scholarly journals Quantifying the prevalence of assortative mating in a human population

2019 ◽  
Author(s):  
Klaus Jaffe
Keyword(s):  
Assortative Mating ◽  
Genetic Relatedness ◽  
Random Mating ◽  
Human Populations ◽  
Genetic Composition ◽  
Genetic Studies ◽  
Maintenance Of Sex ◽  
Animal Populations ◽  
The Uk ◽  
First Time

AbstractFor the first time, empirical evidence allowed to construct the frequency distribution of a genetic relatedness index between the parents of about half a million individuals living in the UK. The results suggest that over 30% of the population is the product of parents mating assortatively. The rest is probably the offspring of parents matching the genetic composition of their partners randomly. High degrees of genetic relatedness between parents, i.e. extreme inbreeding, was rare. This result shows that assortative mating is likely to be highly prevalent in human populations. Thus, assuming only random mating among humans, as widely done in ecology and population genetic studies, is not an appropriate approximation to reality. The existence of assortative mating has to be accounted for. The results suggest the conclusion that both, assortative and random mating, are evolutionary stable strategies. This improved insight allows to better understand complex evolutionary phenomena, such as the emergence and maintenance of sex, the speed of adaptation, runaway adaptation, maintenance of cooperation, and many others in human and animal populations.

scholarly journals Diet-based assortative mating through sexual imprinting

2018 ◽  
Author(s):  
E.K. Delaney ◽  
H.E. Hoekstra
Keyword(s):  
Assortative Mating ◽  
Random Mating ◽  
Sexual Isolation ◽  
In Utero ◽  
Sexual Imprinting ◽  
Peromyscus Gossypinus ◽  
Animal Populations ◽  
Cotton Mouse ◽  
Flavored Water ◽  
Dietary Cues

AbstractSpeciation is facilitated when traits subject to divergent selection also contribute to non-random mating—so-called ‘magic traits.’ Diet is a potential magic trait in animal populations because selection for divergence in consumed food may contribute to assortative mating and therefore sexual isolation. However, the mechanisms causing positive diet-based assortment are largely unknown. Here, using diet manipulations in a sexually imprinting species of mouse, Peromyscus gossypinus (the cotton mouse), we tested the hypothesis that sexual imprinting on a divergent diet could be a mechanism that generates rapid and significant sexual isolation. We provided breeding pairs with novel garlic- or orange-flavored water and assessed whether their offspring, exposed to these flavors in utero and in the nest before weaning, later preferred mates that consumed the same flavored water as their parents. While males showed no preference, females preferred males of their parental diet, which generated significant sexual isolation. Thus, our experiment demonstrates that sexual imprinting on dietary cues learned in utero and/or postnatally can facilitate reproductive isolation and potentially speciation.

scholarly journals The Effects of Migration and Assortative Mating on Admixture Linkage Disequilibrium

2016 ◽  
Author(s):  
Noah Zaitlen ◽  
Scott Huntsman ◽  
Donglei Hu ◽  
Melissa Spear ◽  
Celeste Eng ◽  
...  
Keyword(s):  
Linkage Disequilibrium ◽  
African Americans ◽  
Assortative Mating ◽  
Random Mating ◽  
Historical Narrative ◽  
Model Complexity ◽  
Human Populations ◽  
Local Ancestry ◽  
Admixed Population ◽  
Demographic Inference

1AbstractStatistical models in medical and population genetics typically assume that individuals assort randomly in a population. While this simplifies model complexity, it contradicts an increasing body of evidence of non-random mating in human populations. Specifically, it has been shown that assortative mating is significantly affected by genomic ancestry. In this work we examine the effects of ancestry-assortative mating on the linkage disequilibrium between local ancestry tracks of individuals in an admixed population. To accomplish this, we develop an extension to the Wright-Fisher model that allows for ancestry based assortative mating. We show that ancestry-assortment perturbs the distribution of local ancestry linkage disequilibrium (LAD) and the variance of ancestry in a population as a function of the number of generations since admixture. This assortment effect can induce errors in demographic inference of admixed populations when methods assume random mating. We derive closed form formulae for LAD under an assortative-mating model with and without migration. We observe that LAD depends on the correlation of global ancestry of couples in each generation, the migration rate of each of the ancestral populations, the initial proportions of ancestral populations, and the number of generations since admixture. We also present the first evidence of ancestry-assortment in African Americans and examine LAD in simulated and real admixed population data of African Americans. We find that demographic inference under the assumption of random mating significantly underestimates the number of generations since admixture, and that accounting for assortative mating using the patterns of LAD results in estimates that more closely agrees with the historical narrative.

