Shabanov et al. (2014) Ontogenetic strategies of precocity and stuntedity

Shabanov D. A., Korshunov A. V., Kravchenko M. A., Meleshko E. V., Shabanova A. V., Usova E. E. Intrapopulation ontogenetic strategies for early maturity and stunted growth: a case study of tailless amphibians // Bulletin of V. N. Karazin Kharkiv National University, Biology Series. — 2014. — Vol. 22, No. 1126. — pp. 115–124. UDC: (575.826+57.017.64):597.8 Intra-population ontogenetic strategies of early maturity and stunted growth: a case study of tailless amphibians D.A. Shabanov, A.V. Korshunov, M.A. Kravchenko, E.V. Meleshko, A.V. Shabanova, E.E. Usova V.N. Karazin Kharkiv National University (Kharkiv, Ukraine) d.a.shabanov@gmail.com This paper proposes definitions of intrapopulation ontogenetic strategies, considered primarily using the example of tailless amphibians (Bufo bufo and representatives of the Pelophylax esculentus complex). A strategy (in biology) is a hierarchy of priorities manifested in an organism’s complex of adaptations (ecological strategy), its development (ontogenetic strategy), or behavior (behavioral strategy, ethological strategy). An intraspecific strategy is one of the discrete or continuum-based variants of species-specific strategy implementation found among members of a single population. Early maturity is an intrapopulation ontogenetic strategy characterized by a relatively high growth rate, early maturation, an increased number of offspring per reproductive cycle, and a relatively shorter lifespan. Slow growth – an intraspecific ontogenetic strategy characterized by a relatively low growth rate, delayed maturation, a reduced number of offspring per reproductive cycle, and a relatively longer lifespan, resulting in an increase in the number of reproductive cycles reproductive cycles in which an individual can participate. Keywords: strategy, lifespan, fecundity, ontogenesis, early maturity, late maturity, Bufo bufo, Pelophylax esculentus complex. Intra-population ontogenetic strategies of early and late maturity: a case study of tailless amphibians D.A. Shabanov, O.V. Korshunov, M.O. Kravchenko, O.V. Meleshko, G.V. Shabanova, O.E. Usova This paper proposes definitions of the intrapopulation ontogenetic strategies under consideration, primarily using the example of tailless amphibians (Bufo bufo and representatives of the Pelophylax esculentus complex). A strategy (in biology) is a hierarchy of priorities manifested in an organism’s complex of adaptations (ecological strategy), its development (ontogenetic strategy), or behavior (ethological strategy). An intrapopulation strategy is one of the discrete or continuum-based variants of implementing a species-specific strategy found in members of a single population. Early maturity is an intrapopulation ontogenetic strategy characterized by relatively high growth rate, early maturity, a higher number of offspring per reproductive cycle, and a relatively shorter lifespan. Late-maturity is an intraspecific ontogenetic strategy characterized by slow growth, delayed maturity, a reduced number of offspring per reproductive cycle, and a relatively longer lifespan, resulting in an increase in the number of reproductive cycles in which an individual can participate. Keywords: strategy, lifespan, fecundity, ontogenesis, precocity, stunted growth, Bufo bufo, Pelophylax esculentus complex. Intrapopulation developmental strategies of precocity and stunted growth: a case study of anurans D.A. Shabanov, A.V. Korshunov, M.A. Kravchenko, E.V. Meleshko, A.V. Shabanova, E.E. Usova A definition of intrapopulation developmental strategies, discussed primarily using the example of anurans (Bufo bufo and representatives of the Pelophylax esculentus complex), is proposed in this paper. Strategy (in biology) is the hierarchy of priorities manifested in the complex of organism adaptations (environmental strategy), in its development (developmental strategy), or in behavior (behavioral strategy, ethological strategy). Intrapopulation strategy is one of the variants of the realization of species-specific strategies (discrete or integrated into a continuum) found among members of a population. Precocity is an intrapopulation developmental strategy characterized by a relatively high growth rate, early maturation, an increased number of offspring per breeding cycle, and a relatively short lifespan. Stuntedness is an intrapopulation developmental strategy characterized by a relatively low growth rate, delayed puberty, a reduced number of offspring per breeding cycle, and a relatively longer lifespan, which results in an increase in the number of reproductive cycles in which the individual can participate. Keywords: