It is now accepted that the first cells derived from simpler "objects", and that their descendants became more and more complicated and ordered until their evolutionary transformation into modern cells, namely, cells endowed with the same basic structures and mechanisms as those existing today. Although the appearance of the first modern cells goes back at least two billion years, many scholars believe that it occurred almost four billion years ago. In that case, the Earth's formation, which took place quite quickly about 4. 6 billion years ago, is in close proximity to the originoflife. There is disagreement not only about the moment ofappearance ofmodern cells, but also as to their early evolution. Ideas on the first steps in cellular evolution vary considerably, and our present knowledge is so limited as to be little more than vacuous. Why discuss it then? Precisely because it is an empty space that needs to be filled! Does it make sense only to discuss things which are well-known and well documented? Is this the best way to interpret that spirit of exploration of the unknown which is at the very heartofscientific endeavor? The idea that it is idle to venture into fields which are poorly documented has been long supported, even in cases similar to those dealt with here, for example, the evolutionary phases which took place before the first cell.

Origin and Early Evolution of Life draws on evidence from molecular genetics, the structure and function of extant organisms, and geology. It covers the period from about 4 billion years ago, when life is thought to have originated, to about 600 million years ago when multicellular organisms first arose. There are significant gaps in our understanding of the earliest evolution of life forms, but an insight into the topic leads to a more profound understanding of life itself. Particular emphasis is placed on the fact that although life arose very soon after the origin of the Earth, it was represented only by simple microbial life forms for approximately 85% of this time. Increase in complexity beyond the microbial level took place only very late in the history of life.

Starburst regions in nearby and distant galaxies have a profound impact on our understanding of the early universe. This new, substantially updated and extended edition of Norbert Schulz’s unique book "From Dust to Stars" describes complex physical processes involved in the creation and early evolution of stars. It illustrates how these processes reveal themselves from radio wavelengths to high energy X-rays and gamma–rays, with special reference towards high energy signatures. Several sections devoted to key analysis techniques demonstrate how modern research in this field is pursued and new chapters are introduced on massive star formation, proto-planetary disks and observations of young exoplanets. Recent advances and contemporary research on the theory of star formation are explained, as are new observations, specifically from the three great observatories of the Spitzer Space Telescope, the Hubble Space Telescope and the Chandra X-Ray Observatory which all now operate at the same time and make high resolution space based observing in its prime. As indicated by the new title two new chapters have been included on proto-planetary disks and young exoplanets. Many more colour images illustrate attractive old and new topics that have evolved in recent years. The author gives updates in theory, fragmentation, dust, and circumstellar disks and emphasizes and strengthens the targeting of graduate students and young researchers, focusing more on computational approaches in this edition.

Since the last International Astronomical Union Symposium that dealt with matters cosmological, there have been dramatic advances, both on the observational and theoretical fronts. Modern high-efficiency detectors have made possible extensive magnitude-limited redshift surveys, which have permitted observational cosmologists to construct three-dimensional maps of large regions of space. What seems to emerge is a distribution of matter in extensive, flat, but probably filamentary, and possibly interconnected, superclusters, serving as interstices between vast voids in space. Meanwhile, theoretical ideas that were highly speculative a few years ago have begun to be taken seriously as possibly describing conditions in the very early universe. And brand new ideas, such as that of the inflationary universe, hold promise of solving outstanding observational, theoretical, and philosophical problems in cosmology. A new look at grand unified theories and concepts of supersymmetry have brought observational and theoretical cosmologists to a common meeting ground with modern particle physicists.

Several years ago, we realized that the most prominent ideas that had been ex pressed about the origin and early evolution of the Metazoa seemed to have been developed chiefly by zoologists using evidence from modern species without reference to the fossil record. Paleontologists had, in fact, put forth their own ideas but the zoological and the paleontological evidence were about the problem, seldom considered together, especially by zoologists. We believed that the paleon tological documentation of the first Metazoa was too scattered, too obscure to Western readers, and much of it too recent to have been readily available to our colleagues in zoology. Whether or not that was entirely true, we thought that a single volume reviewing the fossil record of the earliest Metazoa would be useful to many in both paleontology and zoology, especially since so much new informa tion has been developed in the last few years. Some of this information has been summarized in general articles recently, but an overview of most of the field does not exist. We therefore organized this book in five parts so that the evidence could be placed in perspective and summarized and inferences made from it. Part I intro duces the previous hypotheses that have been proposed for the origin and early radiation of Metazoa. Part II consists of two summary chapters that set the sedi mentological, geochemical, and biological background to the known radiations of Metazoa.

This work examines the cognitive capacity of great apes in order to better understand early man and the importance of memory in the evolutionary process. It synthesizes research from comparative cognition, neuroscience, primatology as well as lithic archaeology, reviewing findings on the cognitive ability of great apes to recognize the physical properties of an object and then determine the most effective way in which to manipulate it as a tool to achieve a specific goal. The authors argue that apes (Hominoidea) lack the human cognitive ability of imagining how to blend reality, which requires drawing on memory in order to envisage alternative future situations, and thereby modifying behavior determined by procedural memory. This book reviews neuroscientific findings on short-term working memory, long-term procedural memory, prospective memory, and imaginative forward thinking in relation to manual behavior. Since the manipulation of objects by Hominoidea in the wild (particularly in order to obtain food) is regarded as underlying the evolution of behavior in early Hominids, contrasts are highlighted between the former and the latter, especially the cognitive implications of ancient stone-tool preparation.