A Teaching Model of the Principles of Adaptive Radiation

Defnition of the term adaptive zone (AZ) is amended. The Petersen-type communities (PC) are not communities in every sense of the word. They are just the areas within which the same species prevail in their abundance. An accounting gear used for identifcation of PC must be suited for catching of the most abundant species. All dominant species must be represented in the lists, regardless of whether they are seasonal or permanent components of population. Only one factor (either number of individuals or biomass) has to be used for species abundance comparison. For recognition and naming of several PC, the same number of the dominant and subdominant species should be used. Under the abovementioned conditions, if this number is equal to 1 — this method selects nothing more than AZ, which are the elementary PC. The fundamental ecological niche (EN) of a species includes its realized AZ — the real space actually coincides with its geographical range (GR). The GR is situated inside the EN, and the realized AZ is a part of GR. The GR (and sometimes EN) of different species can be partially or fully overlapped, but their AZ cannot be overlapped. Each AZ is compliant with a certain species, but not each species is compliant with AZ. AZ are available to the most dominant species and the size of AZ may serve as one of simple measures of the species capability for survival or success in their struggle for existence, and corresponds to portion of total ecological capacity of the environment used by the species. The interiors of the species GR may contain from zero to several AZ, both of this and other species. The interiors of the species AZ also contain parts of GR of other species having similar requirements to the environment (prey, predators, parasites, competitors, symbionts, and other biotic habitat factors). Potential AZ may be located both inside and outside the real GR of a species, but only within its fundamental GR. The potential AZ can be realized by changing the environmental conditions or passing through existing barriers of distribution. Transformation of potential AZ into a realized one can cause an ecological catastrophe if it breaks the existing balance and leads to signifcant redistribution of the shares of total ecological capacity available for species. But even signifcant changes in the ratios of GR and AZ of species will not cause catastrophic consequences in conditions of abundant vital resources, if ecological capacity of the environment is not flled and packing density of EN is low. Changes in the environment, as well as ontogenetic, migratory, succession and evolutionary processes cause changes in ratio of abundance between different species, including mass ones, that leads to variability of their AZ. Number, sizes, shapes, location of the AZ change progressively, both on the actual and geological time scales, and cyclically in accordance with circadian, seasonal and perennial rhythms. Therefore AZ, as well as GR, EN and communities, should be studied in dynamics and in connection with changes in the environment. Defnitions of the main terms are presented in a Supplement.

In discussions of the major features of evolution, Simpson (1953) applied population genetic models to the interpretation of the fossil record. Most population genetics theory concentrates on details of the genetic system, such as gene frequencies and recombination rates, which cannot be directly observed or inferred from measurements on polygenic characters. Analysis of phenotypic data, particularly fossil material, requires models which are framed as much as possible in phenotypic terms. Starting from a simple formula of quantitative genetics, the methods of population genetics are used here to make a theory of the evolution of the average phenotype in a population by natural selection and random genetic drift. By analogy with Wright's (1931) adaptive topography for genotypes, Simpson (1953) proposed the concept of adaptive zones for phenotypes. This is an intuitive method of visualizing the dynamics of phenotypic evolution in terms of the degree of adaptation of the various phenotypes in a population, it usually being thought that natural selection increases adaptation. Such qualitative ideas are used by most evolutionary biologists and the notion of adaptive zones is popular among paleontologists. In the present paper, the concept of adaptive zones is clarified by the construction of an adaptive topography for the average phenotype in a population. This shows that with constant fitnesses the average phenotype evolves toward the nearest adaptive zone in the phenotype space. But if fitnesses are frequency-dependent the average phenotype may evolve away from an adaptive zone. A method is developed for estimating the minimum selective mortality necessary to produce an observed rate of evolution. In examples of the evolution of tooth characters in Tertiary mammals, these minimum selective mortalities are found to be exceedingly small. In his paper on the measurement of rates of evolution, Haldane (1949) stated that slowness of the rate of change makes it clear that agencies other than natural selection cannot be neglected because they are extremely slow by laboratory standards or even undetectable during a human lifetime. He briefly discussed mutation pressure. Random genetic drift due to finite population size is another such agency. The relative importance of natural selection and random genetic drift has been debated since Wright (1931, 1932) proposed that evolution is a stochastic process. Fisher (1958), for example, believed that random genetic drift is insignificant in relation to natural selection. The debate continues today at a more biochemical level (Lewontin, 1974). In order to objectively evaluate the role of random genetic drift in macro-evolutionary events, it is necessary to use mathematical models to determine the rate of evolution which can occur by repeated samplings of genetic material in a finite population. This paper presents a statistical test for the hypothesis of evolution by random genetic drift, contingent on the effective population size. In examples from the fossil record, it is found that rates of evolution equal to or greater than those observed have a significant probability of occurring by random genetic drift

