The term biosphere , which is also possible to write without the tilde in the OR (biosphere) as you accept the Royal Spanish Academy , can refer to all the living organisms that inhabit our planet or to the group that forms the means that allow the subsistence and development of the different species.
Austrian geologist Eduard Suess (1831 -1914 ) was who, in 1875 , proposed the notion of biosphere. Russian Vladimir Ivanovich Vernadski (1863 -1945 ), decades later, expanded the concept .
The biosphere is generally understood as a system that make up all living beings and the links they establish with each other. Its about planetary ecosystem It includes multiple life forms and that, up to a certain point, can regulate its evolution and balance.
The biosphere develops along all levels of the surface of the land , including the bottom of the seas. In the case of the oceans, living beings are distributed in the so-called photic zone , which is the surface layer to which the sun's rays reach. In deeper areas, the density of life is low.
When they include the deepest level of the earth's crust, where certain organisms live, we talk about deep biosphere . There exist bacteria that, through the chemosynthesis , can develop. This verification of the existence of life in the deep biosphere produced changes in various scientific theories as it demonstrated biological viability in extreme conditions, even without the presence of energy from the sun.
Until the deep biosphere was discovered, therefore, it was believed that life was not possible in the absence of light solar. As had happened before and will happen again, the human being faced one of his mistakes in understanding the phenomena of nature and thus widened the horizon of his knowledge. One of the consequences of this greater intellectual flexibility was the increasing acceptance of the possibility of extraterrestrial life : living beings can exist in a wide range of conditions, broader than scientists believed, and therefore it was not logical to rule out that biology surprised them once again.
By accepting that life on other planets can be viable, science contemplates that they progress in the formation of biospheres different from those known on Earth, so that parameters according to which experts measure the possibility of the emergence of life are neither absolute nor valid in all cases.
Life is organized in such a way that you can appreciate a hierarchy with more than one level of complexity, where the systems considered minor work together to give rise to the training of the elderly, which enjoy more variety and complexity. These systems they organize independently and can control their own state with varying degrees of precision.
With respect to self control of the systems, the highest peak is found at the level of organisms and cells; Let us not forget that only one cell is needed to find an autonomous organism, as in the case of single-celled organisms. At the ecosystem level, we can observe a lower degree of self-control, since its organization is governed by negative feedback mechanisms.
Certain authors specialized in this subject, among which were Vernadski and James Lovelock They pointed out that the biosphere is able to regulate its structure and composition (a property that organisms possess, called homeostasis ), as well as the pace of the exchange and internal processes (homeorresis ).