Closure of Earth’s Biosphere: Evolution and Current State
2019
Sergey I. Bartsev | Andrey G. Degermendzhi | Antonina B. Sarangova
The existence of the biosphere is determined by the presence of a constant circulation of substances, carried out by a highly branched trophic network of mainly closed material loops. How this largely self-contained system formed remains unclear. The theory of evolution cannot help answer this question since the closure of the biosphere is not an adaptive trait of an individual – this is the essence of the Vernadsky-Darwin paradox. The present paper discusses stages of the formation of the biosphere in the context of closure – a key property and parameter of the biosphere – and possible approaches to resolving the paradox. The authors assume that the appearance of the first living organisms did not mean the appearance of the biosphere as a system of interacting components. The formation of the biosphere in the true sense of the word was associated with the appearance of predation approximately 500 million years ago and the emergence of a highly branched trophic network. The authors obtain simple estimates showing that, on the one hand, living organisms are potentially capable of changing their environment at the global level in a negligible geological time period but, on the other hand, are capable of maintaining an accurate balance of global material cycling for several tens of thousands of years. A simple model was used to show the effect of stoichiometric constraints on the formation of closed material flow in simple ecosystems and to demonstrate the need for increased diversity at trophic levels to overcome these stoichiometric constraints
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