 1994.