Reduced fertility in men of reproductive age due to the multi-stage nature, duration, and increased vulnerability of spermatogenesis to effects of environmental factors, primarily chemical and physical ones, is a pressing problem of hygiene and preventive medicine. To identify key areas of development and improvement of the methodology for solving this scientific problem, first of all, it is necessary to systematize knowledge in the field of studying patterns and characteristics of effects produced by environmental exposures on reproductive potential.In this review there are reflected hygienic aspects of effects produced by chemical and physical factors on reproductive health in men, which have been presented in scientific practice over the last twenty five years. The subject of this review was materials found in Russian and international scientometric databases (eLIBRARY, PubMed, Google Scholar, Web of Science, Scopus) and scientific societies and associations of the Russian Federation containing information on peculiar effects produced by chemical and physical environmental factors on reproductive health (160 reports). By now, direct and indirect effects produced by chemical and physical factors on male reproductive health have been established, characterized by morphological and functional disorders of the reproductive system itself or indirect induction of a cascade of oxidative, inflammatory, and other in the body, the pathogenetic mechanisms of which can disrupt the reproductive function at various levels of its regulation through the endocrine, immune, nervous, cardiovascular, and other systems. Despite the existing general scientific achievements in this research area, difficulties and limitations have been identified as regards effects on fertility produced not only by chemical and physical factors or their combined effects but also lifestyle, bad habits, infectious and chronic diseases. This complicates the process of substantiating the true determinant. Systematization of patterns and identification of peculiar direct and indirect influence of environmental factors, primarily chemical and physical ones, on reproductive health provides a more detailed insight into pathogenetic mechanisms of their impact and allows increasing effectiveness of early diagnosis and targeted correction of identified male fertility disorders. This is critically important for maintaining and strengthening reproductive health of the country’s population and ensuring sustainable demographic development of the state.Contribution: Zemlyanova M.A. — study design and editing the text; Koldibekova J.V. — data collection and analysis, writing the text; Kamenskikh D.M. — data collection and analysis, writing the text. All authors are responsible for the integrity of all parts of the manuscript and approval of the manuscript final version.Conflict of interest. The authors declare no conflict of interest.Funding. The study had no sponsorship.Received: September 21, 2025 / Accepted: October 15, 2025 / Published: November 14, 2025

A place for behavior in ecological epigenetics

Analyzing the pattern and causes of phenotypic and genetic variation within and among populations might help to understand life history variability in plants, and to predict their responses to changing environmental conditions. Here we compare phenotypic variation and genetic diversity of the widespread herb Plantago coronopus across Europe, and evaluate their relationship with environmental and geographical factors. Genetic diversity was estimated in 18 populations from molecular markers with AFLP. Phenotypic variation was measured in a subset of 11 populations on six life history traits (plant size, plant growth, fecundity, seed mass, mucilage production and ratio between two functionally different seed morphs). To account for ecological and geographical correlates, we estimated variability in local temperature, precipitation and intraspecific competition, and accounted for the central vs. peripheral position of populations. Phenotypic variation and genetic diversity were not significantly correlated within populations throughout the species' range. Phenotypic variation was positively linked to precipitation variability, whereas genetic diversity was correlated with the position of populations, suggesting that both types of variation are shaped by different processes. Precipitation seems to have acted as a selective agent for variation within populations in most life history traits, whereas the species' post‐glacial demographic history has likely reduced genetic diversity in northern peripheral populations with respect to central ones. The positive association between precipitation variability and phenotypic variation also suggests that plant populations may have higher adaptive potential in ecologically variable rather than stable environments. Our study offers an additional criterion when predicting the future performance of species under environmental changes.

Tolerance to herbivory (the degree to which plants maintain fitness after damage) is a key component of plant defense, so understanding how natural selection and evolutionary constraints act on tolerance traits is important to general theories of plant-herbivore interactions. These factors may be affected by plant competition, which often interacts with damage to influence trait expression and fitness. However, few studies have manipulated competitor density to examine the evolutionary effects of competition on tolerance. In this study, we tested whether intraspecific competition affects four aspects of the evolution of tolerance to herbivory in the perennial plant Solanum carolinense: phenotypic expression, expression of genetic variation, the adaptive value of tolerance, and costs of tolerance. We manipulated insect damage and intraspecific competition for clonal lines of S. carolinense in a greenhouse experiment, and measured tolerance in terms of sexual and asexual fitness components. Compared to plants growing at low density, plants growing at high density had greater expression of and genetic variation in tolerance, and experienced greater fitness benefits from tolerance when damaged. Tolerance was not costly for plants growing at either density, and only plants growing at low density benefited from tolerance when undamaged, perhaps due to greater intrinsic growth rates of more tolerant genotypes. These results suggest that competition is likely to facilitate the evolution of tolerance in S. carolinense, and perhaps in other plants that regularly experience competition, while spatio-temporal variation in density may maintain genetic variation in tolerance.

Phenotypic Plasticity

Towards an evolutionary ecology of sexual traits

Site-specific adaptation by natural selection. A case study with lentil.

