[Some problems of the evolutionary adaptatiogenesis].

Evolution of organisms is adaptive process as a whole, but its adaptiveness is fully revealed in long periods of phylogenesis. To form the complex adaptations, the phyletic evolution is more favourable than relatively short-term processes of speciation. Selection can influence on a given character of organism only after achievement of some minimal selectable degree of its development, that is specific for each adaptation. For some complex adaptations, the minimal selectable value of the character can be essentially higher than the initial degree of its expression. In such cases the corresponding adaptations evolve either on the basis of the morpho-functional preadaptations or using some relatively large hereditary changes ("saltations") as the elementary evolutionary material for selection. The negative consequences of such saltations can be mitigated by the compensatory ontogenetic modifications. Elucidation of the minimal selectable value of characters seems to be useful also to evaluate probability of the hypotheses explaining adaptive causes of corresponding evolutionary transformations. The notions of the ecto- and endosomatic organs (after A.N. Severtzov, 1939) are relative ones. The primary evolutionary changes (protallaxes) can arise in any organism system and cause the arising of secondary alterations (deutallaxes, or internal adaptations) in other system.

[Phenogenetic variability and population meronomy].

In accordance with M.A. Shishkin's epigenetic evolutionary theory and S.V. Meyen's concept of meron, N.P. Krenke's "phenogenetic variability" can be considered as a realization of developmentally determined laws of possible transformations of particular characters (morphogenetic realization of meron). It includes two components: deterministic (organizing) one and stochastic (random) one. Organizing includes (epigenetic variability) represents a canalized component of morphogenesis determined by creode structure and arrangement of epigenetic thresholds, which alows to speak about morphogenetic rule of meronomic transformations. Random (realized) variability corresponds with stochastic component of morphogenesis, which makes it possible a spontaneous shifting of available developmental programs and selection of alternative subcreodes. Concepts of "population epigenetic landscape", "population ontogenesis" and "population meronomy" are introduced. Population ontogenesis (PO) can be considered as a peculiar deformation of species developmental program common to all individuals in particular population. This deformation is historically adjusted to concrete environmental conditions by natural selection. PO reflects general set of potential developmental patterns in concrete population, and it should be peculiar and unique one in respect to the whole species. It may be assumed that each individual contains information about invariant population epigenetic landscape (PEL), and thereby discrete individual phenotypes represent a probabilistic copy of general population epigenetic pattern. Analysis of bilateral structures among members of the same generation permits to visualize the principal pattern of PEL. Epigenetic thresholds and constructional bans constrain probable morphogenetic transformations and creates PEL, which is a general rule-cliché that formats total disparity of character states and theirs stochastic manifestation in taxonomic units, populations and individuals. Based on Waddington's ideas of creode, S.V. Meyen introduced concepts of intracreode and extracreode. Population meronomy allows to characterize peculiarities of extracreode of a population or a taxonomic unit while studying intracreodes as intraindividual variability by means of phenetical analysis (reductional stage) and phenogenetic synthesis (compositional stage). In this case we estimate not individual variability (plasticity) proper but generalized population or taxonomic epigenetic diversity of intracreode, which in actually becomes an extracreode. Population-meronomic analysis of bilateral compositions of antimere structure elements allows to construct a natural system of structure transformations and thereby to visualize meronomic diversity and transformation paths of meron.

The influence of body size and net diversification rate on molecular evolution during the radiation of animal phyla.

BACKGROUND: Molecular clock dates, which place the origin of animal phyla deep in the Precambrian, have been used to reject the hypothesis of a rapid evolutionary radiation of animal phyla supported by the fossil record. One possible explanation of the discrepancy is the potential for fast substitution rates early in the metazoan radiation. However, concerted rate variation, occurring simultaneously in multiple lineages, cannot be detected by "clock tests", and so another way to explore such variation is to look for correlated changes between rates and other biological factors. Here we investigate two possible causes of fast early rates: change in average body size or diversification rate of deep metazoan lineages. RESULTS: For nine genes for phylogenetically independent comparisons between 50 metazoan phyla, orders, and classes, we find a significant correlation between average body size and rate of molecular evolution of mitochondrial genes. The data also indicate that diversification rate may have a positive effect on rates of mitochondrial molecular evolution. CONCLUSION: If average body sizes were significantly smaller in the early history of the Metazoa, and if rates of diversification were much higher, then it is possible that mitochondrial genes have undergone a slow-down in evolutionary rate, which could affect date estimates made from these genes.

Photonic structures in biology.

