scholarly journals Indexes of natural selection in Kharkiv population

2018 ◽  
Vol 22 ◽  
pp. 56-61 ◽  
Author(s):  
N. O. Kozak ◽  
L. A. Atramentova
Keyword(s):  
Natural Selection ◽  
Selection Index ◽  
Differential Mortality ◽  
Human Populations ◽  
Differential Fertility ◽  
Global Trends ◽  
Mortality Index ◽  
Significant Difference ◽  
Ectopic Pregnancies ◽  
Total Selection

Aim. Reproductive behavior of women has particular importance in the reproduction of the population and depends on cultural characteristics and religious views. Number of birth and medical abortions become artificially regulated; nevertheless selection in human populations does not disappear. Therefore, the aim of this task to study the direction and intensity of indexes of natural selection and the dynamics of the gene pool in the Kharkiv population for two adjacent generations. Methods. The material was collected in 2017. Anonymous questionnaires were conducted for women in postreproductive age. The questionnaire includes questions which reflect a woman's gynecological and obstetrical anamnesis. The number of pregnancies and their outcomes was calculated: medical and spontaneous abortions, ectopic pregnancies, number of stillbirths and live births. Results. In one generation, the total selection index decrease from 0.29 to 0.28, while the differential fertility index is much higher than the differential mortality index. The average number of pregnancies and medical abortions reduced in the younger generation with statistically significant difference. Conclusions. The Kharkov population is characterized by a narrow type of reproduction. The dynamics of Crow's indexes are in line with global trends. From the older generation to the younger the total selection index decreases gradually.Keywords: reproductive characteristics,Kharkov population, Crow's index, selection, generations.

scholarly journals Dynamics of natural selection in two generations (on the example of the population of the Kirovograd region)

2021 ◽  
Vol 29 ◽  
pp. 152-156
Author(s):  
K. K. Kovleva ◽  
N.A. Kozak
Keyword(s):  
Natural Selection ◽  
First Generation ◽  
Second Generation ◽  
Selection Index ◽  
Genetic Load ◽  
Modern Medicine ◽  
Reproductive Age ◽  
Human Populations ◽  
Medical Histories ◽  
Total Selection

Aim. In connection with the success of modern medicine, the pressure of natural selection in various civilized human populations is weakening, which leads to the accumulation of a genetic load. The purpose of this work was to trace the change in the intensity of natural selection among population of the Kirovograd region in two successive generations. Methods. The collection of material was carried out in 2020 and 2021. Anonymous questionnaires were conducted and medical histories of women of post-reproductive age of the Kirovograd region were studied. The first generation included 40 women born in 1937–1959; the second generation consists of 273 women born in 1960–1981. Results. The total selection index was 0.27 in the first generation, and 0.37 in the second generation. The percentage of women who have not had pregnancies increased from the first generation to the second from 2.5 to 3.7, respectively. Conclusions. The index of total selection in the Kirovograd region population for one generation increased by almost one and a half times (from 0.27 to 0.37), as well as the index of differential fertility (from 0.25 to 0.35). Keywords: reproductive characteristics, Kirovograd population, Crow's index, selection, generations.

scholarly journals Dynamics of indexes of reproduction and selection in three generations of the urbanized population

2020 ◽  
Vol 26 ◽  
pp. 61-66
Author(s):  
N. O. Kozak ◽  
L. A. Atramentova
Keyword(s):  
First Generation ◽  
Selection Index ◽  
Reproductive Technologies ◽  
Differential Mortality ◽  
Third Generation ◽  
Differential Fertility ◽  
Quantitative Characteristics ◽  
History Of ◽  
Successive Generations ◽  
Total Selection

Aim. Due to the fact that women's reproductive behavior has been changing with the development of civilization, from natural uncontrolled fertility in the early stages of human development to reproductive technologies in our time, the aim of this work was to study the direction and intensity of natural selection index and changes of the quantitative characteristics of reproduction in women residents of Kharkiv in three successive generations. Methods. Material was collected in 1990 and 2017. The obstetric and gynecological history of the inhabitants of Kharkiv was studied. The first generation included 589 women who were born in 1900–1925, 244 women born in the period 1928–1955, made up the second generation, 288 women who were born in 1956–1979, were assigned to third generation. Results. The total selection index is reduced from 0.56 in the first generation to 0.29 and 0.28 in the second and third generations, respectively. Over the eighty-year period, the differential fertility rate has decreased. The percentage of women with pathological pregnancies increased from 4.9 in the first generation, to 22.5 in the second and 18.4 in the third generation. Conclusions. The total selection index in the Kharkiv population into three successive generations has decreased by half: from 0.56 to 0.28, the index of differential mortality has decreased by almost four times. Keywords: reproductive characteristics, Kharkov population, Crow's index, selection, generations.

