The questions concerning the origin and early evolution of life are mostly approached with focus on the complex problems of biomolecular autosynthesis. The specialists in this field are chemists and molecular biologists. They are seriously concerned with the staggering difficulties met in their own realm and tend to avoid dealing with the additional severe environmental limitations that are suggested by our general knowledge of planetary and spatial physics and chemistry. This purposeful neglect is often rationalized by the impression that their counterparts in the environmental sciences are groping in the dark and that, allowing enough time, shifting geochemical consensus will give back unlimited freedom to organic suppositions.

Planetary chemists on the other hand draw on their experience in studying present-day natural processes with reflection in the geological record. This makes them fit to attempt reconstruction of the environmental processes that may have controlled biopoesis. However, they often labor under the impression that any kind of organic molecule that can be conjured up in a harsh Archaean environment signifies the emergence of life.

The gap between the two cultures has been narrowed, but not closed, by the extensive interdisciplinary activities in this field, fostered chiefly by NASA and other national and international agencies with an interest in exploring the origin of life and the possibility of its emergence also on other worlds. The present meeting gives an opportunity for another step toward defining the central problems and for reviewing relevant progress. This presentation will aim at the following central topics:

" Environmental requirements for the generation of source molecules needed for metabolism and for generation and transduction of information

" Factors in the primordial planetary and spatial environments that favor constructive
processes vs. detrimental conditions

" Physically and chemically realistic conjectures that can be made to overcome apparent hindrances

" Autosynthetic generation, encoding and propagation of molecules capable of information transduction

" Modeling of primordial metabolism

" Concentration and encapsulation of source molecules from highly dilute state; the improbability of a "primordial soup"

" Earliest planetary evidence for life and its relation to the phylogenetic tree on Earth