New Tendencies in Darwinism

The modern evolutionary theory is an elaboration of the classical Darwinian theory. Apart from such extremely important fields as 'genetics', Darwinism accepted a number of new ideas such as genetic drift and recombination, cooperative evolution, and global biospheric context of evolution.

Mutations do not so often revolutionize populations; mostly, they support its genetic heterogeneity. In accordance with modern views, genetic mutations are not obviously new forms of genes. Usually they are recombinations of existing hereditary material, at the molecular, cellular, organism, and ecosystem levels. Such recombinations can produce a fast evolutionary leap forward. There is a common genetic pool of life; similarity of genes does not necessarily mean cognation.

According to Kimura's theory of 'genetic drift', genes can exist and even breed in a latent form and then rapidly declare themselves. The effect does not contradict Darwinism; it only proposes a broadened understanding of mutations and their formation.

Variability as a result of genetic change is quite typical at the lower level of life. In cells, there is dissipated genetic material, which does not influence its characters, in silent parts in DNA (intrones), in cellular parasites, viruses and plasmids (DNA molecules in the cellular protoplasm, which can be transmitted not only to descendants, but also to neighboring cells).

Although multicellular organisms are protected from genetic material damage by special mechanisms, cases of genetic material transfer can take place for them as well: by viruses, as a result of distant hybridization, etc. Besides, genes, reflecting environment, reflect genes of neighboring organisms. Thus, hereditary units (genes) of all living beings form a closely connected system, a general 'gene pool' of biosphere.

One of the factors of horizontal genetic transfer, great importance of which has been understood lately, is the formation of symbiotic beings. A well-known example of symbiotic organisms is lichen, consisting of two species, fungi and alga, which, in principle, can exist separately. Because of long-standing coevolution, these two species have adjusted their biochemistry and synchronized reproduction. There is a small green sea worm Convoluta roscoffensis, feeding on symbiotic algae; algae germs transfer to the next worm generation through gametes. Most animals need symbiotic microorganisms for effective digestion, luminescent organs of animals are a result of symbiosis with bacteria, etc. One of the most important revolutions in the history of life was the origin of eukar-yotic cells as a result of step-by-step symbiotic integration of several prokaryotic ones that finally shared their genes.

A subject of competitive selection can be a symbiotic system, unifying initial forms, which before had struggled for existence separately. The symbiotic evolutionary theory complements Darwinism with a deeper appreciation of the fundamental cooperative processes, which accompanied the origin and evolution of life.

Each organism has its own place in the biosphere. It cannot evolve separately; it should coordinate its change with connected species. Particularly, evolution ofseparate organisms should not damage biogeochemical cycles. In the course of evolution, the cycles, as well as the biosphere, reproduce themselves as comprehensive wholes.

Although the natural selection operates at the level of individuals, increase in information takes place only at the levels of species and ecosystems. Evolution of the biosphere is a grand process of information collection. The main source of the information storage is the biospheric gene pool.

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