strategy, lifespan, fecundity, ontogeny, precocity, stuntedity, Bufo bufo, Pelophylax esculentus complex. Introduction At the current stage of biological research, the study of ontogenetic strategies is primarily conducted by comparing different species. The very concept of strategy remains rather vague; often, the terms “ontogenetic strategy,” “developmental strategy,” “life strategy,” “adaptive strategy,” “ecological strategy,” “ecological-coenotic strategy,” and others are used as fully or partially interchangeable. This article is devoted to developing a conceptual framework for describing intraspecific diversity in growth rate, fecundity, and lifespan. Here, we will briefly review the history of the formation of ideas about ontogenetic strategies and working definitions of the intraspecific ontogenetic strategies of early maturity and late maturity will be developed. Species-level ecological strategies As noted by M.B. Mirkin and L.G. Naumova (2005), the first analogues of modern concepts of ecological strategies appeared as early as the 19th century. In 1870, the English philosopher Herbert Spencer noted that for any organism, maintaining its own existence and perpetuating itself through offspring are, to a large extent, alternatives. The example cited by Spencer (elephants and mice) sounds quite modern: even today, the comparison of elephants and mice is a common illustration of r- and K-strategiesin mammals. In modern terms, increasing one’s own survival and increasing the number of offspring are in a trade-off relationship—a strong negative correlation, an antagonism (Mirkin, Naumova, 2005). Furthermore, in 1884, the Belgian botanist Julius MacLeod (J. MacLeod) described “proletarians” and “capitalists” among plants. “Proletarians” overwinter in the seed stage, while “capitalists” form massive storage organs by winter: bulbs, tubers, rhizomes, etc. (Hermy, Stieperaete, 1985). A serious study of ecological strategies began with a work published in 1967 by the outstanding American biologists: ecologist Robert MacArthur and evolutionary myrmecologist Edward Wilson (MacArthur, Wilson, 1967). This work established the existence of two types of selection leading to the formation of two distinct ecological strategies; these types of selection and strategies are designated r- and K- by analogy with the parameters appearing in P. Verhulst’s logistic equation dN / dt = rN((K-N) / K), where N is the population size, r is the reproductive potential, or the Malthusian parameter, and K is the environmental carrying capacity, or the Verhulst parameter (Bobylov et al., 2014). As noted by E. Pianka, who played a major role in the development of the concepts under discussion, these strategies correspond to two different types of populations (Pianka, 1981). In opportunistic populations, conditions regularly arise that favor rapidly reproducing organisms. This type of selection is called r-selection. Since reproductive potential is a variable in the logistic equation, a lowercase letter is used to denote it. In equilibrium populations, highly competitive individuals have an advantage. McArthur and Wilson called this type of selection K-selection. Since the carrying capacity in the logistic equation is a constant, an uppercase letter is used to denote it. It is evident that r/K strategies reflect the antagonism noted by Spencer between self-preservation (K-strategy) and reproduction (r-strategy). It must be emphasized that the space of r/K-strategies is a continuum in which no species can be an absolute r- or K-strategist. By comparing the distribution of species along this continuum, one can establish only “more-or-less” relationships (a mouse is an r-strategist only in comparison with an elephant; compared to E. coli, it is a pronounced K-strategist). Concepts of r/K-strategies formed the basis of the life-history evolution concept (review—Begon et al., 1989; Begon et al., 2006). In particular, it further developed the ideas regarding an individual’s reproductive value first proposed by Ronald Fisher (Fisher, 1930). According to this approach, at each stage of the life cycle, an individual’s reproductive value can be represented as the sum of two components: its offspring at that stage and its residual reproductive value, which depends on the individual’s expected survival probability and fertility (Bigon et al., 1989). It is evident that r-strategists maximize their expected number of offspring in the short term (in the limit, over a single reproductive cycle occurring as early as possible), while K-strategists maximize offspring over a sufficiently long lifespan with multiple expected reproductive cycles. Unfortunately, the classic theories of r/K strategies did not propose terminology to describe the