Does population ecology have general laws? P. V. Turchin
Genetic aspects of species structure of the compost worm Eisenia foetida (Sav.) (Oligochaeta, Lumbricidae) N. M. Bolotetskii, . . Kodolova
Decentralized self-regulation of the integrity of colonial organisms N. N. Marfenin
Role of the skeleton in determination of the branching points in hydroid colonies I. A. Kossevitch
Affect of variable phases of tide cycle on reproduction of Laomedea flexuosa (Hydroidea, Thecaphora) S. A. Belorustseva, N. N. Marfenin
Some regularities in the development of encrusting colonies of Crihrilina annulata (Fabricius, 1780) E. B. Yagunova
Analysis of possible mechanisms of regulation of root branching M. E. Ploshchinskaya, V. B. Ivanov, S. A. Salmin, E. I. Bystrova
Reviews
On the book of H. Caswell "Matrix population models: construction, analysis and interpretation' D. 0. Logofet
On the book of Zorina Z.A. and Poletaeva I.I. "Zoopsychology. Elementary thinking of animals: Handbook" V. V. Shulgovsky
Scientific Discussion
Systematics on the threshold of XXI century. Traditional principles and bases from today point of view A. K. Skvortsov
Information for authors
Does Population Ecology Have General Laws?
Peter Turchin
Dept. Ecology and Evolutionary Biology, University of Connecticut, Storrs, CT 06269-3043, USA e-mail: peter.turchin@uconn.edu
There is a widespread opinion among ecologists that ecology lacks general laws. In this paper the author argues that this opinion is mistaken. Taking the case of population dynamics, the author points out that there are several very general law-like propositions that provide the theoretical basis for most population dynamics models that were developed to address specific issues. Some of these foundational principles, like the law of exponential growth, are logically very similar to certain law of physics (Newton's law of intertia, for example, is almost a direct analogue of exponential growth). The author discusses two other principles (population self- limitation and resource-consumer oscillations), as well as the more elementary postulates that underlie them. None of the "laws" that the author proposes for population ecology are new. Collectively ecologists have been using these general principles in guiding development of their models and experiments since the days of Lotka, Volterra, and Cause.
Genetic Aspects of Species Structure of the Compost Worm Eisenia foetida (Sav.) (Oligochaeta, Lumbricidae)
N. M. Bolotetskii, . . Kodolova
Laboratory of Animal Development, Biological Faculty, M.V. Lomonosov Moscow University, Vorob'evy Gory, Moscow 119899, Russia
Distribution of frequencies alleles of polymorphous loci of peroxidase (Pox), leucineaminopeptidase (Lap), phosphoglucomutase (Pgm) and octanoldegydrogenase (Odh) were studied by electrophoresis in polyacryla-mide gel in 22 local samples of Esenia foetida in Russia (European part), Ukraine, Kazakhstan and Kirghizia. The samples form two spatial groups - "northern" and "southern", distinguished by set of alleles in every studied locus. The "northern" groups is formed by local populations of European Russia from Murmansk region on the north to Smolensk region on the south, and also by cultivated population of selection line "red California hybrid". The "southern" group is formed by local populations on the territory of Russia from middle Volga to the North Caucasus, Ukraine, Kazakhstan, Kirghizia, cultivated populations from Kirghizia and Portugal. High degree of genetic difference between samples and independence of alleles frequencies distribution from geographical location and habitat allows to consider almost all studied groups as separate populations. Statistical processing of Nei genetic distances (Nei, 1972) revealed reliable differences between averages of within- and intergroup distances. Besides, discrete differences between intervals of significance of genetic distances were revealed. The results indicate that on the studied territory E. foetida has hierarchical two level structure. The first level is formed by local populations differed by frequency of the same alleles. The second level is formed by local populations, united into spatial groups, that are qualitatively distinguished by the set of alleles in the same loci.
Decentralized Self-regulation of the Integrity of Colonial Organisms
N. N. Marfenin
Dept. Invertebrate Zoology, Biological Faculty, M.V. Lomonosov Moscow University, Moscow 119899, Russia e-mail: marfenin@Nmarfenin. home.bio.msu.ru
The self-regulation of the integrity of colonial organism is accomplished without any central system organs. Abundance of similar structures, parallelism and synchrony of the processes form the basis for self-regulation, thus creating the independent mechanism of the internal coordination of the processes. Decentralized regulation of the integrity is much more economical then the centralized regulation, because it does not demand large volume of information, consequent increase in complexity of its processing and unavoidable problems with coordination. The principles of decentralized self-regulation, addressed in this paper, can be use not only in biology, but also in sociology, psychology, modeling, neuroformatics, etc. ,
I. A. Kossevitch
Role of the skeleton in determination of the branching points in hydroid colonies
Dept. Invertebrate Zoology, M.V. Lomonosov Moscow State University, Russia e-mail: ikos@mail.ru
Colonial hydroids of the suborder Thecaphora have rigid outer skeleton that possesses species- specific shape of the colony elements. Organisation of the elements within a colony shows strict spatial patterning. The points of branching (emergence of the new growing tip) within shoots are strictly determined and show positive correlation with the place of the most pronounced curvature of the elements skeleton. As it was shown earlier, the shoot growing tip, after emergence, performs its program of functioning independently from the colony condition. Several modifications of experiments with grafting of the growing tip together with rotation around its longitudinal axis were fulfilled. As the result of such grafting the normal orientation of the formed skeleton was altered. In overwhelming cases of further tip growth and shoot development the new growing tip emerged in correspondence with new orientation of the formed skeleton. The orientation of the hydranth of the maternal shoot element had no effect upon the orientation of the new tip emergence after grafting. It is supposed that the place of the new tip emergence is regulated hierarchically. At first level, the interaction of the soft tissues with the skeleton has priority. Anisotropy of mechanical tensions within cell layers due to interaction with the skeleton at the point of its most curvature serves as a primary stimulus in the chain of events leading to the initiation of the new growing tip. If this does not work the intrinsic tissue property (polarity) determines the place of the tip emergence. Such two-level mechanism of determination of the place of the new tip emergence in sympodial shoots stabilises spatial organisation of the entire shoot and decreases the probability of epigenetic mistakes.
