The genetic code appeared on Earth with the first cells. The codes of cultural evolution arrived almost four billion years later. These are the only codes that are recognized by modern biology. In this book, however, Marcello Barbieri explains that there are many more organic codes in nature, and their appearance not only took place throughout the history of life but marked the major steps of that history. A code establishes a correspondence between two independent 'worlds', and the codemaker is (...) a third party between those 'worlds'. Therefore the cell can be thought of as a trinity of genotype, phenotype and ribotype. The ancestral ribotypes were the agents which gave rise to the first cells. The book goes on to explain how organic codes and organic memories can be used to shed new light on the problems encountered in cell signalling, epigenesis, embryonic development, and the evolution of language. (shrink)

Familiarity with Charles Darwin's treatise on evolution is essential to every well-educated individual. One of the most important books ever published--and a continuing source of controversy, a century and a half later--this classic of science is reproduced in a facsimile of the critically acclaimed first edition.

This collection broadens the scientific discussion of modularity by bringing together experts from a variety of disciplines, including artificial life, ...

There are currently three major theories on the origin and evolution of the genetic code: the stereochemical theory, the coevolution theory, and the error-minimization theory. The first two assume that the genetic code originated respectively from chemical affinities and from metabolic relationships between codons and amino acids. The error-minimization theory maintains that in primitive systems the apparatus of protein synthesis was extremely prone to errors, and postulates that the genetic code evolved in order to minimize the deleterious effects of the (...) translation errors. This article describes a fourth theory which starts from the hypothesis that the ancestral genetic code was ambiguous and proposes that its evolution took place with a mechanism that systematically reduced its ambiguity and eventually removed it altogether. This proposal is distinct from the stereochemical and the coevolution theories because they do not contemplate any ambiguity in the genetic code, and it is distinct from the error-minimization theory because ambiguity-reduction is fundamentally different from error-minimization. The concept of ambiguity-reduction has been repeatedly mentioned in the scientific literature, but so far it has remained only an abstract possibility because no model has been proposed for its mechanism. Such a model is described in the present article and may be the first step in a new approach to the study of the evolution of the genetic code. (shrink)

Generelle Morphologie der Organismen - Allgemeine Grundzuge der organischen Formen-Wissenschaft mechanisch begrundet durch die von Charles Darwin reformierte Deskendenz-Theorie ist ein unveranderter, hochwertiger Nachdruck der Originalausgabe aus dem Jahr 1866. Hansebooks ist Herausgeber von Literatur zu unterschiedlichen Themengebieten wie Forschung und Wissenschaft, Reisen und Expeditionen, Kochen und Ernahrung, Medizin und weiteren Genres.Der Schwerpunkt des Verlages liegt auf dem Erhalt historischer Literatur.Viele Werke historischer Schriftsteller und Wissenschaftler sind heute nur noch als Antiquitaten erhaltlich. Hansebooks verlegt diese Bucher neu und tragt damit (...) zum Erhalt selten gewordener Literatur und historischem Wissen auch fur die Zukunft bei. (shrink)