intra-population diversity of individuals in terms of their priority for self-preservation versus reproduction. Since the described strategies are the result of corresponding selection, it is evident that individuals within a population differ in the balance of these priorities. From our perspective, this omission (given the authority established by McArthur and Wilson’s approach) led to a delay in describing intraspecific diversity among individuals. In contrast to the two-polar classification of strategies by Mc, a three-pole classification of plants has become widely accepted in botany, independently proposed by L.G. Ramensky (1938) and J. Grime (Grime, 1974). It assumes the existence of three poles. Type C (from the English “competitor”) according to Grime, or “violent” (from the Latin “violent”) according to Ramensky, includes the most competitive species. These are dominant species that determine the character of most plant communities. Type S (from the English “stress-tolerant”) according to Grime, or “patient” (from the Latin “patiens”—patient) according to Ramensky, corresponds to species inhabiting habitats where competition is practically absent. The success of such species is linked to their ability to survive adverse abiotic environmental conditions. Finally, Type R (from the Latin ruderis – weedy) according to Graim, or the explorer (from the Latin explere – to fill) according to Ramensky, includes species adapted to the rapid capture of unused resources. It is evident that the R type (explorers) corresponds to r-strategists according to McArthur and Wilson, while types C and S (violents and patients) are two forms of K-strategists, which differ in the degree of favorable conditions in their characteristic habitats. The advantage of the Ramensky-Graim classification is that it allows for the identification of mixed variants, distinguishing secondary strategies (SR, CR, CS, CRS), which are combinations of primary strategies. At the same time, this classification has a limitation, manifested in the fact that it is applied to the analysis of species strategies (as well as the strategies of populations of the same species in habitats or parts of the range that differ in character). It is worth mentioning the proposal by A.A. Protasov (2009), who added one more strategy to the Ramensky-Graim classification. Type E, extremals, according to Protasov, inhabits extremely unfavorable disturbed habitats. The difference between strategy E and strategy S lies in the fact that strategy E is implemented in disturbed habitats, while its difference from strategy R lies in the fact it is implemented under extremely unfavorable conditions. Without assessing the suitability of this proposal for describing ecological diversity in anthropogenically transformed biogeocenoses, we note that the approach under discussion concerns exclusively species strategies and cannot be used to describing intraspecific diversity. Defining the Concept of Strategy For further discussion, it is necessary to develop a working definition of the concept of “strategy” (from the Greek στρατηγία – the science of successful warfare), both in biology and in its general sense. A search for the meanings of this term in various dictionaries shows that in most cases it is used in a different sense than the one considered in this article: as the art of war, a long-term program of action, a plan, etc. It is clear that a biological (ecological) strategy is not a rigid algorithm, and its selection is not the result of goal-setting. In biological dictionaries, a definition of this term is rare, except for discussions of the concept of ESS, the evolutionarily stable strategy, proposed by J. Maynard Smith (Maynard Smith, Price, 1973). One example of a biological definition of the concept of strategy is as follows: “Strategy [ECOL]. A group of related traits that evolved under the influence of natural selection and solve particular problems encountered by organisms” (Dictionary…, 2003, p.572). This definition emphasizes the adaptive nature of strategies but does not explain exactly what they are. One of the few definitions of this concept we found that reflects characteristics important to our discussion is not biological in nature: “strategy—a set of rules for decision-making…” (Strategic…, 2005). This definition is suitable for conscious human actions and does not apply to biological strategies, in which case there is no one to formulate any rules. Therefore, we propose using the following, most general approach: a strategy is a hierarchy of priorities reflected in actions, which may be constant or situation-dependent. Strategies in human behavior may result from rational planning or the unconscious integration of prior