Formation Of Population Structure Research Articles

Density of the brown hare (Lepus europaeus Pall.) and selected population indicators

The paper presents the results of research on body weight and the formation of population structures (age and sex) of hares in south-eastern Poland (Lublin Upland) conducted in 2019. 205 hares from four regions were analysed, differing in terms of density, and thus the hunting exploitation of the population in these areas. The obtained results showed that the body weight was determined by the age of the individuals, while sex had no significant effect on this parameter. Despite the significant variability of body weight in individual research areas, no significant differences in this feature between regions of origin were found.The age structure was dominated by adults (over 1 year of age), especially in areas with low population densities. In terms of sex structure, females clearly dominated. It has been shown that the described population structures can have a direct impact on the indicators of reproductive capacity and population continuity. Although the sample size was small in the low-density areas, the calculated indicators suggest that these populations are at serious risk of viability. In areas with higher density indicators, the possibilities of limiting hunting should be considered in order to maintain the level of density that guarantees optimal functioning of the population and its durability.

Nutrient factor-dependent performance of bacterial quorum sensing system during population evolution.

Bacterial quorum sensing (QS) system regulates the production of most costly but sharable extracellular products (public goods) in a growth-phase-dependent manner, and the development of this energy-intensive process is susceptible to environmental changes. However, the role of nutrient factors in dominating the QS-mediated cooperative interaction and intracellular metabolism still remains less understood. Here we studied the performance of QS system by growing Pseudomonas aeruginosa under different nutrient and culture conditions. The results of comparative-transcriptomic analyses revealed that carbon source-limitation was the main factor suppressing the activation of QS system, and a substantial number of public-good-encoding genes were induced when phosphorus is limiting in short-term culture. By contrast, although the QS regulation of P. aeruginosa in all the cultures was generally decreased along with the enrichment of QS-deficient individuals during evolution, limitation of different nutrient factors had discrepant effects in directing the formation of population structure by coordinating the production of public goods and primary metabolism, especially the starch and sucrose metabolism. These findings demonstrate the pleiotropy of QS regulation in balancing the development of cooperative behavior and metabolism, and provide a reference for further understanding the role of QS system in causing persistent infections.

Modeling of Multifactor Taxis in a Predator–Prey System

A model of predator–prey dynamics in a spatially heterogeneous range is considered using a system of two nonlinear equations of the diffusion–advection reaction. The pursuit–evasion activity because of the nonuniform distribution of the predator and the resource is taken into account. A numerical study of the effect of directed migration on the formation of population structures was carried out on the basis of the method of lines and staggered grids. The role of taxis in population growth in the area was analyzed, and migration parameters, which are used for the formation of stationary and oscillatory spatiotemporal patterns, were calculated.

Formation of population structure in aphids and methods of its estimation using the example of Rhopalosiphum padi (Hemiptera: Aphididae) (part 1)

Formation of population structure in aphids and methods of its estimation using the example of Rhopalosiphum padi (Hemiptera: Aphididae) (part 1)

Genetic differentiation between local populations of Ips typographus in the high Tatra Mountains range

ABSTRACTMany studies have addressed the question of dispersal potential of Ips typographus, however the approach of molecular ecology have been used only in a few of them. Moreover, none of them has done it on fine scale of just one mountain range. Molecular analysis using a set of six polymorphic microsatellite markers was applied in this study. Adult beetles of I. typographus collected in 22 localities of the High Tatra Mountains were used for the study of genetic differentiation between rapidly expanded local populations of bark beetles after windstorm calamities in spruce stands. Almost none genetic differentiation among local populations or among larger spatial units has been revealed. Analyses did not indicate isolation of populations by distance or formation of population structure. This suggests high potential of I. typographus to disperse over large distances and even the possibility to overcome high mountains ridges.

Population differentiation in whiskered aukletsAethia pygmaea: do diurnal and nocturnal colonies differ in genetics, morphometry and acoustics?

