Genetic demography of the Kuznetsk Basin population: changes in marriage assortativeness with respect to ethnicity and age in the Belovo city population with time

A genetic demographic study has been performed in the city of Belovo with the use of the data on marriages contracted there in 1970 and 1994-1999. Marriage assortativeness with respect to age has been found to be the strongest and remain unchanged during the lifetime of one generation (r = 0.730 in 1970 and r = 0.801 in 1994-1999). Monoethnic marriages were substantially more frequent than interethnic ones in the Belovo population during the period studied, although the ethnic marriage assortativeness considerably decreased (K = 0.386 in 1970 and K = 0.141 in 1994-1999). Panmixia has been observed in the Russian population of Belovo. Other Eastern Slavs (Ukrainians and Belarussians) are characterized by negative marriage assortativeness and panmixia; positive marriage assortativeness has been found in other ethnic groups.     

Genetic Demography of Ukrainian Urban Populations in the 1990s: Ethnicity and Birthplaces of Migrants to the Poltava Population

Analysis of the birthplaces and ethnicity of males and females contracting marriages in the city of Poltava in 1960, 1985, and 1995 revealed a trend towards return of Ukrainians from various regions of the former Soviet Union to their places of origin. In the migration flow, Russians were gradually substituted by Ukrainians, and the total proportion of Slavs increased. The isolation by distance (b) decreased from 0.00122 to 0.00075 in the period from 1960 to 1985 and then increased to 0.00098 by 1995. Positive association was found between the parent–offspring distance and marriage distance (the correlation coefficient r = 0.65–0.75).     

Genetic Demographic Analysis of Western Ukrainian Populations: The Marriage Structure of Populations from the Khmel'nitskii Oblast with Respect to Ethnicity and Birthplace

Ukrainians account for 85 and 91% of the populations of the city of Khmel'nitskii and the town of Starokonstantinov (Khmel'nitskii oblast, western Ukraine), respectively, and for 97% of the rural population of the Khmel'nitskii oblast. The proportions of Russians in the urban and rural populations of the Khmel'nitskii oblast are 7–10 and 1%, respectively. Between 1960 and 1995–1998, the proportions of Ukrainians in all populations studied increased and the proportion of interethnic marriages steadily decreased. The marriage association coefficient (K) with respect to ethnicity varied from 0.35 to 0.76 in different years. The highest assortative marriage indices (A) with respect to ethnicity were 75–98 and 71–84% in Ukrainians and Jews, respectively. The migration coefficient was 0.58–0.77. Western Ukrainian populations differ from eastern Ukrainian ones in a steadily decreasing outbreeding component.     

Genetic Differentiation of the Tuva Population with Respect to the AluInsertions

Polymorphism of three rural populations of the Tuva Republic was examined using a set of five autosomal Aluinsertions at the ACE, PLAT, PV92, APOA1,and F13Bloci. The allele frequency distribution patterns revealed in Tuvinians were typical to Mongoloid populations of Asia and were characterized by relatively high frequency of the Alu-repeat insertion at the PV92and F13Bloci along with relatively low insertion frequency at the APOA1locus. With respect to the test systems used, Tuvinian populations examined displayed high levels of genetic diversity. The mean expected heterozygosity values in the populations of Kungurtug, Toora-Khem, and Teeli were 0.433, 0.407, and 0.437, respectively. The level of genetic diversity in the pooled Tuvinian sample was 0.432. The coefficient of genetic differentiation in the three populations studied was 1.4% pointing to relatively low level of genetic subdivision of the indigenous Tuvinian populations. However, estimates of genetic differentiation of the Tuvinian gene pool made by use of the Alu-repeat system were higher compared to those performed using classical protein systems, mtDNA, or Y-chromosomal haplotypes. Even though Tuvinian populations were characterized by common gene pool, some features specific to Western Tuvinian population could be distinguished. These features could be associated with higher contribution of the Caucasian component to the gene pool of this population. Phylogenetic analysis demonstrated close genetic relationships between the Tuvinian and Altaic ethnic populations.     

Genetic Demographic Structure of the Belgorod Population: Age,Ethnicity, Education,and Occupation