scholarly journals Indexes of Natural Selection, Migration and Reproductive Characteristics in Lutsk Population, West Ukraine

2021 ◽  
Vol 1 (3) ◽  
pp. 59-64
Author(s):  
N. Kozak ◽  
L. Atramentova
Keyword(s):  
Natural Selection ◽  
First Generation ◽  
Prenatal Development ◽  
Reproductive Age ◽  
Human Populations ◽  
Reproductive Characteristics ◽  
Two Generations ◽  
Selection Indexes ◽  
Ectopic Pregnancies ◽  
Genetic Burden

In human populations natural selection is shifting to the side of prenatal development and appears as negative outcomes of pregnancies such as spontaneous abortions, ectopic pregnancies and stillbirths. Therefore, it is important to study dynamics of changes in reproductive characteristics and selection indexes of the populations in order to predict possible problems and numbers of genetic burden in the populations. Ukraine is poorly studied in this area. The aim of the study was to investigate indicators which characterize the population structure of Lutsk city, the intensity of natural selection, migration and their dynamics in two generations. 583 post-reproductive age females were anonymously questioned. Age, places of birth of the couple, the number of pregnancies and their outcomes were considered. Results show that natural selection indexes (Crow’s indexes) are decreasing from the first generation (0,26) to the second (0,20). Migration coefficients in the population of Lutsk decreased from 0.89 to 0.82 per generation and show intensive urbanization of the city for the studied time. The efficiency of the migration is low, since the biggest number of migrants come from the villages of the Volyn region (45% for first generations and 64% for the second one), or adjacent regions of Ukraine (35% and 27%, respectively). The population of Lutsk has a narrowed type of reproduction, where average number of offspring per female equal 1,86 for the first generation and 1,73 for the second generation.

scholarly journals Selection intensity and its opportunity among the Santal women of Keonjhar, Odisha, India

2015 ◽  
Vol 1 (4) ◽  
pp. 203
Author(s):  
Subal Das ◽  
Binoy Kumar Kuiti ◽  
Kaushik Bose
Keyword(s):  
Natural Selection ◽  
Selection Intensity ◽  
Intensity Index ◽  
It Value ◽  
Fertility Index ◽  
Total Index ◽  
Mortality Index ◽  
Postnatal Mortality ◽  
Total Selection

Present study dealt with the opportunity of natural selection using Crows index and Johnston and Kensinger's Index among the Santal womens of Keonjhar, Odisha, India. Mortality index (Im), Fertility index (If) and total selection intensity index (I) were analyzed among the studied population. The Crows total index (It) value was found to be 0.7246. The mortality (Im) component was found to be 0.5385 while the fertility (If) component was found to be 0.1846. The contribution of fertility component is greater than that of mortality component among the present studied population using Crows index. According to Johnston and Kesinger the total index (It) was found to be 0.8367. Where, fertility component was found to be 0.0885, Prenatal mortality component (Ime) and Postnatal mortality component (Ime/Pb) where observed to be 0.1356 and 0.1540. Therefore, it has been clear from the result that prenatal mortality contributes higher than that of postnatal mortality for selection. i.e., Johnston and Kesingers Index (0.8367) contributes higher for the opportunity of natural selection than Crows Index (0.7246).

Genetic load and biological changes to extant humans

2020 ◽  
pp. 1-4
Author(s):  
Arthur Saniotis ◽  
Maciej Henneberg ◽  
Kazhaleh Mohammadi
Keyword(s):  
Natural Selection ◽  
Current Knowledge ◽  
Genetic Load ◽  
Differential Fertility ◽  
Medical Interventions ◽  
Deleterious Alleles ◽  
Gradual Process ◽  
Genetic Complexity ◽  
Sexual Recombination ◽  
Improved Sanitation

