scholarly journals Formation of adaptive types as a process of microevolution

2021 ◽  
pp. 72-82
Author(s):  
Andrew I. Kozlov ◽  
◽  
Keyword(s):  
Ethnic Groups ◽  
Population Genetic ◽  
Modern Human ◽  
Allele Frequencies ◽  
Human Populations ◽  
Vdr Gene ◽  
Ecological Adaptations ◽  
Environmental Adaptations ◽  
Genetic Specificity ◽  
Genotype And Allele Frequencies

The study populations have been grouped into two clusters. The first constituted the ethnic groups that are anthropologically affine but differ in adaptive types and husbandry practices. The second included the anthropologically unrelated ethnic groups having similar environment economy systems and adaptive types. We analyzed the genotype and allele frequencies of the metabolism-associated APOE, LCT, TREH, UCP1 genes, and Fok1 and BsmI polymorphisms of VDR gene. A total of 749 samples in the study represents the ethnic groups of Komi-Permyaks (n=181), Komi (n=235), Komi-Izhems (n=200), Shores (n=133). Results. A resemblance in the morphological and physiological complexes that have convergently developed in the course of environmental adaptations have been shown to reflect similarities in the gene features of anthropologically unrelated populations. In contrast, in the historically related groups that have utilized different biotopes and types of husbandry, there are growing divergence in the frequencies of metabolism-associated genotypes and alleles. These findings imply that ecological adaptations of modern human populations drive the minor changes in allele frequencies, which have occurred over a few generations. Conclusion. The apparent morpho-physiological and population-genetic specificity of the adaptive types allows us to regard the process of their formation as microevolution.

scholarly journals The timing of human adaptation from Neanderthal introgression

2020 ◽  
Author(s):  
Sivan Yair ◽  
Kristin M. Lee ◽  
Graham Coop
Keyword(s):  
Demographic History ◽  
Low Frequency ◽  
Modern Human ◽  
Allele Frequencies ◽  
Population Divergence ◽  
Human Populations ◽  
Human Adaptation ◽  
Adaptive Introgression ◽  
History Of ◽  
Spatio Temporal

AbstractAdmixture has the potential to facilitate adaptation by providing alleles that are immediately adaptive in a new environment or by simply increasing the long term reservoir of genetic diversity for future adaptation. A growing number of cases of adaptive introgression are being identified in species across the tree of life, however the timing of selection, and therefore the importance of the different evolutionary roles of admixture, is typically unknown. Here, we investigate the spatio-temporal history of selection favoring Neanderthal-introgressed alleles in modern human populations. Using both ancient and present-day samples of modern humans, we integrate the known demographic history of populations, namely population divergence and migration, with tests for selection. We model how a sweep placed along different branches of an admixture graph acts to modify the variance and covariance in neutral allele frequencies among populations at linked loci. Using a method based on this model of allele frequencies, we study previously identified cases of Neanderthal adaptive introgression. From these, we identify cases in which Neanderthal introgressed alleles were quickly beneficial and other cases in which they persisted at low frequency for some time. For some of the alleles that persisted at low frequency, we show that selection likely independently favored them later on in geographically separated populations. Our work highlights how admixture with ancient hominins has contributed to modern human adaptation, contextualizes observed levels of Neanderthal ancestry in present-day and ancient samples, and identifies cases of temporally varying selection that are sometimes shared across large geographic distances.

scholarly journals The timing of human adaptation from Neanderthal introgression

Genetics ◽  
2021 ◽  
Author(s):  
Sivan Yair ◽  
Kristin M Lee ◽  
Graham Coop
Keyword(s):  
Demographic History ◽  
Low Frequency ◽  
Modern Human ◽  
Allele Frequencies ◽  
Population Divergence ◽  
Human Populations ◽  
Human Adaptation ◽  
Adaptive Introgression ◽  
History Of ◽  
Spatio Temporal

