Basics of Evolution - O.P. Korzh - 2006

Part II. MACROEVOLUTION

Chapter 14. Progressive Evolution

14.4. Biotechnical and Group Forms of Progress

Morphophysiological progress (a concept and term introduced by O.M. Severtsov) was later conceptualized as having two forms: biotechnical and group.

Its essence lies in The formation of new adaptations that grant respective organisms an advantage in the Struggle for Existence. According to V. Franz, evolutionary transformations of organisms lead to a "biotechnical" perfection of nature, which consists in increasing the efficiency with which various Organs perform specific Functions (Fig. 14.2).

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Fig. 14.2. Evolution of the image-forming mechanism (after E. Hadorn, R. Wehner, 1989):

A - flat eye; B - pit eye; C - chambered eye; D - eye with a lens; 1 - visual receptors (retina); 2 - pigment layer

The most important criterion of biotechnical progress is considered to be the coefficient of performance of organs or Organ Systems, which can be calculated based on the energetic parameters of organisms. The presence of similar organs in various Representatives of the animal and plant kingdoms allows for a comparison of their efficiency, which serves as the basis for examining this form of progress.

However, one should not forget The phenomenon of evolutionary compensation, through which organisms can develop different tendencies to solve identical problems. For instance, in birds as a whole, the best-developed sense organ is Vision, whereas in mammals at the dawn of their evolution, the primary sense was Olfaction, resulting in the superior Development of the corresponding analyzers in each group. The orientation efficiency of fish is primarily ensured by the lateral line system despite relatively poor vision: most species are nearsighted due to accommodation via lens displacement, while other animal species navigate the exact same environment primarily through vision or echolocation (dolphins).

Biotechnical progress pertains to the improvement of organs and organ systems aimed at performing specific tasks.

A consequence of biotechnical progress can be considered the formation of heterobathmy, or mosaic development, in organisms. Consequently, relatively primitive forms may possess certain organs that are functionally more efficient compared to evolutionarily more advanced organisms. For example, the olfactory organs of many Arthropods are significantly more efficient than those of vertebrates; the substrate vibration receptors in certain insects, fish, and amphibians far exceed the functional capabilities of the corresponding organs in mammals or birds.

The necessity for further biotechnical progress in nature is explained by the fact that the gradual reduction of organisms' dependence on the environment requires increasingly complex regulatory mechanisms for both maintaining Homeostasis and interacting with surroundings. This necessitates not only the complexification and refinement of specific organs but also the substantial transformation of entire systems or the formation of new structures. Thus, in the course of evolution, new organ systems gradually emerge—nervous, excretory, circulatory, respiratory; warm-bloodedness, viviparity, and other novel adaptations appear, which positively impact the performance of vital functions by organisms.

As the relationships between organisms and their environment become significantly more complex (which is especially evident in animals), there often arises a need to increase the Amount of Information that can be perceived, efficiently processed, and stored by an individual, translating into personal experience. Therefore, The process of cephalization and the enhancement of analytical capabilities in organisms should be regarded as one of the most important directions in the biotechnical progress of animals.

Biotechnical progress also concerns the need to transform supraorganismal structures. The formation of self-regulatory mechanisms and structures at the population or even ecosystem level proves to be significantly more efficient than individual mechanisms. In plants, the most effective outcome of this phenomenon is stratification (tiering), which allows for the optimal utilization of available resources. Among animals, it is the formation of intrapopulational groupings of various origins and corresponding behaviors that significantly improves the survival efficiency of each individual. The pinnacle of such transformations can be considered the formation of a social lifestyle in certain invertebrate and vertebrate species. For instance, thanks to social behavior, bees and ants are able to regulate the Temperature of their nest, rendering them comparable to homeothermic animals to a certain extent.

The gradual transition from unicellularity to multicellularity, the formation of various organs and organ systems, the creation of intrapopulational structures, and, finally, societies can be viewed as distinct stages of biotechnical progress that determine the efficiency of biological structures (even the levels of life's Organization did not arise simultaneously).

Group progress, also referred to as limited progress, is viewed as a special form of progressive development that enables a distinct, fairly large taxonomic group to occupy a dominant position in the biosphere during a specific historical period due to its general level of organization and complex of fundamental adaptations.

Every taxonomic group at the rank of phylum or class is characterized by a specific bauplan (body plan), which facilitates the expansion of its representatives and specialization for various living conditions within a specific adaptive zone. On the other hand, this exact body plan also imposes significant restrictions on the dispersal of these organisms beyond the boundaries of that same zone.

For example, amphibians as the first terrestrial vertebrates possessed a rather progressive complex of traits compared to fish (Lungs, two circulatory loops, limb girdles, etc.) that allowed them to colonize land, which can be viewed as an example of group progress. Conversely, imperfections in reproductive processes, integuments, inefficient Water-Salt METABOLISM, cutaneous Respiration, and other factors imposed restrictions on the distribution of its representatives and led to the extinction of A large number of primitive, relatively unspecialized forms due to competition with more progressive reptiles.

Group progress can be regarded as an elementary stage of unlimited progress. Its main criterion is considered to be the improvement of the morphophysiological ORGANIZATION OF THE entire group while preserving the general body plan. Since The Development of the entire group takes place within the conditions of a specific adaptive zone, group progress remains correspondingly limited by that zone. Moving beyond its limits requires substantial transformations of an arromorphic nature (see the chapter on phylogeny directions), which leads to A change in the general body plan, while the resulting arrogenesis connects individual groups into overall unlimited progress.

The most important differences between group and biotechnical progress lie in the fact that the former concerns the Progressive development of the morphophysiological structures of a specific group. Biotechnical progress is also based on the morphophysiological transformations of organisms, but only regarding specific organs in comparison with other representatives of the organic world. Group progress partially overlaps with biological progress, since the acquisition of any new positive traits by a group always contributes to biological progress. At the same time, this latter form of progress is temporary and always transitions into a state of stabilization or even regression. Group progress, as a specific stage of unlimited progress, retains The Significance of a stepping stone in evolutionary development regardless of the Current state of the respective group (even in the case of the complete extinction of its representatives—for example, trilobites, stegocephalians, dinosaurs, and certain other large groups of extinct organisms can serve as striking Examples of group progress in the past).