Unlike some other reproductions of classic texts (1) We have not used OCR(Optical Character Recognition), as this leads to bad quality books with introduced typos. (2) In books where there are images such as portraits, maps, sketches etc We have endeavoured to keep the quality of these images, so they represent accurately the original artefact. Although occasionally there may be certain imperfections with these old texts, we feel they deserve to be made available for future generations to enjoy.

This volume is based on the Field Museum of Natural History Spring System atics Symposium held in Chicago on May 11, 1991. The financial support of Ray and Jean Auel and of the Field Museum is gratefully acknowledged. When we teach or write, we present only those elements that support our arguments. We avoid all weak points of our debate and all the uncer tainties of our models. Thus, we offer hypotheses as facts. Multiauthored books like ours, which simultaneously advocate and question diverse views, avoid the pitfalls and lessen the impact of indoctrination. In this volume we analyze the anthropological and biological disagreements and the positions taken on the origins of modern humans, point out difficultieswith the inter pretations, and suggest that the concept of the human origin can be explained only when we first attempt to define Homo sapiens sapiens. One of the major controversies in physical anthropology concerns the geographic origin of anatomically modern humans. It is undisputed, due to the extensive research of the Leakeys and their colleagues, that the family Hominidae originated in Africa, but the geographic origin of Homo sapiens sapiens is less concretely accepted. Two schools of thought existon this topic."

Problematic fossils--those groups of organisms that do not fit conveniently into any existing phylum--play a pivotal role in the reconstruction of the history of life, being in effect "early experiments." This lavishly illustrated volume provides careful analyses and descriptions--in anatomical, functional, and developmental terms--of most of the major problematic fossil taxa. Sixteen original papers, written by internationally recognized scholars, discuss the features that make these taxa problematic and that provide clues to their phylogenetic relationships. Since Precambrian groups have been well covered in the existing literature, Hoffman and Nitecki focus on Paleozoic, and especially Early Paleozoic organisms, although Precambrian biota are also discussed.

Receptaculitids are extinct high-level fossils that provide a window into the history of life. After the discovery and analysis of a deposit of phosphatized receptaculitids on the Baltic Sea island of Oland, the authors conclude that receptaculitids possess an attribute not found in any other group of organisms, living or fossil."

The successful early adaptations of man involve a complex interplay of biological and cultural factors. There is a rapidly growing number of paleontologists and paleoanthropologists who are concerned with hominid foraging and the evolution of hunting. New techniques of paleoanthropology and taphonomy, and new information on human remains are added to the traditional approaches to the study of past human hunting and other foraging behavior. There is also a resurgence of interest in the early peopling of the New World. The present book is the result of the Ninth Annual Spring Systematics 10, 1986, in the Symposium, on the Evolution of Human Hunting, held on May Field Museum of Natural History in Chicago. We are grateful to the NSF (grant no. BNS 8519960) for partial financial support in arranging the symposium. In preparation of this volume we have received assistance from many people, particularly the reviewers of individual chapters; it is impossible to name them all. We must however single out Drs. Richard G. Klein and Glen H. Cole for their encouragement at various stages of preparation of the symposium and this volume, and for being a help to the anthropological knowledge. Zbigniew Jastrzebski assisted with the figures and Paul K. Johnson diligently typed the camera-ready copy, and patiently coordinated the endless book-making chores.

This symposium volume highlights current research in the general field of animal behaviour. The contributors have focused on a series of studies confronting wide-ranging issues: sexual selection, mate choice; differential parental investment, apparent altruism and cooperative behaviour, and the relevance of phylogenetic constraints and historical information. The volume will appeal to evolutionary biologists, behavioural ecologists, palaeontologists, and systematic zoologists, as well as graduate students in these areas.

This volume is based on the Field Museum of Natural History Spring System atics Symposium held in Chicago on May 11, 1991. The financial support of Ray and Jean Auel and of the Field Museum is gratefully acknowledged. When we teach or write, we present only those elements that support our arguments. We avoid all weak points of our debate and all the uncer tainties of our models. Thus, we offer hypotheses as facts. Multiauthored books like ours, which simultaneously advocate and question diverse views, avoid the pitfalls and lessen the impact of indoctrination. In this volume we analyze the anthropological and biological disagreements and the positions taken on the origins of modern humans, point out difficultieswith the inter pretations, and suggest that the concept of the human origin can be explained only when we first attempt to define Homo sapiens sapiens. One of the major controversies in physical anthropology concerns the geographic origin of anatomically modern humans. It is undisputed, due to the extensive research of the Leakeys and their colleagues, that the family Hominidae originated in Africa, but the geographic origin of Homo sapiens sapiens is less concretely accepted. Two schools of thought existon this topic.

Receptaculitids are extinct high-level fossils that provide a window into the history of life. After the discovery and analysis of a deposit of phosphatized receptaculitids on the Baltic Sea island of Oland, the authors conclude that receptaculitids possess an attribute not found in any other group of organisms, living or fossil.

Neutral models are constructed to help scientists understand complex patterns of form, structure, or behavior that may not be observed directly. In this unique volume, eight distinguished scientists present a comprehensive study of the use of neutral models in testing biological theories. They describe the principles of model testing and explore how they are applied to research in molecular biology, genetics, ecology, evolution, and paleontology. In addition to the editors, the contributors include Stephen Stigler, David Raup, Paul Harvey, L.B. Slobodkin, Stuart Kauffman, William Wimsatt, and James Crow.

This is a reproduction of a book published before 1923. This book may have occasional imperfections such as missing or blurred pages, poor pictures, errant marks, etc. that were either part of the original artifact, or were introduced by the scanning process. We believe this work is culturally important, and despite the imperfections, have elected to bring it back into print as part of our continuing commitment to the preservation of printed works worldwide. We appreciate your understanding of the imperfections in the preservation process, and hope you enjoy this valuable book.

Evolutionary innovations--the bony skeleton of vertebrates, avian flight, or the insect pollination system of angiosperms, for example--have in recent years become the focus of much fertile new research in evolutionary biology. Innovations may hold the keys to understanding why whole new groups of organisms evolve or, conversely, why groups of organisms become extinct. This volume brings together contributors from the fields of morphology, genetics, embryology, physiology, and paleontology to present research on evolutionary innovations and to suggest directions for further work.
The topics covered include the plurality of evolutionary innovations, patterns and processes at different hierarchical levels, evolutionary genetics of adaptations, heterochrony and other mechanisms of radical evolutionary change in early development, developmental mechanisms at the origin of morphological novelty, the evolution of morphological variation patterns, functional design and its punctuated products, plausibility and testability in assessing the consequences of evolutionary innovations, paradigms and pitfalls of studying physiological evolution, polyphyletic constructional breakthroughs in fossil and extant species, ecology of evolutionary innovations in the fossil record.