Millions of years before we began to manipulate the flow of light using synthetic structures, biological systems were using nanometre-scale architectures to produce striking optical effects. An astonishing variety of natural photonic structures exists: a species of Brittlestar uses photonic elements composed of calcite to collect light, Morpho butterflies use multiple layers of cuticle and air to produce their striking blue colour and some insects use arrays of elements, known as nipple arrays, to reduce reflectivity in their compound eyes. Natural photonic structures are providing inspiration for technological applications.

Unexpected discontinuities in life-history evolution under size-dependent mortality.

In many organisms survival depends on body size. We investigate the implications of size-selective mortality on life-history evolution by introducing and analysing a new and particularly flexible life-history model with the following key features: the lengths of growth and reproductive periods in successive reproductive cycles can vary evolutionarily, the model does not constrain evolution to patterns of either determinate or indeterminate growth, and lifetime number and sizes of broods are the outcomes of evolutionarily optimal life-history decisions. We find that small changes in environmental conditions can lead to abrupt transitions in optimal life histories when size-dependent mortality is sufficiently strong. Such discontinuous switching results from antagonistic selection pressures and occurs between strategies of early maturation with short reproductive periods and late maturation with long reproductive cycles. When mortality is size-selective and the size-independent component is not too high, selection favours prolonged juvenile growth, thereby allowing individuals to reach a mortality refuge at large body size before the onset of reproduction. When either component of mortality is then increased, the mortality refuge first becomes unattractive and eventually closes up altogether, resulting in short juvenile growth and frequent reproduction. Our results suggest a new mechanism for the evolution of life-history dimorphisms.

Developmental constraints in a comparative framework: a test case using variations in phalanx number during amniote evolution.

Constraints are factors that limit evolutionary change. A subset of constraints is developmental, and acts during embryonic development. There is some uncertainty about how to define developmental constraints, and how to formulate them as testable hypotheses. Furthermore, concepts such as constraint-breaking, universal constraints, and forbidden morphologies present some conceptual difficulties. One of our aims is to clarify these issues. After briefly reviewing current classifications of constraint, we define developmental constraints as those affecting morphogenetic processes in ontogeny. They may be generative or selective, although a clear distinction cannot always be drawn. We support the idea that statements about constraints are in fact statements about the relative frequency of particular transformations (where 'transformation' indicates a change from the ancestral condition). An important consequence of this is that the same transformation may be constrained in one developmental or phylogenetic context, but evolutionarily plastic in another. In this paper, we analyse developmental constraints within a phylogenetic framework, building on similar work by previous authors. Our approach is based on the following assumptions from the literature: (1) constraints are identified when there is a discrepancy between the observed frequency of a transformation, and its expected frequency; (2) the 'expected' distribution is derived by examining the phylogenetic distribution of the transformation and its associated selection pressures. Thus, by looking for congruence between these various phylogenetic distribution patterns, we can test hypotheses about constraint. We critically examine this approach using a test case: variation in phalanx-number in the amniote limb.

Comments on the taxonomic status of Ikeda taenioides (Ikeda, 1904) with some amendments in the classification of the phylum Echiura.

Examination of thin sections of trunk wall in an old specimen of Ikeda taneioides from Misaki, Sagami Bay revised previous false information about the wall musculature, actually consisting of outer circular, middle longitudinal, and inner-most oblique layers, like all other echiurans. This finding, together with the reexamination of relevant museum specimens, led to some taxonomic changes. These include that the definition of the genus Ikeda was amended to be a senior synonym of Prashadus; the family Ikedidae was regarded as a junior synonym of the family Echiuridae; and the order Heteromyota, erected virtually for I. taenioides, was abolished. Non-discovery of males and some other features in the amended genus Ikeda were noted with reference to its possible relationship with the family Bonelliidae.

[2 phases of form development realized during microevolution]. / Dve fazy formoobrazovaniia, realizuiushchiesia v khode mikroévoliutsii.

The general "plan" of animal structure evolves due to the changes both, in body proportions and body size. The method allowing to estimate the level of population differentiation according to these two parameters was considered. In the process of population differentiation two phases of form formation can be discerned. On the first stage of microevolution the morphogenesis mainly proceeds by proportion changes. The next stage is characterised primarily by changes of size. The same phase can be observed at intra-population level. The selection directed to the increase in differentiation of individuals according to their proportions.

A novel classification of planar four-bar linkages and its application to the mechanical analysis of animal systems.