Data from marriage records of the city of Belgorod for 1960, 1985, and 1995 have been used to determine some parameters of population structure in this city. The coefficients of correlation with respect to age of marriage between spouses in the couples contracting marriages in these years were 0.74, 0.62, and 0.80, respectively. Women of reproductively unfavorable age (under 20 or over 30 years) accounted for 5.5, 0.83, and 19% of all women contracting marriages in these years, respectively. The proportions of interethnic marriages in these years were 16.9, 14.9, and 15.6%, respectively. The percentage of Slavs decreased from 99 to 97% during the 35 years studied, whereas the proportion of Russians insignificantly increased (from 90.4 to 91.4%). The proportion of Caucasian ethnic groups increased by six time (from 0.3 to 1.8%), and that of other non-Slavic ethnic groups increased by almost two times (from 0.7 to 1.2%). The marriage convergence (K) with respect to ethnicity (0.095, 0.106, and 0.090 in 1960, 1985, and 1995, respectively) was lower than that with respect to education (0.296 and 0.350 in 1985 and 1995, respectively) or occupation (0.212 and 0.231 in 1985 and 1995, respectively). The maximum coefficients of ethnically, educationally, and occupationally assortative marriage have been found, respectively, in ethnic minority groups (A′ = 20%); in persons with higher and primary education (A′ = 37.5 and 49.9%, respectively); and in the military officers/soldiers, engineers, healthcare professionals, and researchers (the respective A′ values are 65.6, 32.2, 31.5, and 39.8%).__________Translated from Genetika, Vol. 41, No. 6, 2005, pp. 823–829.Original Russian Text Copyright © 2005 by Atramentova, Filiptsova.     

Medical Genetic Study of the Rostov Oblast Population: Changes in Reproductive Parameters with Time

Changes in vital statistics and Crow's indices during the past 50 years have been studied on the basis of answers to 2165 questionnaires divided into five groups according to the age of women surveyed.     

Genetic Demographic Structure of the Lugansk (Ukraine) Population: Age,Ethnicity, Education,and Occupation

Data from marriage records from registry office archives of 1960, 1985, 1990, and 2000 have been used to calculate the genetic demographic parameters of the Lugansk city population. The population is mostly Ukrainian and Russian. In the years studied, Ukrainians accounted for 49.4, 44.0, 44.6, and 48.7% of the population and Russians, for 46.3, 52.1, 50.7, and 45.6%, respectively. The total proportion of the two ethnic groups decreased from 97.3 to 94.6% for 40 years. The marriage contingency coefficient (K) with respect to ethnicity decreased from 0.16 to 0.07 in the period between 1960 and 1985 and increased from 0.10 to 0.24 between 1990 and 2000. The frequency of interethnic marriages (48.4, 50.9, 52.0, and 60.0%, respectively, in the years studied) indicate that the outbreeding component has been constantly increasing in the Lugansk population. The marriage assortativeness indices (A′) for Ukrainians were 0.2, 4.8, 2.1, and 6.0% in 1960, 1985, 1990, and 2000, respectively. For pooled minor ethnic groups, A′ values in these years were 25.6, 12.4, 18.9, and 6.6%, respectively. The marriage contingency coefficient (K) with respect to occupation increased in the period between 1960 and 1990 (0.14, 0.16, and 0.19 in 1960, 1985, and 1990, respectively), and K with respect to education decreased (0.35, 0.30, and 0.26, respectively).     

Genetic Demography of the Population of St. Petersburg: Migration Processes

Russian Journal of Genetics - The principal genetic demographic parameters that describe migration processes affecting the structure of the St. Petersburg population gene pool were determined on...     

Demography and Genetic Structure of a Recovering Grizzly Bear Population

ABSTRACT Grizzly bears (brown bears; Ursus arctos) are imperiled in the southern extent of their range worldwide. The threatened population in northwestern Montana, USA, has been managed for recovery since 1975; yet, no rigorous data were available to monitor program success. We used data from a large noninvasive genetic sampling effort conducted in 2004 and 33 years of physical captures to assess abundance, distribution, and genetic health of this population. We combined data from our 3 sampling methods (hair trap, bear rub, and physical capture) to construct individual bear encounter histories for use in Huggins—Pledger closed mark—recapture models. Our population estimate, Ň = 765 (95% CI = 715–831) was more than double the existing estimate derived from sightings of females with young. Based on our results, the estimated known, human-caused mortality rate in 2004 was 4.6% (95% CI = 4.2–4.9%), slightly above the 4% considered sustainable; however, the high proportion of female mortalities raises concern. We used location data from telemetry, confirmed sightings, and genetic sampling to estimate occupied habitat. We found that grizzly bears occupied 33,480 km² in the Northern Continental Divide Ecosystem (NCDE) during 1994–2007, including 10,340 km² beyond the Recovery Zone. We used factorial correspondence analysis to identify potential barriers to gene flow within this population. Our results suggested that genetic interchange recently increased in areas with low gene flow in the past; however, we also detected evidence of incipient fragmentation across the major transportation corridor in this ecosystem. Our results suggest that the NCDE population is faring better than previously thought, and they highlight the need for a more rigorous monitoring program.     

