有機化学: 現在の研究
オープンアクセス
ISSN: 2161-0401
ISSN: 2161-0401
Rob Hengeveld
This article reviews the main arguments on the nature of the early startu p of life. It first puts the biogenetical processes into a physical and systems-theoretical perspective. Biogenesis in this case would not be about the construction of individual molecules according to a chemical approach, but about building up an energetically selfsustaining, dynamically organized chemical system from scratch. Initially, this system would have separated out from generally operating physicochemical processes, gradually becoming more independent of them. As a system, it had to build up its structure stepwise, each stage being more complex and stable than the previous one, without, however, changing its basic structure too much; as long as the structure of a system stays intact, it still operates in the same way even if chemical constituents change. This property of a system became especially useful when the systems, which had already evolved and operated for some 1.3 billion years, had to adapt to new environmental conditions at the time of the Great Oxygen Event, the GOE, and some 2.5 billion years ago. As energy processing systems, their constituent molecules carry the energy and can as such be replaced by other, more efficient ones as soon as the system require, or as soon as external chemical conditions change. It is the energy flow that started up initially and that as kept running both uninterruptedly and faster ever since, and it is the energy flow that shaped both the system’s structure as well as that of its constituent molecules. For this flow to continue, the system kept changing chemically, but for this to happen the general physical conditions of the environment need to have remained more or less the same.