A novel classification of planar four-bar linkages is presented based on the systematical variation of one, two or three bar lengths and studying the transmission properties (input-output curves) of the linkages. This classification is better suited to the study of biological systems than the classical Grashof-classification used in engineering as it considers the change of structural elements, in evolution for example, instead of evaluating the possibilities for the rotation of a particular bar. The mechanical features of a wide range of planar linkages in vertebrates, described by various authors, have been included in this classification. Examples are: skull-levation and jaw-protrusion mechanisms in fishes, reptiles and birds, the coral crushing apparatus of parrotfishes, and catapult-mechanisms in feeding pipefishes. Four-bar replacement mechanisms, e.g., crank-slider mechanisms in feeding systems of fishes and cam-mechanisms in mammalian limb-joints, and more complex linkages than four-bar ones, e.g., six-bar linkages and interconnected four-bar linkages in fish feeding mechanisms are also discussed. In this way, an overview is obtained of the applicability of planar linkage theory in animal mechanics to mechanical functioning and the effect of possible variations of bar lengths and working ranges in evolution. Four-bar system analysis often provides a rigorous method of simplifying the study of complex biological mechanisms. The acceptable width-range of necessary and undesired hysteresis ('play') in biological linkages is also discussed.

[The relationship of the lifespan of eukaryotes (animals and plants) to their physical characteristics]. / Sviaz' prodolzhitel'nosti zhizni éukariot (zhivotnykh i rastenii) s nekotorymi ikh fizicheskimi kharakteristikami.

Over a wide range of living species from rotifer to sequoia it was shown that there is positive correlation between species longevity and linear size (r = 0.93, n = 186), as well as between species longevity and mass (r = 0.94, n = 37). Real slope of correlation line longevity on mass may be near 0.27. So, for all studied species exist the general low- the more its mass (or weight, or volume), the longer its life span. It is possible that between mass (or volume) and longevity of living things there is causal relation.

[Eukaryotes devoid of the most important cellular organelles (flagella, Golgi apparatus, mitochondria) and the main task of organellology]. / Eukarioty, lishennye vazhneishikh kletochnykh organell (zhgutikov, apparata Gol'dzhi, mitokhondrii), i glavnaia zadacha organellologii.

Comparative evidence on the lack of three important organelles (flagella, Golgi-complex, mitochondria) in cells and organisms at the cellular level of organization has been summarized for all the four eukaryotic kingdoms--Protista, Fungi, Plantae and Animalia (Metazoa). It is established that in the course of evolution these organelles may undergo the total reduction. There is no cellular organelle to be regarded as universal, indispensable. There are only three main obligatory cell components--the plasmalemma, nucleus and cytoplasm (with applied cytoskeleton, cytomembranes and ribosomes). The reduction of flagella (cilia) is occurring in different taxa independent of the transition of protists from the flagellate type of locomotion to the amoeboid, gliding of metabolizing ones, and in the number of metazoan cells. The members of Protista and Fungi, which line in microaerobic or anaerobic conditions, nearly inevitably lose their mitochondria. The tendency to lose Golgi-complex is demonstrated in protists with parasitic mode of life, especially in combination with anaerobiosis. There is so far no satisfied morphological criterium that could say with certainty whether the lacking of flagella, Golgi complex or mitochondria in the low eukaryotes may be primary or secondary (as the result of reduction). Data on the composition, structure and RNA nucleotide sequences cannot be either the straight evidence. A comparative analysis of these data shows that the ribosomes of the primary eukaryotes were, presumably, of a prokaryotic type. Their eukaryotization was carried out for a long time during the evolution of the low eukaryotes (Protista and Fungi), probably, independently in different phylogenetic lines. It is unknown at what steps and in what main phylogenetic lines the three above mentioned organelles may have appeared. It is proposed to single out a special division of cytology--organellology (organoidology)--as an individual science whose main purpose may be investigation of the origination, evolution and disappearance of organelles.

[The wisdom of the animal body]. / Die Weisheit des Tierkörpers.

In 1932 CANNON described the physiological wisdom of the body. This cannot exist without morphological wisdom. Since morphology is a formative process, both kinds of wisdom depend on the same formative forces. These forces are the forces of consciousness at all levels. Their existence is proved by the fact that they can be eliminated by narcosis. The wisdom of these forces is twofold: Firstly, the wisdom of need sensation which lasts only until the need is satisfied. This is the conscious intelligence of the body which is responsible for restraint in all living beings. Secondly, the wisdom, or better, the prudence of need satisfaction which requires knowledge and appropriate tools. The organs of the body are these tools. Knowledge belongs to the intellect which knows how to handle material. This is achieved in all prehuman species subconsciously and is demonstrated in all structures built by cells and animals. Only the human mind can be unwise and imprudent; but man, being free, is also able to be wise and prudent and so prevent the extinction of the earthly creation.