experience. Biological strategies are the result of prior selection. Priorities in biological strategies are, first and foremost, the maximization of an individual’s chances of continuing its life at astage of its ontogenesis or maximizing the number of offspring it will leave at that stage. A strategy (in biology) is a hierarchy of priorities manifested in the organism’s complex of adaptations (ecological strategy), its development (ontogenetic strategy), or its behavior (behavioral strategy, ethological strategy). A strategy can be rigid (unambiguously defined, implementable under any conditions) or flexible (dependent on the environment and the organism’s state). A biological strategy is an evolutionarily developed compromise between divergent selection vectors (priorities). Why can’t organisms be fast-growing, highly productiveand long-lived at the same time? Because these priorities are in a trade-off relationship. Thus, biological strategies are a special case of adaptive compromises according to A.P. Rasnitsyn (2008). If the compromise combinations of evolutionary priorities turn out to be discrete, different strategies are well-distinguished from one another (as in most dioecious organisms, where male and female strategies are distinct). If the compromise turns out to be “fluid,” depending on many variable circumstances, a continuum of possible strategies is formed, the optimum of which is determined by the specific conditions of the habitat or the state of the organism. The strategies of-Arthur and Wilson’s strategies reflect the priority of self-preservation or reproduction, the antagonism between which was noted as early as by Spencer. From our perspective, McArthur and Wilson’s r/K strategies are both autecological and ontogenetic. Ramensky and Graim’s strategies, from this perspective, are synecological. Evolutionarily stable strategies: species-specific or intraspecific? It should be emphasized that the definitions of the concept of strategy in biology known to us refer only to species strategies. In a number of cases, in our opinion, ignoring intraspecific strategies leads to erroneous conclusions. For example, this applies to evolutionarily stable strategies (ESS). They are defined as follows: “An ESS or evolutionarily stable strategy is a strategy such that, if all the members of a population adopt it, no mutant strategy can invade” (Maynard Smith, 1982). It is clear that this definition refers to a species-specific strategy adopted by all individuals in the population. It is generally accepted (see, for example, Markov, 2011) that the ESS concept is analogous to John Nash’s equilibrium in biology, where the strategies of “players” are innate rather than consciously chosen. A Nash equilibrium is a situation in which none of the players can change their strategy without worsening their outcome, provided that the other players do not change their course of action (Nash, 1961). From the perspective of mathematical game theory, as developed by J. Nash, it is not necessary for different players to adopt the same strategy. In contrast, the definition of an ESS stipulates that this strategy must be adopted by a majority of individuals. To demonstrate that this distinction is significant, let us consider a situation discussed by Maynard Smith himself (1981): intra-population competition between dioecious organisms (characterized by the so-called “double male cost”) and parthenogenetic females or hermaphrodites (in which all individuals directly produce offspring). This situation is examined from the perspective of why sexual dimorphism acts as the ESS (species-specific strategy). Is it correct in this case to consider ESS as a characteristic of the majority of individuals in the population? In our opinion, no, and the reason for this is not only that parthenogenetic or hermaphroditic individuals “fall outside” the species-specific strategy. When examining the intraspecific strategies of males and females, one can see that there are situations in which males reproduce more successfully than hermaphrodites. It is precisely this circumstance that is associated with battles between cross-fertilizing hermaphrodites, during which each partner strives to act only in the male role (Shabanov, 2009). Such situations may be the cause of the instability of the hermaphroditism strategy and the spread within the population of the male strategy first, followed by the female strategy. In such a scenario, there is no general species-specific strategy at all. On the other hand, there are likely situations in which it makes no sense to analyze male or female strategies separately and it is rational to consider them as interrelated parts of a single strategy of sexual dimorphism. This