Biological progress is the only direction of evolution that led to the emergence of man. This direction causes the transition in the process of evolution to the social level.
As is known, the path of achieving biological progress, the course of historical development (phylogeny) for each specific taxon (group) depends on the adaptive zone in which, in fact, this taxon evolves. The possibilities of restructuring in the organizational structure of the group are of no small importance.
Touching on the main problem that biological progress solves, scientists pay attention to the role of each available factor in determining a particular direction in development. In other words, the study of this particular question makes it possible to see how adaptation can improve and evolution in general can occur.
JB Lamarck was the first to study this area. The scientist divided biological progress into two types. To the first, he assigned a gradation - an increase in the organizational level. The second of them, according to the scientist, is the formation of a variety of types of organization at each specific level. The scientist believed that these two processes are independent of each other. Thus, gradation is conditioned by an inner striving for perfection, diversity is formed under the influence of the environment. At the same time, it should be said that, despite the fact that Zh. B. Lamarck misinterpreted the mechanism of the two directions, their very existence is an objective fact.
Darwin considered biological progress in a different way. He equalized the concepts of evolution and adaptation. Because of this, according to Charles Darwin, the increase in the organizational level was only a partial result of this whole process. As a rule, with the complexity of the organization in the process of evolution, an increase in fitness is combined. In the process of divergence of signs (divergence) there is a constant complication of the biotic environment. Darwin further suggested that adaptation to a more complex environment can be achieved through only a more complex structure of the organism. Subsequently, biological progress was studied in two ways. The studies were conducted in Russia by A. Severtsov and abroad by J. Huxley and B. Rensch.
Like JB Lamarck, B. Rensch believed that the development of evolution is possible not only vertically, but also horizontally. The formation of diversity at one level of the organization was called Renshom cladogenesis, and the output to a new level is anagenesis. In turn, J. Huxley returned to the definition of "grads" (steps), proposed by JB Lamarck. At the same time, the scientist singled out the third direction, according to which biological progress takes place, calling it stasigenesis. This direction he considered a phenomenon of stabilization, the preservation of persistent, unchanging branches. Analyzing all directions, J. Huxley came to the question of where evolutionary development could lead at all and what could become the criterion of its progressiveness. As a result, the paradox of J. Huxley arose: who is more progressive - the tuberculosis bacillus provoking the disease of man, or the person himself?
The scientist tried to solve the emerging questions in his theory of unlimited and limited development. In accordance with this theory, evolution, of course, is biological progress. However, this development is group, and therefore limited. Passing from one stage to another, each taxon (group) progresses, but, at the same time, it comes to extinction, that is, to stasigenesis. In this case, only one direction of development leading to the appearance of a person is unlimited. This is due, mainly, to an entirely new evolutionary level - social.