Assessment of effects produced by physical and chemical occupational factors on changes in the relative telomere length (RTL) in workers is a promising trend in contemporary research. It can be used as a marker of not only ageing but also intensity of oxidative stress and chronic inflammation. Simulation of such effects in experiments on laboratory ICR mice and Wistar rats enriches our knowledge on the subject. In this study, we were interested in performing comparative assessment of isolated effects produced by physical and chemical factors on the relative telomere length of laboratory animals in a model experiment. The study involved using laboratory animals (mice, n = 65; rats, n = 65) divided into the experiment (total vibration, noise and a mixture of aromatic hydrocarbons) and the control groups. Animals in the control group were intact. Exposure to chemical and physical factors was simulated in a model animal experiment. The relative telomere length was established using the quantitative real-time polymerase chain reaction. The experimental data were analyzed by non-parametric analysis techniques in Statistica 10 software package. Intergroup differences were estimated using the Mann – Whitney test. Critical significance in testing of statistical hypotheses was taken below 0.05. Physical and chemical factors had the greatest influence on RLT shortening in the experimental animals relative to the control (intact animals). This indicates activation of the accelerated ageing pathways and growing risks of diseases associated with these exposures. The fastest RLT shortening rates were established upon exposure to total vibration and the chemical factor in mice after 30 days in the experiment; rats, after 60 days. The maximum growth in RLT shortening upon exposure to noise was established in mice after 60 days in the experiment; rats, after 180 days. Differences in RLT in comparison with its initial value were lost in mice on the 90th day in the experiment and in rats on the 180th day of the modeled chemical and physical exposure, which may be interpreted as overall ageing of the experiment animals. RLT shortening in biological objects upon long-term exposure to adverse chemical and physical factors gives evidence of accelerated ageing of the biological systems in the body and can create elevated risks of cardiovascular and aging-associated diseases.

On the analysis of sector-related and gender-related stresses at the workplace — An analysis of the AET data bank

Assessment of effects produced by physical and chemical occupational factors on changes in the relative telomere length (RTL) in workers is a promising trend in contemporary research. It can be used as a marker of not only ageing but also intensity of oxidative stress and chronic inflammation. Simulation of such effects in experiments on laboratory ICR mice and Wistar rats enriches our knowledge on the subject. In this study, we were interested in performing comparative assessment of isolated effects produced by physical and chemical factors on the relative telomere length of laboratory animals in a model experiment. The study involved using laboratory animals (mice, n = 65; rats, n = 65) divided into the experiment (total vibration, noise and a mixture of aromatic hydrocarbons) and the control groups. Animals in the control group were intact. Exposure to chemical and physical factors was simulated in a model animal experiment. The relative telomere length was established using the quantitative real-time polymerase chain reaction. The experimental data were analyzed by non-parametric analysis techniques in Statistica 10 software package. Intergroup differences were estimated using the Mann – Whitney test. Critical significance in testing of statistical hypotheses was taken below 0.05. Physical and chemical factors had the greatest influence on RLT shortening in the experimental animals relative to the control (intact animals). This indicates activation of the accelerated ageing pathways and growing risks of diseases associated with these exposures. The fastest RLT shortening rates were established upon exposure to total vibration and the chemical factor in mice after 30 days in the experiment; rats, after 60 days. The maximum growth in RLT shortening upon exposure to noise was established in mice after 60 days in the experiment; rats, after 180 days. Differences in RLT in comparison with its initial value were lost in mice on the 90th day in the experiment and in rats on the 180th day of the modeled chemical and physical exposure, which may be interpreted as overall ageing of the experiment animals. RLT shortening in biological objects upon long-term exposure to adverse chemical and physical factors gives evidence of accelerated ageing of the biological systems in the body and can create elevated risks of cardiovascular and aging-associated diseases.

Intraspecific competition implies interaction among the individuals of a population, so natural selection on genotypic variation in characters related to the competition will necessarily be frequency dependent. Intraspecific antagonistic competition exhibits properties similar to other behavioural interactions between individuals. In exploitative intraspecific competition the interactions among individuals are less direct. Exploitation modifies the abundance of the various limiting resources according to the use of these resources by the individual members of the population. The amount of resource available to an individual is therefore a function of the phenotypes present in the population, through their density and frequency.

Learning from differences: Abiotic determinism of benthic communities in Northern Taiwan

Present study carried out in Gwuatr shrimp culture Site and Gwatr Bay in east of Chabahar city, Sistan and Baluchestan province. In this project five stations including supply channel, drainage channel, valve outlet, estuary of Gwatr and the Gwatr Gulf were selected to determine physical and chemical factors such as temperature, salinity, dissolved oxygen, total phosphorus and total nitrogen and pH. Sampling conducted once during the shrimp culturing period and monthly at other times. The main objective of this study is surveying change in environmental condition because of biological and non-biological effluents of Gwatr shrimp culture site on coastal waters of Chabahar. We observed that there is a significant difference among chemical and physical factors between different stations (ANOVA, P ≤ 0.05). In conclusion although there was no thermal pollution in this site, but extending aquaculture activities increased the average of salinity and pH and pollutant in the drainage channels, so environmental health conditions needs to be controlled and monitored by the environmental experts, otherwise, present status may go to undesirable condition or state of emergency.