Closure of Earth’s Biosphere: Evolution and Current State

Abstract

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

The Evolutionary Mechanism of Formation of Biosphere Closure

“…For expression (7) to make sense, the expression in parentheses must be positive. This requirement is met if the ratios of the amounts of nutrients in the biomass of organisms satisfy the following conditions:…”

“…To visualize the feasibility of the presence of the steady closed state in the system under conditions (7), we construct a parametric portrait of the model, that is, we estimate the regions of existence of a steady/quasi-steady state on the plane of the selected parameters. These parameters will be the specific growth rates of the autotrophic component (µ X ) and one of the heterotrophs (µ 1 ) at different values of the stoichiometric composition of the other heterotroph.…”

“…To highlight the key contradiction, a more compact formulation of this paradox was proposed: "The closure of the biosphere is not an adaptive property of an individual (or population)" [7].…”

“…The consequences of breaking the closure of the biosphere will be felt much later than the direct results of selection. Since the closure of the biosphere occurred against the background of natural selection, working in the "orthogonal", if not in the opposite direction, it seems logical to expand the name of this paradox to the Vernadsky-Darwin paradox (VD paradox) [7].…”

“…Most experts tend to believe that life on Earth arose under anaerobic conditions near hydrothermal vents that supply energy for chemoautotrophic synthesis [8][9][10][11]. The alternative hypothesis, which suggests the heterotrophic nature of the first organisms, encounters a number of objections, which are discussed in detail in [7]. It is important that, in any case, the heterotrophic hypothesis leads to the absence of the closure of the material flow and, consequently, to the absence of the biosphere as a system of interactions.…”