implies the existence of a certain hierarchy of strategies. When discussing biological strategies, it is necessary to clearly specify which level is being discussed: species-specific or intraspecific. Definition of the concept of intraspecific strategy As we have seen, theoretical concepts regarding intraspecific diversity of strategies remain largely undeveloped. At the same time, the need to address practical issues in managing artificial and natural populations inevitably required taking into account the differences observed among individuals. The problem of interest to us has been best addressed in applied ichthyology. This is due both to the practical importance of fish populations and to the presence in them of effective recording structures (scales, otoliths) that allow for the determination of the age and growth dynamics of individual organisms. The classification of individuals within a generation into those characterized by rapid or slow growth has become one of the classic methods of ichthyology (Nikolsky, 1965; Mina, Klevezal, 1976). Thus, a number of recent studies have shown that harvests during the exploitation of fish populations (and populations of other groups) lead to changes in their characteristic growth rates (Darimont et al., 2009); at the same time, the growth rates of representatives of practically important species can be controlled through biocenotic interactions (e.g., Persson et al., 2007). As noted above, the main parameters determining the type of strategy are the number of offspring during the current reproductive cycle and the expected lifespan, which influences the probable number of offspring during subsequent cycles. Fish growth rate is closely related to these parameters. Fertility is related to body size, and “it is known that in fish, in some cases, individuals of the same age that differ in growth rate also differ in lifespan: fast-growing individuals live shorter lives than slow-growing ones” (Mina, Klevezal, 1976, p. 12). A recent example of such a relationship is the phenomenon described in the work of D.N. Kutsin: “the adaptive response of the Azov population of the European bullhead to high mortality leads to the formation of a fast-growing, early-maturing form with a shortened life cycle” (Kutsin, 2013, p. 46). Researchers from the group on the population ecology of tailless amphibians at V.N. Karazin Kharkiv National University demonstrated that individuals from populations of common toads ( Bufo bufo L., 1758)at different stages of habitat colonization differ significantly in their growth patterns (Maro et al., 2008). These and other reasons lead us to view the diversity of individuals within a population as a manifestation of their intraspecific strategies, which are similar in nature to the r/K strategies described by MacArthur and Wilson. An analysis of age and growth rate characteristic of members of the hybridogenic complex of green frogs (Pelophylax esculentus complex), conducted using skeletal chronology (Usova, Shabanov, 2009; Usova, 2010a, 2010b, 2014), their heterogeneity in growth rate and lifespan became apparent. The two recorded growth forms of the frogs were previously tentatively designated as fast-growing and long-lived (Usova, 2010b). The first of these forms is characterized by high growth rate, short lifespan, and, likely, high fecundity (a relatively large number of eggs produced by each female during spawning). The second form is characterized by low growth rate, high lifespan, and, most likely, lower fecundity (a smaller number of eggs per spawning event). The bimodality of the distribution of body length in homogeneous samples of female frogs (Meleshko et al., 2014 and other data), as well as the division of egg clutches into “large” (more than 2,000 eggs) and “small” (fewer than 1,500 eggs) (Tsiklauri, Gryaznova, 2012). The results of studies on common toads from habitats at different stages of colonization (Maro et al., 2008; Shabanov, 2012) allow us to add another characteristic to the described syndromes. Fast-growing and highly prolific toads are likely to be early maturing, while slow-growing and less prolific ones mature later. The link between a high growth rate and a relatively large number of offspring in tailless amphibians has also been established in a number of Western European studies (Lardner, Loman, 2003; Castellano et al., 2004). The first of these publications highlights the existence of two distinct reproductive strategies in green toads (Bufo viridis Laur., 1758). Based on the above, we consider it necessary to propose the concept of an intraspecific strategy. An intrapopulation strategy is one of the discrete or continuum-based variants of a species-specific strategy found