Demography and the Age of Rare Variants

Large whole-genome sequencing projects have provided access to much rare variation in human populations, which is highly informative about population structure and recent demography. Here, we show how the age of rare variants can be estimated from patterns of haplotype sharing and how these ages can be related to historical relationships between populations. We investigate the distribution of the age of variants occurring exactly twice ( variants) in a worldwide sample sequenced by the 1000 Genomes Project, revealing enormous variation across populations. The median age of haplotypes carrying variants is 50 to 160 generations across populations within Europe or Asia, and 170 to 320 generations within Africa. Haplotypes shared between continents are much older with median ages for haplotypes shared between Europe and Asia ranging from 320 to 670 generations. The distribution of the ages of haplotypes is informative about their demography, revealing recent bottlenecks, ancient splits, and more modern connections between populations. We see the effect of selection in the observation that functional variants are significantly younger than nonfunctional variants of the same frequency. This approach is relatively insensitive to mutation rate and complements other nonparametric methods for demographic inference.     

The Impact of Population Demography and Selection on the Genetic Architecture of Complex Traits

Population genetic studies have found evidence for dramatic population growth in recent human history. It is unclear how this recent population growth, combined with the effects of negative natural selection, has affected patterns of deleterious variation, as well as the number, frequency, and effect sizes of mutations that contribute risk to complex traits. Because researchers are performing exome sequencing studies aimed at uncovering the role of low-frequency variants in the risk of complex traits, this topic is of critical importance. Here I use simulations under population genetic models where a proportion of the heritability of the trait is accounted for by mutations in a subset of the exome. I show that recent population growth increases the proportion of nonsynonymous variants segregating in the population, but does not affect the genetic load relative to a population that did not expand. Under a model where a mutation''s effect on a trait is correlated with its effect on fitness, rare variants explain a greater portion of the additive genetic variance of the trait in a population that has recently expanded than in a population that did not recently expand. Further, when using a single-marker test, for a given false-positive rate and sample size, recent population growth decreases the expected number of significant associations with the trait relative to the number detected in a population that did not expand. However, in a model where there is no correlation between a mutation''s effect on fitness and the effect on the trait, common variants account for much of the additive genetic variance, regardless of demography. Moreover, here demography does not affect the number of significant associations detected. These findings suggest recent population history may be an important factor influencing the power of association tests and in accounting for the missing heritability of certain complex traits.     

Changing Patterns of Distribution of the Products of Photosynthesis in the Tomato Plant with Respect to Time and to the Age of a Leaf

Two series of experiments were conducted with tomato plantsgrown in a glasshouse. In the first series the second leaf ofa young plant was exposed to ¹⁴CO₂ for periods up to a maximumof 4 h and the distribution of the ¹⁴C-products was determinedeither at intervals of 10 and 30 min, 1, 2, 3, 4, 5, 6, 12,and 24 h, or 1, 2, 3, 5, 7, 11, and 15 days after the ¹⁴CO₂was initially supplied. Seventeen per cent of the containedradioactive carbon was exported during the first day and a further23 per cent during the following week. At the death of the leaf44 per cent of the carbon originally fixed was present in thedead structure. There is evidence that the roots re-export alarge proportion of the carbon products originally imported. In the second series the tenth leaf of a plant was suppliedwith ¹⁴CO₂, and 24 h later the relative amounts of radioactivitywere determined for every leaf, internode, and fruit truss andfor the roots and shoot apex. The plants were selected so thatleaf 10 was always immediately below truss 1. The experimentwas performed seven times, each time at a different stage bothin the life-cycle of the leaf and the development of the plant.There were differences in the total amounts of radioactivityfound at the end of each experiment but these differences werenot random. The pattern of distribution of the ¹⁴C exportedby leaf 10 changed as the plant developed. The percentage ofthe ¹⁴C initially fixed which was exported by leaf 10 rose toa peak early in its life and then fell sharply but the distributionof ¹⁴C exported followed a different pattern. For a long periodthere was a heavy accumulation of ¹⁴C in the internode immediatelybelow leaf 10 but later in development this was less evidentand the proportions reaching the roots increased. The internodeabove leaf 10 never showed the same degree of accumulation.Truss I dominated the distribution patterns during the phaseof its active growth. These results are discussed and a hypothesisto account for the changing patterns of distribution is presented.     

Differentiation of reduced products in embryozems of the Kuznetsk Basin

Accumulation of reduced products in the soil of initial, organics-accumulating, soddy, and humus-accumulating stages of soil formation in technogenic landscapes of the Kuznetsk Basin have been examined. The contribution of secondary reduced pedogenic products to the transformation of the initial lithogenous oxidation-reduction systems has been estimated.     