Despite a great number of empirical studies, the mechanisms of population differentiation and the factors that influence this process, particularly in seabirds, remain insufficiently understood. Here we analyzed population structure in the whiskered auklet Aethia pygmaea, a previously poorly studied alcid species with unusual differentiation in colony attendance rhythms (i.e. diurnal in the Sea of Okhotsk vs nocturnal in the Bering Sea), and examined the influence of it on intraspecific differentiation. For this study, we analyzed morphometric measurements, acoustic variables, mitochondrial control region fragment and five microsatellite loci from nine whiskered auklet colonies spanning the breeding range. Previous research has shown a clinal morphometric variation in this species. We build on this analysis by adding auklets from more colonies, for the first time analyzing vocalizations from different colonies and genetic structure of this species. Our data supports a clinal variation in morphometric and acoustic characters with the largest size and the lowest call frequency in western birds, and the smallest size and highest call frequency in the east. We also found two mitochondrial lineages – whiskered auklets from colonies in the Sea of Okhotsk and the Commander Is. (Bering Sea) and from the Aleutian Is. (Bering Sea), that were presumably formed during Sangamonian interglacial period (115 000–130 000 years ago). Genetic clusters found did not reflect differences in colony attendance rhythms, suggesting that they were shaped by other factors (e.g. differences in predator pressure) and are unlikely to have participated in the formation of population structure. Colony fidelity, mobility of birds, proximity of foraging grounds and location of colonies in relation to seasonal ice pack, seem to be more likely determinants of population differentiation.

Impact of anthropogenic pressure on the formation of population structure and genetic diversity of raccoon dog Nyctereutes procyonoides.

The raccoon dog Nyctereutes procyonoides experienced an active introduction and acclimatization in the European part of Russia followed by its migration to and colonization in the neighboring countries. Eventually, it has spread rapidly into many European countries. N. procyonoides probably invaded Lithuania from the neighboring countries of Belarus and Latvia where the species was introduced. However, the data on genetic diversity and population structure of the raccoon dogs in the recently invaded territories are still scarce. The objectives of this study were to investigate genetic diversity of N. procyonoides in Lithuania after acclimatization, and to assess the impact of anthropogenic pressure on the formation of population structure. A total of 147 N. procyonoides individuals collected from different regions of Lithuania were genotyped using 17 microsatellite markers. The microsatellite analysis of raccoon dogs indicated high levels of genetic diversity within the population. The Bayesian clustering analysis in STRUCTURE identified 4 genetic clusters among sampled raccoon dogs that could not reveal a clear separation between subpopulations. The widespread distribution of raccoon dogs in Lithuania, high level of genetic variation observed within subpopulations, and low level of variation portioned among subpopulations suggest migration and gene flow among locations. The significant correlation between genetic and geographic distances indicated isolation that reflected the distance between locations. The fencing of highways and very intensive traffic could be barriers to gene flow between the western and eastern sampling areas of raccoon dogs.

Smallest-Small-World Cellular Harmony Search for Optimization of Unconstrained Benchmark Problems

We presented a new hybrid method that combines cellular harmony search algorithms with the Smallest-Small-World theory. A harmony search (HS) algorithm is based on musical performance processes that occur when a musician searches for a better state of harmony. Harmony search has successfully been applied to a wide variety of practical optimization problems. Most of the previous researches have sought to improve the performance of the HS algorithm by changing the pitch adjusting rate and harmony memory considering rate. However, there has been a lack of studies to improve the performance of the algorithm by the formation of population structures. Therefore, we proposed an improved HS algorithm that uses the cellular automata formation and the topological structure of Smallest-Small-World network. The improved HS algorithm has a high clustering coefficient and a short characteristic path length, having good exploration and exploitation efficiencies. Nine benchmark functions were applied to evaluate the performance of the proposed algorithm. Unlike the existing improved HS algorithm, the proposed algorithm is expected to have improved algorithmic efficiency from the formation of the population structure.

Random amplified polymorphic DNA analysis of southern brown bandicoot (Isoodon obesulus) populations in Western Australia reveals genetic differentiation related to environmental variables.

Random amplified polymorphic DNA (RAPD) markers were used to analyse genetic variation within and between populations of Isoodon obesulus in Western Australia. Genetically controlled geographical variation in body size associated with habitat type and rainfall exists in this species, raising the question of whether local conditions may influence gene flow in I. obesulus. The RAPD markers displayed substantial genetic variation, with all animals possessing unique RAPD phenotypes over 39 polymorphic bands produced by three primers. Significant geographical subdivision was apparent (PhiST = 0.208) with southwest locations being divergent from all others, despite there being no physical barriers to gene flow. The pattern of subdivision was unrelated to physical distance between the locations, but was related to both annual rainfall and habitat type. Therefore, the most reasonable explanation for this pattern of subdivision appears to be that gene flow is restricted by selection against migrants between local populations with substantially different habitat type or rainfall. Restriction of gene flow through selection against migrants is rarely investigated, and the results of this study suggest that the importance of this process in the formation of population structure may be underestimated.