MEDICAL BIOLOGY, HUMAN ANATOMY, PHYSIOLOGY AND PATHOLOGY - Ya.I.Fedoniuk 2010

BIOLOGY

CHAPTER 2. BIOGEOCENOTIC LEVEL OF LIFE ORGANIZATION AND HUMAN PLACE IN IT

2.8. BIOSPHERE AND HUMAN

The Biosphere

The biosphere (from Greek bios — life, sphaira — sphere) is the part of the Earth's shells (atmosphere, hydrosphere, lithosphere) inhabited by living organisms and actively transformed by them. The term "biosphere" was introduced by the Austrian geologist E. Suess. The Doctrine of the biosphere was developed by Academician V.I. Vernadsky (1863–1945). The biosphere comprises: 1) living matter, formed by the totality of organisms; 2) biogenic matter, created and transformed in The process of Organism жизнедеятельности (atmospheric gases, coal, oil, shales, limestones, etc.); 3) inert matter, formed without the participation of living organisms (products of tectonic activity, meteorites); 4) bio-inert matter, which is a joint product of the vital activity of organisms and abiogenic processes (soil).

The BOUNDARIES OF THE biosphere are determined by the distribution range of organisms within the Earth's geospheres: the atmosphere, hydrosphere, and lithosphere. The upper limit of the biosphere lies at an altitude of approximately 20 km. The limiting factor for colonization in the atmosphere is the intensity of ultraviolet radiation, which increases with altitude. Practically all living matter penetrating above the atmospheric ozone layer is destroyed. In the hydrosphere, the biosphere extends to the entire depth of the World Ocean, as confirmed by the discovery of living organisms and organic deposits down to depths of 10-11 km. In the lithosphere, living organisms have been found at depths of up to approximately 7.5 km.

The totality of All living organisms on Earth is called living matter (according to V.I. Vernadsky's terminology). Living matter accounts for only about 0.01% of the Earth's crust mass by biomass, yet it plays a leading role in biogeochemical processes. The oxygen we breathe and the ozone layer protecting us from the harmful effects of cosmic radiation are created by living organisms; organisms also form the reserves of carbon dioxide in the atmosphere essential for green plants. As a result of Photosynthesis, 115x10⁹ t of dry organic matter and 123x10⁹ t of oxygen are produced annually. Furthermore, photosynthesis involves the annual uptake of 6x10⁹ t of nitrogen, 2x10⁹ t of phosphorus, and other elements. These figures demonstrate that living matter performs immense geochemical work, driving the transformation of the atmosphere, hydrosphere, and lithosphere on a Geological Time Scale.

In addition to the presence of living organisms, another crucial feature of the biosphere is the existence of biotic cycles (biogeochemical cycles) of chemical elements, primarily those termed biogenic. Through METABOLISM, reproduction, and wide dispersal, living organisms drive the biogenic migration of atoms. Throughout the existence of the biosphere, the atoms of most elements have repeatedly passed through the bodies of living organisms. The activity of organisms determines the COMPOSITION OF THE atmosphere, the Composition and Structure of soils, and the constitution of many substances in the hydrosphere. The global biotic cycle is carried out with the participation of all organisms inhabiting the planet. It consists in the Circulation of substances between the soil, atmosphere, hydrosphere, and living organisms. Utilizing inorganic substances, green plants harness solar energy to synthesize organic matter, which serves as food for heterotrophic consumers. Other heterotrophic organisms decompose the organic matter of dead bodies, converting it into Mineral Substances that are subsequently utilized by plants for new organic syntheses. Thus, The primary function of the biosphere is the cycling of matter and energy.

Human Evolution and The formation of human society took place in close connection with the environment. Humans are part of the biosphere and cannot be separated from it. However, they represent a novel and distinct factor. Humans have introduced reason, labor, and science into the biosphere, becoming a geological force that actively transforms it. Humanity came to realize this primarily when both the positive and negative consequences of its activity upon the biosphere became tangible.

The new state of the biosphere, characterized by the rational regulation of relations between humanity and nature, is called the noosphere (from Greek noos — mind). The term "noosphere" was first proposed in 1927 by the French philosophers E. Le Roy and P. Teilhard de Chardin. The DOCTRINE OF THE noosphere was formulated by V.I. Vernadsky, who attached paramount importance to science in the process of noosphere formation. Introducing scientific ideas about the biosphere and noosphere into the consciousness of students is one of the essential tasks of medical biology as an academic discipline.