among members of a single population (or a similar biosystem, e.g., – a hemiclonal population system of a hybridogenic species complex; Shabanov, Litvinchuk, 2010). When studying intrapopulation strategies, it is important to distinguish their manifestations from random deviations in the ratios of the priorities under consideration. Even in a homogeneous population, individuals that are more or less viable and more or less fertile are inevitably found. The most important criterion indicating that the observed differences reflect intrapopulation strategies is the bimodality (or multimodality) of the observed distributions of the parameters under consideration, characteristic of individuals inhabiting an environment that does not impose such a distribution. This approach follows from the multivariate central limit theorem (Ayvazyan et al., 1983): a parameter influenced by a set of factors comparable in strength assumes a distribution close to a multivariate normal distribution. Bi- or multimodality of the distribution of individuals homogeneous in age, location, and collection method reflects the fact that the variable under study is influenced by at least one significantly more powerful factor. If this factor results from the preferential selection of one of several alternative priorities, the observed diversity can be regarded as a reflection of intraspecific strategies. For example, the height distribution of healthy adults from a single population is typically bimodal (Shabanov, 2006); the factor that divides it into two parts is sex (which can also be viewed as an intraspecies strategy). Another significant circumstance indicating that bior multimodality of the intra-population distribution of individuals according to parameters reflecting their adaptation strategies is a reflection of the diversity of their strategies is that the variable traits do not vary independently, but form a specific syndrome. Intrapopulation strategies of early maturity and stunted growth As noted above, available empirical data indicate that individuals from two different groups of tailless amphibians (Bufo bufo and Pelophylax esculentus complex) exhibit intrapopulation diversity, differing in a complex of parameters related to trade-offs: growth rate, time to maturity, fecundity, and lifespan. Since the traits under consideration are not independent but form a specific syndrome, we regard them as manifestations of intrapopulation strategies and consider it appropriate to use specific terms to denote them. As a preliminary solution, we propose using the terms precocity and stuntedity. Precocity is an intraspecific ontogenetic strategy characterized by a relatively high growth rate, early maturation, an increased number of offspring per reproductive cycle, and a relatively shorter lifespan. Stunted growth is an intraspecific ontogenetic strategy characterized by a relatively low growth rate, delayed maturation, a reduced number of offspring per reproductive cycle, and a relatively longer lifespan, resulting in an increase in the number of reproductive cycles in which an individual can participate. These strategies are ontogenetic, as they reflect a trade-off between self-maintenance and reproduction, reflected in the course of individual development. These strategies are intrapopulation, as they reflect the diversity of individuals within populations or, in the case of green frog hybrids, hemiclonal population systems (Shabanov, Litvinchuk, 2010). The question of how widespread these strategies are remains open. It can be assumed that the aforementioned strategies of tailless amphibians are homologous to those of fish, particular, the aforementioned stunted growth of the Azov ramshorn snail (Kutsin, 2013). A remarkable parallelism is observed between these ontogenetic strategies and patterns of individual development observed in mammals. For example, a recent article by Australian authors (Adler, Bonduriansky, 2014) highlights the adaptive nature of the mammalian response to malnutrition. It consists of slowed growth, reduced fertility, and increased lifespan. Ultimately, this leads to an increase in an individual’s chances of surviving “the end of the lean period” and improved conditions. It should be emphasized that the increase in lifespan in response to restrictive (low-calorie) nutrition, discovered in 1935 by Clive McCay (McCay et al., 1935), has been studied for several decades by the School of Experimental Gerontology at the Institute of Biology of V.N. Karazin Kharkiv National University (Bozhkov, Nikitchenko, 2013). The authors of this article suggest that in all the cases listed, we are dealing with manifestations of a slow-growth strategy, homologous in amphibians, fish, and