scholarly journals Survey of the Bradysia odoriphaga Transcriptome Using PacBio Single-Molecule Long-Read Sequencing

Genes ◽  
2019 ◽  
Vol 10 (6) ◽  
pp. 481 ◽  
Author(s):  
Chen ◽  
Lin ◽  
Xie ◽  
Zhong ◽  
Zhang ◽  
...  
Keyword(s):  
Insecticide Resistance ◽  
Single Molecule ◽  
Functional Categories ◽  
Genetic Studies ◽  
Sequencing Technologies ◽  
Clusters Of Orthologous Groups ◽  
Long Read ◽  
Main Gene ◽  
First Time ◽  
Main Factor

The damage caused by Bradysia odoriphaga is the main factor threatening the production of vegetables in the Liliaceae family. However, few genetic studies of B. odoriphaga have been conducted because of a lack of genomic resources. Many long-read sequencing technologies have been developed in the last decade; therefore, in this study, the transcriptome including all development stages of B. odoriphaga was sequenced for the first time by Pacific single-molecule long-read sequencing. Here, 39,129 isoforms were generated, and 35,645 were found to have annotation results when checked against sequences available in different databases. Overall, 18,473 isoforms were distributed in 25 various Clusters of Orthologous Groups, and 11,880 isoforms were categorized into 60 functional groups that belonged to the three main Gene Ontology classifications. Moreover, 30,610 isoforms were assigned into 44 functional categories belonging to six main Kyoto Encyclopedia of Genes and Genomes functional categories. Coding DNA sequence (CDS) prediction showed that 36,419 out of 39,129 isoforms were predicted to have CDS, and 4319 simple sequence repeats were detected in total. Finally, 266 insecticide resistance and metabolism-related isoforms were identified as candidate genes for further investigation of insecticide resistance and metabolism in B. odoriphaga.

To bee or not to beet with neonicotinoids

2021 ◽  
Vol 23 (2) ◽  
pp. 103-109
Author(s):  
Lynda M. Warren
Keyword(s):  
Sugar Beet ◽  
Weather Conditions ◽  
The European Union ◽  
Environmental Standards ◽  
Economic Interests ◽  
Precautionary Approach ◽  
The United Kingdom ◽  
Commercial Sugar ◽  
The Uk ◽  
First Time

In January 2021 the UK government granted an application for authorisation to use thiamethoxam, a neonicotinoid pesticide, to protect commercial sugar beet crops from attack by viruses transmitted by aphids. This was the first time such an authorisation had been granted in the United Kingdom (UK) and there were concerns that it signalled a weakening of environmental standards now that the UK was no longer part of the European Union. In fact, similar authorisations had been granted by several European Member States in the last 2 years, despite the ban on the use of neonicotinoids introduced in 2018. Nevertheless, the reasons for granting the authorisation do suggest that the balance between adopting a precautionary approach to environmental protection and taking emergency action to protect economic interests may have shifted. It was acknowledged that the proposed mitigation to safeguard bees and other wildlife was not entirely satisfactory. In the end, due to unforeseen weather conditions it meant that the pesticide is not necessary, which in itself demonstrates that short-term emergency measures are unsuitable for dealing with the problem. If the sugar beet industry is to continue to prosper in the UK, it will need to be managed in a way that provides resistance to virus infection without the use of controversial chemicals.

History of Headache Research in Denmark

Cephalalgia ◽  
2001 ◽  
Vol 21 (7) ◽  
pp. 748-752 ◽  
Author(s):  
P Tfelt-Hansen
Keyword(s):  
Migraine With Aura ◽  
Tension Type Headache ◽  
Regional Cerebral Blood ◽  
Danish Population ◽  
Genetic Studies ◽  
History Of ◽  
Headache Clinic ◽  
Type Headache ◽  
Acute Headache ◽  
First Time

