Chemical synthetic biology.

Although both the most popular form of synthetic biology (SB) and chemical synthetic biology (CSB) share the biotechnologically useful aim of making new forms of life, SB does so by using genetic manipulation of extant microorganism, while CSB utilises classic chemical procedures in order to obtain biological structures which are non-existent in nature. The main query concerning CSB is the philosophical question: why did nature do this, and not that? The idea then is to synthesise alternative structures in order to understand why nature operated in such a particular way. We briefly present here some various examples of CSB, including those cases of nucleic acids synthesised with pyranose instead of ribose, and proteins with a reduced alphabet of amino acids; also we report the developing research on the "never born proteins" (NBP) and "never born RNA" (NBRNA), up to the minimal cell project, where the issue is the preparation of semi-synthetic cells that can perform the basic functions of biological cells.

From Eden to a hell of uniformity? Directed evolution in humans.

For the first time during evolution of life on this planet, a species has acquired the ability to direct its own genetic destiny. Following 200,000 years of evolution, modern man now has the technologies not only to eradicate genetic disease but also to prolong life and enhance desired physical and mental traits. These technologies include preimplantation diagnosis, cloning, and gene therapy in the germline on native chromosomes or by adding artificial ones. At first glance, we should all be in favor of eliminating genetic diseases and enhancing genetic traits. Evolutionary considerations, however, uncover hidden dangers and suggest caution against the total embracement of such actions. The first major concern is that the genome will never be a completely reliable crystal ball for predicting human phenotypes. This is especially true for predictions concerning the performance of alleles in future generations whose populations might be subjected to different environmental and social challenges. The second, and perhaps more important, concern is that the end result of germline intervention and genetic enhancement will likely lead to the impoverishment of gene variants in the human population and deprive us of one of our most valued assets for survival in the future, our genetic diversity.

[Transgenics and controlled evolution]. / Transgênicos e evolução dirigida.

Mutation events are responsible for the generation of genetic variability in the populations enabling the occurrence of natural selection which favors the better-adapted types. The exploitation of this variability, though carried out empirically, dates from ten thousand years ago with the domestication of the first cultivated crops. With the advent of genetics, rational selection procedures were adopted with a view of the genetic breeding of plants, animals and microorganisms which might be of interest to men. Recently, new DNA manipulation techniques came up enabling the transference of genes between organisms, cutting across barriers which hindered crossing between the vegetable, animal, protist and fungus kingdoms. The generation of genetically modified organisms, or transgenics, has aroused a heated and controversial debate in various sectors of our society. Yet we must be cautious before generalizing the use of transgenics since each one should be analyzed at a time for its particular advantages and drawbacks, and for its contribution to the improvement of life quality. This paper also considers recent methods of mutation and in vitro genic recombination.