Направленность эволюции - Северцов А.С.
ISSN 5—211—00917—7
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There is a range of paleontological and neontological evidence of the in-same adaptive zone. This puts the problem of polyphyly and monophyly as a dependent introduction of the similar and hardly distinguishable forms into the taxonomical problem, not the evolutionary one'.
The organizational prerequisite (preadaptations) which allow for the expansion into the new adaptive zones arise frome the early and rapid specialization which has ocured in the abberant adaptive zones, aspecialiy in the asonal associations. The evolutionary flexibility of these forms which have specialized in a marginal zones is coincident with their heterobatmia. Expansion to the new adaptive zone may be realized either by the shift from the ancestral taxon zone to the new one, or by ,its widening, i. e. involving of the supplementary environment, the lost corresponding to the aromorphic evolution. The complication of the environmental conditions leads to the complication and the progress of the organization. The formation of anamorphosis is a rather slow process. The rates of this process are limited by the formation of the coordination between characters which provide the adaptation both in the previous and in the newly acquired parts of the adaptive zone, and characters which provide the adaptation only to the one of these parts.
The expansion to the new adaptive zone leads to the adaptive radiation of the engaged taxon, with the range of a fan sweep corresponding to the acquired area. Adaptive radiation leads to the splitting of the adaptive zone into subzones and thereby to the substitution of the aromorphosis by the allomorphosis. In the course of this process some taxa are displaced to the abberant (marginal) adaptive zones, the adaptation to which initiating the new aromorphosis.
AIlomorphic evolution according with the zone change or with the adaptation to the zone which has been already occupied may take place for an unlimited time period. However, the continued divergence leads to the further splitting ?of the adaptive zone and thereby, to the specialization of at least a part of the taxa occupying it. In this case, specialization arises from the loss of the heterobatmia. Therefore, if the retarded specialization is accompanied by the decrease in the degree of polyfunctionality of the organs along with the decreas of heterobatmia, this may result in the extinction of such a taxon. However, if the environment remains unchanged, these particular taxa (highly adapted in the specific environmental conditions) tend to persist. On the contrary, the early specialization may give rise to the new aromorphosis. This means that in the course of phylogenesis the number of potential directions for the evolution of the taxon will increase. While the aromorphosis is always succeeded by the allomorphosis, the allomorphosis in not necessary succeeded by specialization. Specialization, appears to be extremely diverse in itself, leading to the three types of effects: to the new aromorphosis, persistance, or extinction. This evolutionary rule points out that the directional, sometimes strictly canalized process of evolution, is nevertheless undetermined, being neither teleological, nor final.
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Оглавление
Hardt'Hue............... g
Глшт 1. НАПРАВЛЕННОСТЬ МИКРОЭВОЛЮЦИИ ... .8
Ы. Популяция под действием вектора отбора, идущего по стабильным
признакам фенотипа............ g
1.2. Популяция под действием вектора отбора, идущего по пластичным признакам фенотипа............. ^g.
1.3. Популяция под действием системы векторов отбора 47
1.4. Необратимость эволюции ...........' ?g.
Глава 2. НАПРАВЛЕННОСТЬ МАКРОЭВОЛЮЦИИ..... 74
2.1. Соотношение микроэволюции и макроэволюции...... 74
2.2. Направленность филогенеза. Общие замечания...... 85
2.3. Функциональная дифференцировка организма ...... 87
2.3.1. Структура и функция . .......... 87
2.3.2. Мультифункциоиальность и множественное обеспечение биологически важных функций . ......... 91
2.3.3. Функциональные изменения органов в ходе филогенеза . . 97
2.4. Целостность организма в ходе филогенеза....... 120
2.-1,1, Координации (филетические корреляции) ...... 120
2.4.2. Типы координации............ 122
2.4.3. Перестройка координации .......... 129
2.5. Направленность филогенеза таксона ......... 137
2.5.1. Адаптивная зона . ........... 138
2.5.2. Освоение новых адаптивных зон......... 144-
2.5.2.1. Экологические аспекты освоения новой зоны . . . 146
2.5.2.2. Морфологические аспекты освоения новой зоны . . 149
2.5.2.3. Организационные предпосылки освоения новых зон . 152
2.5.3. Дивергенция, параллелизм и конвергенция...... 158
2.5.3.1. Дивергенция ........... 158
2.5.3.2. Параллелизм и конвергенция ....... 159
2.5.4. Монофилия и полифилия в происхождении таксонов надвидового ранга . . . ......?
2.6. Главные направления эволюционного процесса...... 183