Affect of Variable Phases of Tide Cycle on Reproduction of Laomedea Flexuosa (Hydroidea, Thecaphora)
S. A. Belorustseva, N. N. Marfenin
Dept. Invertebrate Zoology, Biological Faculty, M.V. Lomonosov Moscow University, Moscow 119899, Russia e-mail: nwrfenin@NMarfenin.home.bio.insu.ru
Colonial hydroid Laomedea flexuosa inhabits the narrow belt of low littoral zone in the White Sea. What is a reason of so limited habitat? The authors studied the time ofplanulae release and its behavior during free swimming stages and settlement of larvae in nature and under laboratory conditions. Three methods were used to registrate the tidal dependent dynamic of planulae release: 1) plankton collecting bags around Fucus inflatus kelp with mature hydroids colonies; 2) active stirring kelps with hydroids in container with water, which is an old way to stimulate planulae release; 3) direct account of the mature planulae into gonangia. The dynamic of intensity of L. flexuosa planulae release was investigated according 3-A phases of tidal cycle. All data were statistically tested. For L. flexuosa a moment of general larvae release was found in phase with the period of low water. This correlation could explain strict limitation in occurance of L. flexuosa only in the lower part of in-tertidal zone. Laboratory experiments show that planulae release is stimulated by littoral drainage, and renewal of water movement during the beginning of tide. The decrease in time of planulae settlement is an affective way for marine sedentary species to stay in a narrow zone of optimal habitat.
E. B. Yagunova
Dep. Invertebrate Zoology, Biology and Soil Faculty, St.-Petersburg State University, Universitetskaya nab. 719, St.-Petersburg 199034, Russia
The growth of encrusting colonies was studied with mathematical model. It was shown that encrusting growth takes place under increasing competition for the substrate inside the colony. The model was tested on the example of Crihrilina annulata collected in White Sea on Laminaria saccarina. All colonies were mapped, zooids were measured and genealogical connections between them were established. A number of gradients were revealed by statistical methods. The intensity of budding decreases in astogeny according to theoretical predictions. It was shown that development of Cribrilina annulata colonies is strictly determined by gradients that can be caused by shortage of substrate space. It leads to the suppresion of budding and changing in zooid size. Increasing substrate shortage is predictable and caused by the regularities in of zooid budding. The growth of colony stops after exhausting of potentially available substrate.
Analysis of Possible Mechanisms of Regulation of Root Branching
M. E. Ploshchinskaya, V. B. Ivanov, S. A. Salmin, E. I. Bystrova
K.A. Timiryazev Institute of Plant Physiology, Russian Academy of Science, Botanicheskaya ul. 35, Moscow 127276, e-mail: ivanov@ippras.ru
Orel State University, Komsomolskaya ul. 95, Orel 302015, Russia e-mail: rector@on.oryol.ru
The formation of lateral roots under the influence of growth inhibitors and phytohormons were studied with germs of corn and flax. All corn primordiums develop into the lateral roots without dormancy period, while some flax primordiums are delayed in development. Removal of root apical meristem (decapitation) does not result in the increase in number of lateral roots of corn germs. Decapitation of flax germs induces the development of some dormant primordiums, that leads to the considerable increase in number of lateral roots. Formation of additional primordium under decapitation does not take place. Auxin stimulates the formation of additional primordiums in flax, but does not effect the number of mature lateral roots. In corn germs synthetic auxin stimulates the development of additional primordiums in root zone, where primordiums are forming after the disturbance. It is shown that the time of primordium development does not change under inhibitor influence, if they do not selectively effect mitoses. It seems that auxins regulate initiation of pericycle division and formation of primordiums of lateral roots on the stage of development of meristematic protuberance. Cytokinins influence the development of already existed primordiums of lateral roots but do not effect the formation of new ones. Constancy of time of primordium formation and independence of their development on the state of the main root need future investigations. The authors suppose that regulation of these processes is non- hormonal.
A. K. Skvortsoff
Main Botanical Garden, Russian Academy of Science, Botanicheskaya ul. 4, Moscow 127276, Russia
Systematics as regarded is a purely theoretical domain of biology, and its product, system, as a specific biological theory, or a topologo-genetic model of the biota. Linnaeus was the first to introduce the idea of system and the systematic approach into the natural history. The advent of evolutionism brought new meaning to the old term "affinity", so Linnaeus' slogan of natural system got new life, and Linnaeus taxonomy assimilated the evolutionary ideology quite naturally and much easier than many other departments of biology. The difference between natural and artificial systems is remaining, and it is in their goals, as formulated by Linnaeus: heuristic of the former and cataloguing of the latter. Linnaeus' clairvoyance discovered the existence of an infrageneric level of genetic integration provable by naturalists' experience. He chose for it the designation of "species" and laid it down as primary, basic unit of his system. This is plainly evident from his own writings; the story about Linnaean species being products of a logical division of genera is a pure fiction. Modem populational model of species, by 3 important criteria, appears to be more akin to the Linneaean one than to the ideas of Lamar-ckism and early Darwinism. Systematic approach focuses rather on the interrelations among elements and their relative position, then on the properties and qualities of separately treated individual elements. In the development of systematics the aspect of "nexification" (study of connections) has been continuously gaining attention especially regarding the nomenclature where connotation has been totally forced out by denotation.