'Evolutionary transformations of fetal membranes and reproductive strategies' - International Congress of Vertebrate Morphology University of Jena, Federal Republic of Germany - July 21-26, 2001 - Preface

摘要

The Sixth International Congress of Vertebrate Morphology was held July 21-26, 2001, at the University of Jena, Federal Republic of Germany. The Congress included a symposium entitled "Evolutionary Transformations of Fetal Membranes and Reproductive Strategies." This symposium was organized by Ulrich Zeller, Andrea Mess (both of whom are at the Museum fur Naturkunde, Humboldt - Universitat, Berlin), and Daniel Blackburn (Dept. of Biology, Trinity College, Hartford, Connecticut, USA). Abstracts of the meeting were published in the June 2001 issue of the Journal of Morphology (Volume 248, Number 3). The papers presented herein are derived from the contributions to the fetal membrane symposium and some associated presentations. The main goal of our symposium was to use phylogenetic information and methods to reconstruct the evolutionary history of fetal (extraembryonic) membranes in vertebrates. Fetal membranes include the chorioallantois, amnion, and yolk sac, as well as other membranes of chondrichthyans, actinopterygians, squamates, and amphibians. These membranes perform essential roles in embryonic respiration, nutrition, and excretion, and also contribute to placental organs in viviparous vertebrates, such as various chondrichthyans, teleosts, squamates, and mammals. Phylogenetic systematics (cladistics) offers a powerful set of tools for revealing patterns of evolutionary change. As papers in this symposium volume reveal, this approach has permitted reconstructions of fetal membrane evolution in a number of lineages, sometimes with unexpected results. Symposium participants and their co-authors include some of the most active researchers in the field of comparative reproductive morphology. Their analyses have come from careful studies involving material from breeding colonies, field caught animals, and museum collections, done in scientific work extending over many years or even decades. These researchers have investigated the structure, function, and evolution of fetal membranes in eutherian mammals, marsupials, reptiles, chondrichthyans, and actinopterygians (Fig. 1). Regrettably, various factors prevented the involvement of other scientists who have contributed much to our knowledge of fetal membrane morphology and evolution. Among the vertebrate taxa considered in our symposium, amphibians and chondrichthyans were notably absent, and actinopterygians and eutherians were under-represented, given what we know of their diversity. Nevertheless; our symposium volume offers a broad overview of what is known about the evolutionary morphology of fetal membranes in several key vertebrate groups, including groups (such as squamates) that only recently have begun to receive intensive study. In addition, the contributions illustrate ways in which phylogenetic information can be used to analyze morphological and physiological diversity. Furthermore, the symposium contributions provide insight into limits of our knowledge, to stimulate efforts by other researchers, present and future. It would be difficult to think of a venue more appropriate for our symposium than the city of Jena and Friedrich-Schiller University--places steeped in intellectual tradition, that have served as a home for generations of eminent morpholo-gists. After all, it was in Jena that Johann Wolfgang Goethe, who considered himself more of a scientist than a poet, tried to account for the striking patterns of similarities and differences among vertebrate animals. The university was also where Carl Gegenbaur and Ernst Haeckel drew on ideas of Charles Darwin and Karl Ernst von Baer, in order to explain development in terms of evolution--and evolution in terms of development. Although we no longer agree with all of their explanations, these scientists were gather-ing data that serve as the basis for our concepts of evolutionary morphology--and were trying to answer questions that we continue to wonder about to this day. Half a century after Haeckel's death, biology