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A correlation has been made between the phases of various evolving natural systems - magmatic, biological and social. The cycle of existence of these systems encompasses four stages - growth, internal development, stationary state (maturity), ageing. On the basis of the correlations it is shown that the modern period of the evolution of humankind corresponds to the end of the growth stage; the age of humankind currently corresponds roughly to the age of a 17-year-old man. The meaning of the existence of humankind as a planetary system is examined, and the need for an elaboration of a long-term strategic program of the evolution of civilization for promoting fundamental transition from the growth stage to that of internal development is substantiated. (Reprinted by permission of the publisher.)

The article shows the compatibility of the concept of thermodynamic inversion (TI) of the origin of life with the theory of stress in (micro)biology. According to the proposed TI concept, the first microorganisms on Earth were formed through an effective (intensified and purposeful) response of organic microsystems to incessant oscillations of physicochemical parameters (i.e., to periodic stress) in a hydrothermal environment. This approach allows us to explain the ability of contemporary microorganisms to respond to stress at the individual and population levels. The ability of microorganisms to effectively react to environmental stress factors is corroborated by a number of molecular and other mechanisms that are described in the article.

We present a case for the exploration of Venus as an astrobiology target-(1) investigations focused on the likelihood that liquid water existed on the surface in the past, leading to the potential for the origin and evolution of life, (2) investigations into the potential for habitable zones within Venus' present-day clouds and Venus-like exo atmospheres, (3) theoretical investigations into how active aerobiology may impact the radiative energy balance of Venus' clouds and Venus-like atmospheres, and (4) application of these investigative approaches toward better understanding the atmospheric dynamics and habitability of exoplanets. The proximity of Venus to Earth, guidance for exoplanet habitability investigations, and access to the potential cloud habitable layer and surface for prolonged in situ extended measurements together make the planet a very attractive target for near term astrobiological exploration.

Two processes required for life's origin are condensation reactions that produce essential biopolymers by a nonenzymatic reaction, and self-assembly of membranous compartments that encapsulate the polymers into populations of protocells. Because life today thrives not just in the temperate ocean and lakes but also in extreme conditions of temperature, salinity, and pH, there is a general assumption that any form of liquid water would be sufficient to support the origin of life as long as there are sources of chemical energy and simple organic compounds. We argue here that the first forms of life would be physically and chemically fragile and would be strongly affected by ionic solutes and pH. A hypothesis emerges from this statement that hot springs associated with volcanic land masses have an ionic composition more conducive to self-assembly and polymerization than seawater. Here we have compared the ionic solutes of seawater with those of terrestrial hot springs. We then describe preliminary experimental results that show how the hypothesis can be tested in a prebiotic analog environment.

Biological organization arises under thermodynamic inversion in prebiotic systems that provide the prevalence of free energy and information contribution over the entropy contribution. The inversion might occur under specific far-from-equilibrium conditions in prebiotic systems oscillating around the bifurcation point. At the inversion moment, (physical) information characteristic of non-biological systems acquires the new features: functionality, purposefulness, and control over the life processes, which transform it into biological information. Random sequences of amino acids and nucleotides, spontaneously synthesized in the prebiotic microsystem, in the primary living unit (probiont) re-assemble into functional sequences, involved into bioinformation circulation through nucleoprotein interaction, resulted in the genetic code emergence. According to the proposed concept, oscillating three-dimensional prebiotic microsystems transformed into probionts in the changeable hydrothermal medium of the early Earth. The inversion concept states that spontaneous (accidental, random) transformations in prebiotic systems cannot produce life; it is only non-spontaneous (perspective, purposeful) transformations, which are the result of thermodynamic inversion, that lead to the negentropy conversion of prebiotic systems into initial living units.

Basic provisions of an original concept of biosphere germination are enumerated. Formation of primary microorganisms and communities is considered from the viewpoint of crucial transformations in compartments of organic matter that led to the emergence of fundamental properties of biological systems. The necessary initial condition was the transition of organic microsystems in the bifurcation state which maintained continuing dynamic processes in them. The decisive stage of transformation of microsystems in protobionts (initial forms of life) comprised their acquiring ability to concentrate free energy and information at the expense of fortified reactions to external influences, exerted by the fluctuating hydrothermal environment. The primary biosphere was formed during the evolution of microorganism types in the direction probionts--progenotes--prokaryotes.

An important question guiding research on the origin of life concerns the environmental conditions where molecular systems with the properties of life first appeared on the early Earth. An appropriate site would require liquid water, a source of organic compounds, a source of energy to drive polymerization reactions and a process by which the compounds were sufficiently concentrated to undergo physical and chemical interactions. One such site is a geothermal setting, in which organic compounds interact with mineral surfaces to promote self-assembly and polymerization reactions. Here, we report an initial study of two geothermal sites where mixtures of representative organic solutes (amino acids, nucleobases, a fatty acid and glycerol) and phosphate were mixed with high-temperature water in clay-lined pools. Most of the added organics and phosphate were removed from solution with half-times measured in minutes to a few hours. Analysis of the clay, primarily smectite and kaolin, showed that the organics were adsorbed to the mineral surfaces at the acidic pH of the pools, but could subsequently be released in basic solutions. These results help to constrain the range of possible environments for the origin of life. A site conducive to self-assembly of organic solutes would be an aqueous environment relatively low in ionic solutes, at an intermediate temperature range and neutral pH ranges, in which cyclic concentration of the solutes can occur by transient dry intervals.