Earth complex evolving systems

The authors suggest that it was the structural diversity of the environment which made biogenesis possible in other words, there was an enormous selection of regions with different properties and states on the young Earth which acted as stimuli for the increasing complexity of the evolving systems. As complexity increased, those regions of the primeval Earth which were not available for earlier, more primitive systems could be colonized . 

The constant transport of material within and through the geospheres is powered by the sun and by the heat of the Earth s interior. A simple diagram of these geospheric concepts and the energy that moves material within them is presented in Fig. 1-1. The result of the interactions shown in Plate 1 and Fig. 1-1 is an Earth system that is complex, coupled, and evolving. 

It is difficult to imagine just how these molecules, once formed, somehow evolved further into the extraordinarily complex systems afforded by even the simplest bacterium able to utilize energy from the sun to support and reproduce itself. Nonetheless, synthetic peptides do coil and aggregate rather like natural proteins, and some also have shown catalytic activities characteristic of natural enzymes. One would hope that some kind of life would be found elsewhere in the solar system, the analysis of which would help us to better understand how life began on earth. 

An RNA that exhibits enzyme-Hke activity is called a ribozyme. The discovery of ribozymes had a great impact on research into the origins of life. Identifying catalytic capabilities in RNA, an information molecule, led to a new theory the RNA world hypothesis. This suggests that RNA was the first life form on Earth, and when it first evolved it performed both catalytic and enzymatic functions. The natural selection process associated with evolution eventually caused the RNA to evolve into the highly sophisticated supramolecular systems observed in the complex life forms present today. 

Competition drives the emergence of natural selection. Such behavior appears to be inevitable in any self-replicating chemical system in which resources are limited and some molecules have the ability to mutate. Over time, more efficient networks of autocatalytic molecules will increase in concentration at the expense of less efficient networks. In such a competitive milieu the emergence of increasing molecular complexity is inevitable new chemical pathways overlay the old. So it is that life has continued to evolve over the past four billion years of Earth history. 

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