Headache research in Denmark started with the description in 1949 by Dalsgaard-Nielsen of the percutaneous nitroglycerin test. In 1976 Jes Olesen started The Copenhagen Acute Headache Clinic and from that time modern headache research began in Denmark. Specific changes in regional cerebral blood flow during attacks of migraine with aura, spreading oligaemia, were described for the first time in 1980. The first headache classification with operational diagnostic criteria was published in 1988 and used in a Danish population study from 1989. The lifetime prevalence of migraine was 8% in men and 25% in women. An intravenous nitroglycerin test was introduced in 1989 and has been developed as an experimental headache model. In 1993 it was suggested by Jes Olesen et al. that NO supersensitivity could be a possible molecular mechanism of migraine pain. Recent genetic studies have supported the distinction between migraine with aura and migraine without aura. From the middle of the 1980s the pathophysiology of tension-type headache has been investigated and recent results indicate central sensitization in patients with chronic tension-type headache.

The duties of impartiality, disclosure, and confidentiality: lessons from a London-seated arbitration

2021 ◽  
Author(s):  
Samuel Yee Ching Leung ◽  
Alex Chun Hei Chan
Keyword(s):  
United Kingdom ◽  
Important Case ◽  
Careful Examination ◽  
International Arbitration ◽  
The United Kingdom ◽  
Key Concepts ◽  
The Uk ◽  
First Time

Abstract Halliburton Company v Chubb Bermuda Insurance Ltd (formerly known as Ace Bermuda Insurance Ltd [2020] UKSC 48 is an important case not only to the UK but also to the international arbitration community for several reasons: first, it examines indispensable duties in international arbitration and for the first time recognises and explicates upon the duty of disclosure at the highest court of the United Kingdom; secondly, it addresses and clarifies key concepts in international arbitration; thirdly, it confirms the objective nature of the test of justifiable doubts which has wider implications for other arbitral forums; fourthly, it illustrates how the duties of impartiality, disclosure, and confidentiality interact with and affect each other and how the key concepts should be applied to this interaction; and finally, it lays down useful guidance for arbitrators. For these reasons, this case deserves close and careful examination. This article aims to explain the significance of the aforesaid and suggests that, in addition to what has been addressed, further judicial explanations are warranted in what other aspects.

Defence Medical Services’ REBOA training course

2021 ◽  
pp. bmjmilitary-2021-001926
Author(s):  
Max E R Marsden ◽  
C Park ◽  
J Barratt ◽  
N Tai ◽  
P Rees
Keyword(s):  
Training Programme ◽  
Balloon Occlusion ◽  
Medical Services ◽  
Skill Retention ◽  
Training Course ◽  
Challenges And Opportunities ◽  
Haemorrhage Control ◽  
Surgical Teams ◽  
The Uk ◽  
First Time

Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) enables temporary haemorrhage control and physiological stabilisation. This article describes the bespoke Defence Medical Services (DMS) training package for effectively using REBOA. The article covers how the course was designed, how the key learning objectives are taught, participant feedback and the authors’ perceptions of future training challenges and opportunities. Since the inaugural training course in April 2019, the authors have delivered six courses, training over 100 clinicians. For the first time in the UK DMS, we designed and delivered a robust specialist endovascular training programme, with demonstrable, significant increases in confidence and competence. As a result of this course, the first DMS REBOA-equipped forward surgical teams deployed in June 2019. Looking to the future, there is a requirement to develop an assessment of skill retention and the potential need for revalidation.

Do we need medical leadership or medical engagement?

2015 ◽  
Vol 28 (3) ◽  
pp. 173-184 ◽  
Author(s):  
Peter Spurgeon ◽  
Paul Long ◽  
John Clark ◽  
Frank Daly
Keyword(s):  
Care Quality ◽  
Current Evidence ◽  
Organisational Performance ◽  
Content Type ◽  
Care Quality Commission ◽  
The Uk ◽  
Medical Leadership ◽  
First Time ◽  
Practical Implications ◽  
A Current