Genetic Demography of Ukrainian Urban Populations in the 1990s: Ethnic Geographic Characteristics of Migration in the Donetsk Population

Analysis of data on the birthplaces and ethnicity of persons who contracted marriages in the city of Donetsk in 1960, 1985, and 1992 demonstrated that the proportions of Russians and Ukrainians (the dominant ethnic groups among Donetsk residents) in the migration flow increased. The trend towards formation of ethnically disperse groups from the city residents became stronger. The index of isolation by distance (parameter b of Malecot's model) was 0.00103, 0.00071, and 0.00083 in 1960, 1985, and 1992, respectively. The proportions of long-range and short-range migrants increased by 1.2 times and decreased by 2.3 times, respectively, during the period studied. The locality size of the Donetsk population was 50, 62, and 53 km in 1960, 1985, and 1992, respectively. The highest isolation by distance was observed in Jews and Greeks and the lowest one, in Russians.     

Genetic Demography of Ukrainian Urban Populations in the 1990s: The Ethnic Composition of the Migration Flow in the Kharkov Population

Marriage records were used to study the dynamics of the migration flow into the population of Kharkov in 1960–1993. The decrease in the migration rate was accompanied by changes in the ethnic composition of the migrants. The entire migration flow from the republics of the Baltic region consisted of Russians and Ukrainians. The increase in the migration flow from Transcaucasia was mainly accounted for by the migration activity of indigenous populations. Most migrants from Moldova, Central Asia, Kazakhstan, and Kyrgyzstan were also representatives of the respective indigenous populations. Malecot's coefficient of isolation by distance (b) decreased from 0.00123 to 0.0081.     

Genetic Demographic Description of the Ust-Aldan Rural Population of Sakha Republic (Yakutia): Migrations and Marriage Structure

Migrations, dynamics of the gametic structure of rural populations, and marriage structure with respect to birthplaces and inbreeding estimated from isonymy have been studied in the Ust-Aldan ulus (administrative district) of Sakha Republic (Yakutia). The villages studied (Byadi, Dyupsya, and Cheriktey) are characterized by intense migration; however, the migration radius is small (most migrations occur within the district). The rural populations studied differ in the intensities and directions of gamete flows and their dynamics. There is no substantial gamete flow into the Ust-Aldan population from outside Sakha Republic. About 50% of marriages contracted in this population are homolocal (between residents of the same district); the endogamy is low (15%). In most cases of heterolocal marriages (contracted between residents of different districts), one of the spouses is a local resident. The inbreeding estimated from isonymy is F _IT = 0.002930 in Yakuts; it is mainly accounted for by the nonrandom component (F _IS = 0.002232 and F _ST = 0.000700).     

Group composition of iron and humus in the soils of anthropogenic landscapes in the Kuznetsk Basin

Behavior of iron forms and its differentiation in the soil profile in embryozems of different soil-climatic zones of the Kuznetsk Basin are considered for the first time as a diagnostic indicator of the character, intensity, and direction of soil processes.     

Comparison of Three Inbred Mouse Strains with Respect to General and Genetic Radiosensitivity

The radiosensitivities of three mouse strains (BALB/cLacY, C3H/SnY, and 101/HY) have been compared using the following parameters: survival after irradiation at a dose of 6–7 Gy, chromosome aberration frequency in bone marrow cells after irradiation at a dose of 1.5 Gy, and the change in testis weight and frequency of abnormal sperm heads (ASHs) after irradiation at doses from 0.5 to 4 Gy. Strain BALB/c is the most radiosensitive with respect to the survival and chromosome aberration frequency in the bone marrow but the most resistant with respect to the change in testis weight and the frequency of abnormal sperm heads. Strain 101/HY was the most resistant with respect to survival and chromosome aberration frequency in bone marrow after irradiation but the most radiosensitive with respect to testis damage.     

Population Growth and Demography of Common Loons in the Northern United States

ABSTRACT We used recent developments in theoretical population ecology to construct basic models of common loon (Gavia immer) demography and population dynamics. We parameterized these models using existing survival estimates and data from long-term monitoring of loon productivity and abundance. Our models include deterministic, 2-stage, density-independent matrix models, yielding population growth-rate estimates (λ) of 0.99 and 1.01 for intensively studied populations in our Wisconsin, USA, and New Hampshire, USA, study areas, respectively. Perturbation analysis of these models indicated that estimated growth rate is extremely sensitive to adult survival, as expected for this long-lived species. Also, we examined 20 years of count data for the 2 areas and evaluated support for a set of count-based models of population growth. We detected no temporal trend in Wisconsin, which would be consistent with fluctuation around an average equilibrium state but could also result from data limitations. For New Hampshire, the model set included varying formulations of density dependence and partitioning of stochasticity that were enabled by the annual sampling resolution. The best model for New Hampshire included density regulation of population growth and, along with the demographic analyses for both areas, provided insight into the possible importance of breeding habitat availability and the abundance of nonbreeding adults. Based on these results, we recommend that conservation organizations include nonbreeder abundance in common loon monitoring efforts and that additional emphasis be placed on identifying and managing human influences on adult loon survival.