Abstract Extant humans are currently increasing their genetic load, which is informing present and future human microevolution. This has been a gradual process that has been rising over the last centuries as a consequence of improved sanitation, nutritional improvements, advancements in microbiology and medical interventions, which have relaxed natural selection. Moreover, a reduction in infant and child mortality and changing societal attitudes towards fertility have led to a decrease in total fertility rates (TFRs) since the 19th century. Generally speaking, decreases in differential fertility and mortality have meant that there is less opportunity for natural selection to eliminate deleterious mutations from the human gene pool. It has been argued that the average human may carry ~250–300 mutations that are mostly deleterious, as well as several hundred less-deleterious variants. These deleterious alleles in extant humans mean that our fitness is being constrained. While such alleles are viewed as reducing human fitness, they may also have had an adaptive function in the past, such as assisting in genetic complexity, sexual recombination and diploidy. Saying this, our current knowledge on these fitness compromising alleles is still lacking.

scholarly journals The emergence of latent infection in the early evolution of Mycobacterium tuberculosis

2016 ◽  
Vol 283 (1831) ◽  
pp. 20160499 ◽  
Author(s):  
Rebecca H. Chisholm ◽  
Mark M. Tanaka
Keyword(s):  
Mathematical Model ◽  
Immune Response ◽  
Mycobacterium Tuberculosis ◽  
Genetic Variation ◽  
Natural Selection ◽  
Natural History ◽  
Latent Infection ◽  
Human Populations ◽  
Safe Harbour ◽  
Active Disease

Mycobacterium tuberculosis has an unusual natural history in that the vast majority of its human hosts enter a latent state that is both non-infectious and devoid of any symptoms of disease. From the pathogen perspective, it seems counterproductive to relinquish reproductive opportunities to achieve a détente with the host immune response. However, a small fraction of latent infections reactivate to the disease state. Thus, latency has been argued to provide a safe harbour for future infections which optimizes the persistence of M. tuberculosis in human populations. Yet, if a pathogen begins interactions with humans as an active disease without latency, how could it begin to evolve latency properties without incurring an immediate reproductive disadvantage? We address this question with a mathematical model. Results suggest that the emergence of tuberculosis latency may have been enabled by a mechanism akin to cryptic genetic variation in that detrimental latency properties were hidden from natural selection until their expression became evolutionarily favoured.

scholarly journals Genetic diversity and natural selection footprints of the glycine amidinotransferase gene in various human populations

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Asifullah Khan ◽  
Lei Tian ◽  
Chao Zhang ◽  
Kai Yuan ◽  
Shuhua Xu
Keyword(s):  
Genetic Diversity ◽  
Natural Selection ◽  
Human Populations

GEOSPATIAL ASSESSMENT BASED ON FERTILITY AND MORTALITY DIFFERENTIAL INDICES OF NATURAL SELECTION IN NORTH-WEST AND EASTERN HIMALAYAN POPULATIONS

2016 ◽  
Vol 49 (6) ◽  
pp. 811-825
Author(s):  
Krishan Sharma
Keyword(s):  
High Altitude ◽  
Secondary Data ◽  
Himachal Pradesh ◽  
Embryonic Mortality ◽  
Human Populations ◽  
Similar Data ◽  
Lower Altitude ◽  
North West ◽  
Selection Intensities ◽  
Total Selection

SummaryThere is contradictory evidence of having fewer live births and higher embryonic mortality among high-altitude populations than their counterparts at lower altitude. This study explores the geospatial differences in selection intensities among human populations living in different ecological settings. Reproductive data from post-menopausal women were collected from 75 women from near Shimla, Himachal Pradesh, at an altitude of 2150 m above sea level and 100 women from Jind, Haryana, at an altitude of 227 m. Secondary data were taken from 85 women from the Kinnaur district of Himachal Pradesh at an average altitude of 3420 m. A comparison of the study data was made with similar data from different populations living in the western and eastern Himalayas. The total selection intensity index based on Johnston and Kensinger’s index was highest in Shimla and lowest in Kinnaur. The fertility selection component was highest in Shimla and lowest in Kinnaur. The prenatal mortality contribution to the total selection was highest in Shimla (30.76%) and lowest in Kinnaur (2.14%), while the contributions of normalized postnatal mortality were 16.39% and 57.80% in Shimla and Kinnaur, respectively. The fertility component of selection was higher than the mortality component in Shimla, while in the other two places the reverse was observed. Hypoxic conditions at high altitude seem to have little effect on the fertility and embryonic mortality rates of indigenous people. The geospatial differences in the selection intensities may be due to differences in ethnic, behavioural ecology, environmental, cultural and socioeconomic factors.

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