Abstract Admixture has the potential to facilitate adaptation by providing alleles that are immediately adaptive in a new environment or by simply increasing the long term reservoir of genetic diversity for future adaptation. A growing number of cases of adaptive introgression are being identified in species across the tree of life, however the timing of selection, and therefore the importance of the different evolutionary roles of admixture, is typically unknown. Here, we investigate the spatio-temporal history of selection favoring Neanderthal-introgressed alleles in modern human populations. Using both ancient and present-day samples of modern humans, we integrate the known demographic history of populations, namely population divergence and migration, with tests for selection. We model how a sweep placed along different branches of an admixture graph acts to modify the variance and covariance in neutral allele frequencies among populations at linked loci. Using a method based on this model of allele frequencies, we study previously identified cases of Neanderthal adaptive introgression. From these, we identify cases in which Neanderthal introgressed alleles were quickly beneficial and other cases in which they persisted at low frequency for some time. For some of the alleles that persisted at low frequency, we show that selection likely independently favored them later on in geographically separated populations. Our work highlights how admixture with ancient hominins has contributed to modern human adaptation and contextualizes observed levels of Neanderthal ancestry in present-day and ancient samples.

Systematic benchmark of ancient DNA read mapping

2021 ◽  
Author(s):  
Adrien Oliva ◽  
Raymond Tobler ◽  
Alan Cooper ◽  
Bastien Llamas ◽  
Yassine Souilmi
Keyword(s):  
Ancient Dna ◽  
Dna Sequences ◽  
Population Genetic ◽  
Reference Genome ◽  
Population Data ◽  
Human Populations ◽  
Current Standard ◽  
Read Mapping ◽  
Reference Bias ◽  
The Impact

Abstract The current standard practice for assembling individual genomes involves mapping millions of short DNA sequences (also known as DNA ‘reads’) against a pre-constructed reference genome. Mapping vast amounts of short reads in a timely manner is a computationally challenging task that inevitably produces artefacts, including biases against alleles not found in the reference genome. This reference bias and other mapping artefacts are expected to be exacerbated in ancient DNA (aDNA) studies, which rely on the analysis of low quantities of damaged and very short DNA fragments (~30–80 bp). Nevertheless, the current gold-standard mapping strategies for aDNA studies have effectively remained unchanged for nearly a decade, during which time new software has emerged. In this study, we used simulated aDNA reads from three different human populations to benchmark the performance of 30 distinct mapping strategies implemented across four different read mapping software—BWA-aln, BWA-mem, NovoAlign and Bowtie2—and quantified the impact of reference bias in downstream population genetic analyses. We show that specific NovoAlign, BWA-aln and BWA-mem parameterizations achieve high mapping precision with low levels of reference bias, particularly after filtering out reads with low mapping qualities. However, unbiased NovoAlign results required the use of an IUPAC reference genome. While relevant only to aDNA projects where reference population data are available, the benefit of using an IUPAC reference demonstrates the value of incorporating population genetic information into the aDNA mapping process, echoing recent results based on graph genome representations.

scholarly journals Functional relationship between dental macrowear and diet in Late Pleistocene and recent modern human populations

2018 ◽  
Vol 28 (2) ◽  
pp. 153-161 ◽  
Author(s):  
Luca Fiorenza ◽  
Stefano Benazzi ◽  
Gregorio Oxilia ◽  
Ottmar Kullmer
Keyword(s):  
Late Pleistocene ◽  
Functional Relationship ◽  
Modern Human ◽  
Human Populations

scholarly journals The Genome of a Mongolian Individual Reveals the Genetic Imprints of Mongolians on Modern Human Populations

2014 ◽  
Vol 6 (12) ◽  
pp. 3122-3136 ◽  
Author(s):  
Haihua Bai ◽  
Xiaosen Guo ◽  
Dong Zhang ◽  
Narisu Narisu ◽  
Junjie Bu ◽  
...  
Keyword(s):  
Modern Human ◽  
Human Populations

scholarly journals Association between osteoporosis and polymorphisms of the bone estrogen receptor 1, calcitonin receptor genes in Mongolian postmenopausal women

2014 ◽  
Author(s):  
Unentsatsral Lkhagvasuren ◽  
Sarantuya Jav ◽  
Ochbadrakh Batjargal ◽  
Myagmarsuren Batsukh
Keyword(s):  
Estrogen Receptor ◽  
Postmenopausal Women ◽  
Genomic Dna ◽  
Venous Blood ◽  
Allele Frequencies ◽  
Calcitonin Receptor ◽  
Significant Difference ◽  
Pcr Rflp ◽  
Estrogen Receptor 1 ◽  
Genotype And Allele Frequencies