mammals. This suggests that the mechanisms influencing the switching between early maturity and slow-growth strategies can be viewed as factors that effectively increase productivity or extend lifespan. A number of issues remain outside the scope of this article, requiring specialized research. Let us list some of them. It remains unclear whether an individual can change the type of its intraspecific strategy during its lifetime. For example, data obtained from a study of body size forms (likely corresponding to intraspecific ontogenetic strategies) in Arctic char (Alekseyev et al., 2009) support this possibility. The heritability of the choice of a particular intrapopulation ontogenetic strategy remains unclear, as does the influence of specific environmental factors on this choice. It remains unknown at which stage of ontogenesis in tailless amphibians the determination of a particular strategy occurs. The results of a number of studies (e.g., Fominykh, Lyapkov, 2011) support the hypothesis that the choice of a specific type of ontogenetic strategy occurs as early as the larval stage. In accordance with a previously proposed hypothesis (Maro et al., 2008), in Bufo bufo the density of tadpoles in the water body where their larval development took place plays the role of such a switch. The primary driving factor facilitating the transition to the stunted growth strategy may be either food scarcity (acting as an analogue of dietary restriction) or other factors, such as the regulation of development by water metabolites present in the water body (Schwartz, 1972). The authors are convinced that the study of intraspecific ontogenetic strategies in tailless amphibians is a pressing task. This article should be viewed as a contribution to the development of the conceptual framework necessary for such a study. The authors express their deep gratitude to A.P. Rasnitsyn for his criticism and discussion of the ideas and definitions presented in the article. Bibliography Aivazyan S.A., Enyukov I.S., Meshalkin L.D. Applied Statistics: Fundamentals of Modeling and Primary Data Processing. – Moscow: Finance and Statistics, 1983. – 471 pp. Bigon M., Harper J., Townsend K. Ecology. Individuals, Populations, and Communities: in 2 vols. Vol. 2. – Moscow: Mir, 1989. – 477 pp. Bobylev Yu.P., Brigadirenko V.V., Bulakhov V.L., et al. Ecology. – Kharkiv: Folio, 2014. – 672 pp. Kutsin D.N. Structure of the spawning stock and growth rates of the Azov roach ( Rutilus rutilus heckeli Nordmann, 1840) in the eastern part of the Taganrog Gulf // Bulletin of Astrakhan State Technical University. Series: Fisheries, 2013. – No. 3. – pp. 46–54. Markov A.V. Introduction to the Life Sciences. Lecture Course. Joint Bachelor’s Program of the Higher School of Economics and the Zaporizhzhia School of Economics. – 2011. Maro A.N., Shabanova A.V., Shabanov D.A. Can the developmental conditions of Bufo bufo tadpoles determine the rates of postmetamorphic growth and maturation in toads? // Issues in Herpetology. Proceedings of the 3rd Congress of the A.M. Nikolsky Herpetological Society. – St. Petersburg, 2008. – pp. 274–280. Mina M.V., Klevesal G.A. Animal Growth. – Moscow: Nauka, 1976. – 291 pp. Mirkin M.B., Naumova L.G. Fundamentals of General Ecology. Moscow: Universitetskaya Kniga, 2005. – 240 pp. Nikolsky G.V. The Theory of Fish Stock Dynamics as the Biological Basis for the Rational Exploitation and Reproduction of Fish Resources. – Moscow: Nauka, 1965. – 379 pp. Maynard Smith, J. The Evolution of Sexual Reproduction. – Moscow: Mir, 1981. – 272 pp. Nash, J. Non-Cooperative Games / Matrix Games. – Moscow: Fizmatgiz, 1961. – pp. 205–221. Pianka, E. Evolutionary Ecology. – Moscow: Mir, 1981. – 400 pp. Protasov, A.A. The Concept of Life Strategies: On the Significance of Species in Communities // Marine Ecological Journal. – 2009. – No. 1, Vol. VIII. – pp. 5–16. Ramensky L.G. Introduction to Comprehensive Soil-Botanical Land Survey. – Moscow: Selkhozgiz, 1938. – 620 pp. Rasnitsyn A.P. Theoretical Foundations of Evolutionary Biology // Introduction to Paleoentomology. – Moscow: KMK Scientific Publications Association, 2008. – pp. 6–79. Strategic Management / Edited by A.N. Petrov. – St. Petersburg: Piter, 2005. – 496 pp. Usova E.E. Determination of natural mortality in sexually mature green frogs (Pelophylax esculentus complex; Amphibia, Ranidae) using skeletal chronology // Bulletin of V.N. Karazin Kharkiv National University. Series: Biology. – 2010a. – Issue 12, No. 920. – pp. 104–110. Usova E.E. Skeletochronological study of the lifespan and growth dynamics of representatives of the Pelophylax esculentus complex: recording differences between fast-growing and long-lived frogs // Biodiversity and Sustainable