One of the major questions in the evolution of animals is the transition from unicellular to multicellular organization, which resulted in the emergence of Metazoa through a hypothetical Urmetazoa. The Comparative Embryology of Sponges contains abundant original and literary data on comparative embryology and morphology of the Porifera (Sponges), a group of 'lower Metazoa'. On the basis of this material, original typization of the development of Sponges is given and the problems concerning origin and evolution of Porifera and their ontogenesis are discussed. A morphogenetic interpretation of the body plan development during embryogenesis, metamorphosis and asexual reproduction in Sponges is proposed. Special attention is given to the analysis of characteristic features of the ontogenesis in Porifera. The book pursues three primary goals: 1) generalization of all existing information on individual development of sponges, its classification and a statement according to taxonomical structure of Porifera; 2) revealing of heterogeneity of morphogenesis and peculiarities of ontogeneses in various clades of Porifera, and also their correlations with the organization, both adult sponges, and their larvae; 3) revealing homology of morphogeneses in both Porifera and Eumetazoa, testifying to the general evolutionary roots of multicellular animals, and peculiar features of sponges' morphogeneses and ontogenesis. This book will be of interest to embryologists, zoologists, morphologists and researchers in evolutionary biology.

Discover a new outlook on the process of life—and improve your health as a result In Intended Evolution, authors Dongxun and Bob Zhang introduce a different perspective on the theory of evolution: Life is not only selected by nature but intentionally interacts with it, learning how to better its future. They explain that applying this idea to generally accepted principles of biology can have startling results in your ability to affect your own health—and even your evolution. According to the theory of intended evolution, organisms gather information through sensory experience and use that knowledge to effect change in themselves and their environments. The authors propose that organisms use this saved information to make choices projected to enhance their survival. It is through experience, choices, and action, within a given environment, that life changes itself from moment to moment and determines what changes are needed for future generations. Because of humans’ unique ability to understand how our own evolution functions, we can effect changes within ourselves to influence and enhance our health and fitness, even to lengthen our lifespan.

In the 17th century, Descartes put forth the metaphor of the machine to explain the functioning of living beings. In the 18th century, La Mettrie extended the metaphor to man. The clock was then used as the paradigm of the machine. In the 20th century, this metaphor still held but the clock was replaced by a computer. Nowadays, the organism is viewed as a robot obeying signals emanating from a computer program controlled by genetic information. This book shows that such a conception leads to contradictions not only in the theory of biology but also in its experimental research program, thereby impeding its development. The analysis of this problem is based on the most recent experimental data obtained in molecular biology as well as the history and philosophy of biology. It shows that the machine theory did not succeed in breaking with Aristotle's finalism. The book presents a new approach to biological systems based on cellular Darwinism. Genes are ruled by probabilistic mechanisms allowing cells to differentiate stochastically. Embryo development is not governed by a determinist genetic program but by natural selection occurring among cell populations inside the organism. This theory has considerable philosophical consequences. Man may be a machine but he is a random one.

This reference work breaks new ground as an electronic resource. Utterly comprehensive, it serves as a repository of knowledge in the field as well as a frequently updated conduit of new material long before it finds its way into standard textbooks.

Man develops during phylogenesis and ontogenesis as an active creature and his most striking external manifestations include physical activity. From this ensue efforts to investigate the human organism with regard to its functional diagnosis mainly during activity, in relation to the level of that physical activity. The amount and qualitative aspect of physical activity is subject to some laws associated with the developmental stage, type of higher nervous activity, health, nutritional status, external environment inc!. social position, profession, hobbies, etc.; thus it is also one of the important ecological factors. During the period before the onset of technical civilization physical fitness and performance were essential prerequisites for survival and successful existence. At present and from the aspect of the perspective development of our civilization the importance of physical fitness is pushed into the background; nevertheless adequate physical activity level is even today an important prerequisite for normal function of the organism as a whole.