Purpose – The purpose of this paper is to address issues of medical leadership within health systems and to clarify the associated conceptual issues, for example, leadership versus management and medical versus clinical leadership. However, its principle contribution is to raise the issue of the purpose or outcome of medical leadership, and, in this respect, it argues that it is to promote medical engagement. Design/methodology/approach – The approach is to provide evidence, both from the literature and empirically, to suggest that enhanced medical engagement leads to improved organisational performance and, in doing so, to review the associated concepts. Findings – Building on current evidence from the UK and Australia, the authors strengthen previous findings that effective medical leadership underpins the effective organisational performance. Research limitations/implications – There is a current imbalance between the size of the databases on medical engagement between the UK (very large) and Australia (small but developing). Practical implications – The authors aim to equip medical leaders with the appropriate skill set to promote and enhance greater medical engagement. The focus of leaders in organisations should be in creating a culture that fosters and supports medical engagement. Social implications – This paper provides empowerment of medical professionals to have greater influence in the running of the organisation in which they deliver care. Originality/value – The paper contains, for the first time, linked performance data from the Care Quality Commission in the UK and from Australia with the new set of medical engagement findings.

scholarly journals Comparison of Genotypic and Phenotypic Correlations: Cheverud’s Conjecture in Humans

2018 ◽  
Author(s):  
Sebastian M. Sodini ◽  
Kathryn E. Kemper ◽  
Naomi R. Wray ◽  
Maciej Trzaskowski
Keyword(s):  
Evolutionary Biology ◽  
Genetic Correlations ◽  
Accurate Estimation ◽  
Human Populations ◽  
Phenotypic Correlations ◽  
Recent Developments ◽  
Genotypic And Phenotypic Correlations ◽  
Genetic And Phenotypic Correlations ◽  
Selected Traits ◽  
The Uk

AbstractAccurate estimation of genetic correlation requires large sample sizes and access to genetically informative data, which are not always available. Accordingly, phenotypic correlations are often assumed to reflect genotypic correlations in evolutionary biology. Cheverud’s conjecture asserts that the use of phenotypic correlations as proxies for genetic correlations is appropriate. Empirical evidence of the conjecture has been found across plant and animal species, with results suggesting that there is indeed a robust relationship between the two. Here, we investigate the conjecture in human populations, an analysis made possible by recent developments in availability of human genomic data and computing resources. A sample of 108,035 British European individuals from the UK Biobank was split equally into discovery and replication datasets. 17 traits were selected based on sample size, distribution and heritability. Genetic correlations were calculated using linkage disequilibrium score regression applied to the genome-wide association summary statistics of pairs of traits, and compared within and across datasets. Strong and significant correlations were found for the between-dataset comparison, suggesting that the genetic correlations from one independent sample were able to predict the phenotypic correlations from another independent sample within the same population. Designating the selected traits as morphological or non-morphological indicated little difference in correlation. The results of this study support the existence of a relationship between genetic and phenotypic correlations in humans. This finding is of specific interest in anthropological studies, which use measured phenotypic correlations to make inferences about the genetics of ancient human populations.

scholarly journals EFFECTS OF POPULATION SIZE AND SELECTION INTENSITY ON RESPONSES TO DISRUPTIVE SELECTION IN DROSOPHILA MELANOGASTER

Genetics ◽  
1974 ◽  
Vol 78 (2) ◽  
pp. 715-735
Author(s):  
J S F Barker ◽  
L J E Karlsson
Keyword(s):  
Assortative Mating ◽  
Random Mating ◽  
Female Parent ◽  
Disruptive Selection ◽  
Lethal Gene ◽  
Selection Intensity ◽  
Bristle Number ◽  
Isolation Index ◽  
Selection Intensities ◽  
High Selection

ABSTRACT Disruptive selection for sternopleural bristle number with opportunity for random mating was done in the four treatment combinations of two population sizes (40 pairs and 8 pairs of selected parents) and two selection intensities (1 in 40 and 1 in 2). In each generation, matings among selected parents were observed in a mating chamber, and progeny collected separately from each female parent. In the high number, high selection intensity treatment, divergence between the high and low parts ceased about generation 11. The isolation index increased rapidly to generation 3, but then fluctuated to termination of the population at generation 17. The overall isolation index was significant, indicating a real tendency to assortative mating. The failure of the isolation index to increase after generation 3 was attributed to lower average mating fitness of high males (due to inbreeding) and reduced receptivity of low females (due to a homozygous lethal gene with a large effect on sternopleural bristle number in heterozygotes). In the two low number treatments, isolation indices fluctuated from generation to generation with no obvious trends, and none of the overall isolation indices were significantly different from zero. The high number, low selection intensity treatment showed very little divergence, and one of the replicates showed, in contrast with expectation and the high number, high selection intensity treatment, a significant tendency to disassortative mating. Intense disruptive selection may lead to assortative mating.

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