Development. Abstracts of the International Scientific and Practical Conference. – Simferopol: KNC, 2010b. – pp. 121–124. Usova E.E., Shabanov D.A. On the optimization of methods for retrospective assessment of body size dynamics in members of the Pelophylax esculentus complex (Amphibia, Ranidae) using skeletal chronology // Zoocenosis-2009. Biodiversity and the role of animals in ecosystems. – Dnipropetrovsk: DNU, 2009. – Pp. 278–280. Usova E.E. Age and growth rate of green frogs ( Pelophylax esculentus complex) in the Lower Dobritsky Pond (Zmiyevsky District, Kharkiv Region) // Bulletin of V.N. Karazin Kharkiv National University. Series: Biology. – 2014. – Vol. 20, No. 1100. – pp. 204–212. Fominykh A.S., Lyapkov S.M. Formation of new life cycle characteristics of the marsh frog (Rana ridibunda) in a heated pond // Journal of General Biology. – 2011. – Vol. 72, No. 6. – pp. 403–421. Tsiklauri O.Yu., Gryaznova A.V. The dependence of female green frog fertility on their size // “Biology: From Molecules to the Biosphere”. Proceedings of the VII International Conference of Young Scientists. – Kharkiv: T.M. Shapovalova, 2012. – p. 285. Shabanov D. Lies, brazen lies, and… // Kompyuterra. – Moscow, 2006. – No. 25–26 (645–646). – pp. 54–59. Shabanov, D. A. Why Sexually Dimorphic Organisms Displace Cross-Fertilizing Hermaphrodites: Sexual Dimorphism as a Nash Equilibrium // Proceedings Proceedings of the International Scientific Conference Dedicated to the 80th Anniversary of the Birth of Prof. A.P. Krapivny. – Kharkiv: V.N. Karazin Kharkiv National University, 2009. – pp. 38–49. Shabanov D. Toads. Early-maturing or slow-growing // KompyuterraOnline, 2012. Shabanov D.A., Litvinchuk S.N. Green frogs: a life without rules or a special mode of evolution? // Nature. – 2010. – No. 3 (1135). – pp. 29–36. Shvarts S.S. Metabolic regulation of animal growth and development at the population and organismal levels // Izvestiya AN. USSR. Biol. Ser. – 1972. – No. 6. – Pp. 142–151. Adler M.A., Bonduriansky R. Why do the well-fed appear to die young? // BioEssays. – 2014. – Vol. 36, Iss. 5. – P. 439–450. Alekseyev S.S., Mina M.V., Smirina T.M., Sokolov A.A. Late ontogeny growth acceleration and size-form transformations in the Transbaikal Arctic charr, Salvelinus alpinus complex: evidence from fin ray cross-section growth layers // Environ. Biol. Fish. – 2009. – Vol. 86. – P. 487–505. Begon M., Townsend C.R., Harper J.L. Ecology. From individuals to ecosystems. – Malden–Oxford–Victoria: Blackwell Publishing, 2006. – 738 pp. Bozhkov A.I., Nikitchenko Yu.V. Caloric restriction diet induces specific epigenotypes associated with life span extension // Journal of Nutritional Therapeutics. – 2013. – Vol. 2, No. 1. – pp. 30–39. Castellano S., Cucco M., Giacoma C. Reproductive investment of female green toads (Bufo viridis) // Copeia. – 2004. – No. 3. – P. 659–664. Darimont C.T., Carlson S.M., Kinnison M.T. et al. Human predators outpace other agents of trait change in the wild // PNAS. – 2009. – Vol. 106, No. 3. – pp. 952–954. Dictionary of Bioscience: Second Edition. – McGraw-Hill, 2003. – 662 pp. Fisher R.A. The Genetical Theory of Natural Selection. – Oxford: Clarendon Press, 1930. – 272 pp. Grime J.P. Vegetation classification by reference to strategies // Nature. – 1974. – Vol. 250. – P. 26–31. Hermy M., Stieperaete H. Capitalists and proletarians (MacLeod, 1884): an early theory of plant strategies // Oikos. – 1985. – Vol. 44. No. 2. – P. 364–366. Lardner B., Loman J. Growth or reproduction? Resource allocation by female frogs Rana temporaria // Oecologia. – 2003. – No. 442. – P. 541–546. MacArthur R.H., Wilson E.O. The theory of island biogeography. – Princeton University Press, 1967. – 224 pp. Maynard Smith J. Evolution and the theory of games. – Cambridge University Press, 1982. – 224 pp. Maynard Smith J., Price G.R. The logic of animal conflict // Nature. – 1973. – Vol. 246. – pp. 15–18. McCay C.M., Crowell M.F., Maynard L.A. The effect of retarded growth upon the length of life span and upon the ultimate body size // J. Nutr. – 1935. – Vol. 10. – pp. 63–79. Meleshko O.V., Korshunov O.V., Shabanov D.A. The study of three hemiclonal population systems of the Pelophylax esculentus complex from the Seversko-Donetskiy center of green frog diversity // Bulletin of V.N. Karazin Kharkiv National University. Biology Series. – 2014. – Issue 20, No. 1100. – pp. 153–158. Persson L., Amundsen P.-A., De Roos A. M. et al. Culling prey promotes predator recovery – alternative states in a whole-lake experiment // Science. – 2007. – Vol. 316. – P. 1743–1746. ________________________________________ Submitted by: O.P. Rasnitsyn / Presented by: A.P. Rasnitsyn Reviewer: L.I. Vorobyova Received: 10.09.2014