In this study, we have investigated the association between osteoporosis and estrogen receptor 1 (ER1) 397 T>C, and calcitonin receptor (CALCR) 1340 T>C polymorphisms. Genomic DNA was obtained from 104 persons (52 osteoporotic and 52 healthy controls). Genomic DNA was extracted from EDTA-preserved peripheral venous blood of patients and controls and analyzed by PCR-RFLP. As a result, there was no statistically significant difference in the genotype and allele frequencies of patients and controls for ER1 397 T>C and CALCR 1340 T>C polymorphisms. ER1 CC and TC single nucleotides genotypes compared with TT genotypes was found more significantly women with osteoporosis [p=0.016; p=0.0046, OR=2.66; 0.44, 95% CI 1.185-5.988; 0.199-0.991)]. There was no statistically significant difference in the genotype and allele frequencies of patient and controls for ER1 combined nucleotides [p=0,148, OR=1.051, 95% CI (0.993–1.112)]. Our study showed that CALCR genes single and combined nucleotides genotypes were not significant women with osteoporotic and healthy postmenopausal women.

scholarly journals Stroke Disparities: From Observations to Actions

Stroke ◽  
2020 ◽  
Vol 51 (11) ◽  
pp. 3392-3405 ◽  
Author(s):  
Ralph L. Sacco
Keyword(s):  
Risk Factor ◽  
Ethnic Groups ◽  
Cardiovascular Health ◽  
Disease Incidence ◽  
Human Populations ◽  
Stroke Incidence ◽  
Ideal Cardiovascular Health ◽  
Awareness Campaigns ◽  
Study Results ◽  
Improvement Programs

Numerous epidemiological studies have demonstrated stroke disparities across race and ethnic groups. The goal of the NOMAS (Northern Manhattan Study) was to evaluate race and ethnic differences in stroke within a community with 3 different race-ethnic groups. Starting as a population-based incidence and case-control study, the study evolved into a cohort study. Results from NOMAS have demonstrated differences in stroke incidence, subtypes, risk factors, and outcomes. Disparities in ideal cardiovascular health can help explain many differences in stroke incidence and call for tailored risk factor modification through innovative portals to shift more diverse subjects to ideal cardiovascular health. The results of NOMAS and multiple other studies have provided foundational data to support interventions. Conceptual models to address health disparities have called for moving from detecting disparities in disease incidence, to determining the underlying causes of disparities and developing interventions, and then to testing interventions in human populations. Further actions to address race and ethnic stroke disparities are needed including innovative risk factor interventions, stroke awareness campaigns, quality improvement programs, workforce diversification, and accelerating policy changes.

Palaeolithic Assemblages associated with Youngest Toba Tuff deposits from the Upper Gundlakamma river basin, Andhra Pradesh, India

2021 ◽  
pp. SP515-2020-187
Author(s):  
Devara Anil ◽  
P. Ajithprasad ◽  
Mahesh Vrushab
Keyword(s):  
River Basin ◽  
Andhra Pradesh ◽  
Modern Human ◽  
Human Populations ◽  
Content Type ◽  
Before And After ◽  
Climatic Impacts ◽  
Supplementary Material ◽  
Human Colonization ◽  
Behavioural Adaptations

AbstractArchaeological and geological remains associated with the Youngest Toba Tuff (YTT) deposits in India are seen as significant proxies for reconstructing 1) Initial modern human colonization of India and 2) Possible climatic impacts of the Toba super-eruption of 74 ka on Indian climate and hominin behaviour. In order to gain further insights into the environmental impacts and behavioural adaptations of human populations in India before and after the Toba eruption, we investigated archaeological horizons associated with the Toba ash beds along the Gundlakamma basin in Prakasam District, Andhra Pradesh, India. Here, lithic artefacts were identified below and above the YTT deposits. The YTT deposits in the Gundlakamma river basin has a maximum thickness of 50 cm, comparatively thinner than those at the better investigated valleys of the adjacent Jurreru and Sagileru in Andhra Pradesh and the Son, Madhya Pradesh, India. Our surveys indicate that the Palaeolithic assemblages associated with YTT deposits from the Gundlakamma river basin can provide significant insights on the issues and debates surrounding the Toba archaeology.Supplementary material at https://doi.org/10.6084/m9.figshare.c.5729449

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