Fascinated by the diversity of living organisms, humans have always been curious about its origin. Darwin was the first to provide the scholary and persuasive thesis for gradual evolution and speciation under natural selection. Although we now have much information on evolution, we still don't understand it in detail. Many questions still remain open due to the complexity and multiplicity of interacting factors. Several approaches mainly arising from population ecology and genetics are presented in this book in order to help understand genetic variation and evolution.

This volume contains the papers presented at a symposium on popula tion biology sponsored by the Deutsche Forschungsgemeinschaft. It was . held at the guest house of the University of Ttibingen at Oberjoch on May 15-19, 1983. Prior to this conference a small group of European biologists had met in Berlin (June 1981) and Pavia (September 1982) to discuss re search problems on the borderline between population genetics and evolutionary ecology. From the contributions and discussions at these meetings it became evident that the unification of approaches to evolutionary problems in population genetics and evolutionary ecology has not yet been suc cessful and requires further efforts. It was the consensus that a larger symposium with international participation would be helpful to con front and discuss the different approaches to population biology in order to assess "where we are now" and "where we should be going. " As a result an organizational committee was formed (F. Christiansen, S. Jayakar, V. Loeschcke, W. Scharloo, and K. W6hrmann) to iden tify topics that seemed, at least to them, to be fruitful in tackling problems in population biology. Consequently, a number of colleagues were asked to participate in the meeting. We have divided this book into chapters corresponding to the eight topics chosen. The volume begins with the relation between genotype and phenotype and is followed by a chapter on quantitative genetics and selection in natural populations."

In 1992, a group of scientists including molecular biologists, microbiologists, population biolo gists, ecologists, human geneticists, moral philosophers and others met discussing the state of affairs regarding the deliberate or unintentional release of genetically modified organisms. The proceedings of this meeting were subsequently published by Birkhauser Verlag as Transgenic Organisms: Risk Assessment of Deliberate Release (K. Wohrmann and J. Tomiuk). Since then we have gained many new insights that are also worthy of discussion. And although other equally important scientific views on the release of genetically modified organisms exist, we have mainly concentrated on aspects of population biology and evolution. The results of a second meeting in 1995 are summarized here. We are grateful to colleagues and friends for their help in the translation, correction and review of the authors' contributions. We especially want to thank Jutta Bachmann, Donna Devine, Diana von Finck, Friedrich Laplace, Volker Loeschcke, Rolf Lorenz, Dave Parker and Trevor Petney. A grant (BMFT N' 0311035) from the Ministerium fUr Forschung und Technologie der Bundesrepublik Deutschland again made possible the continuation of this cooperative endeavour."

In 1992, a group of scientists including molecular biologists, microbiologists, population biolo gists, ecologists, human geneticists, moral philosophers and others met discussing the state of affairs regarding the deliberate or unintentional release of genetically modified organisms. The proceedings of this meeting were subsequently published by Birkhauser Verlag as Transgenic Organisms: Risk Assessment of Deliberate Release (K. Wohrmann and J. Tomiuk). Since then we have gained many new insights that are also worthy of discussion. And although other equally important scientific views on the release of genetically modified organisms exist, we have mainly concentrated on aspects of population biology and evolution. The results of a second meeting in 1995 are summarized here. We are grateful to colleagues and friends for their help in the translation, correction and review of the authors' contributions. We especially want to thank Jutta Bachmann, Donna Devine, Diana von Finck, Friedrich Laplace, Volker Loeschcke, Rolf Lorenz, Dave Parker and Trevor Petney. A grant (BMFT N' 0311035) from the Ministerium fUr Forschung und Technologie der Bundesrepublik Deutschland again made possible the continuation of this cooperative endeavour."