scholarly journals Modeling Continuous Admixture

2015 ◽  
Author(s):  
Ying Zhou ◽  
Hongxiang Qiu ◽  
Shuhua Xu
Keyword(s):  
Computer Simulation ◽  
Gene Flow ◽  
Driving Forces ◽  
Real Data ◽  
Modern Human ◽  
Human Migration ◽  
Population Admixture ◽  
Medical Studies ◽  
Isolated Populations ◽  
History Of

Human migration and human isolation serve as the driving forces of modern human civilization. Recent migrations of long isolated populations has resulted in genetically admixed populations. The history of population admixture is generally complex; however, understanding the admixture process is critical to both evolutionary and medical studies. Here, we utilized admixture induced linkage disequilibrium (LD) to infer occurrence of continuous admixture events, which is common for most existing admixed populations. Unlike previous studies, we expanded the typical continuous admixture model to a more general admixture scenario with isolation after a certain duration of continuous gene flow, and we demonstrated that such treatment significantly improved the accuracy of inference under complex admixture scenarios. Based on the extended models, we developed a method based on weighted LD to infer the admixture history considering continuous and complex demographic process of gene flow between populations. We evaluated the performance of the method by computer simulation and applied our method to real data analysis of a few well-known admixed populations.

scholarly journals Modeling Continuous Admixture

2015 ◽  
Author(s):  
Ying Zhou ◽  
Hongxiang Qiu ◽  
Shuhua Xu
Keyword(s):  
Computer Simulation ◽  
Gene Flow ◽  
Driving Forces ◽  
Real Data ◽  
Modern Human ◽  
Human Migration ◽  
Population Admixture ◽  
Medical Studies ◽  
Isolated Populations ◽  
History Of

Human migration and human isolation serve as the driving forces of modern human civilization. Recent migrations of long isolated populations have resulted in genetically admixed populations. The history of population admixture is generally complex; however, understanding the admixture process is critical to both evolutionary and medical studies. Here, we utilized admixture induced linkage disequilibrium (LD) to infer occurrence of continuous admixture events, which is common for most existing admixed populations. Unlike previous studies, we expanded the typical continuous admixture model to a more general admixture scenario with isolation after a certain duration of continuous gene flow. Based on the extended models, we developed a method based on weighted LD to infer the admixture history considering continuous and complex demographic process of gene flow between populations. We evaluated the performance of the method by computer simulation and applied our method to real data analysis of a few well-known admixed populations.

scholarly journals Denisovan ancestry and population history of early East Asians

2020 ◽  
Author(s):  
Diyendo Massilani ◽  
Laurits Skov ◽  
Mateja Hajdinjak ◽  
Byambaa Gunchinsuren ◽  
Damdinsuren Tseveendorj ◽  
...  
Keyword(s):  
Gene Flow ◽  
Human Population ◽  
Modern Human ◽  
Population History ◽  
East Asians ◽  
Aboriginal Australians ◽  
North East ◽  
History Of ◽  
Female Member ◽  
Admixture Event

AbstractWe present analyses of the genome of a ~34,000-year-old hominin skull cap discovered in the Salkhit Valley in North East Mongolia. We show that this individual was a female member of a modern human population that, following the split between East and West Eurasians, experienced substantial gene flow from West Eurasians. Both she and a 40,000-year-old individual from Tianyuan outside Beijing carried genomic segments of Denisovan ancestry. These segments derive from the same Denisovan admixture event(s) that contributed to present-day mainland Asians but are distinct from the Denisovan DNA segments in present-day Papuans and Aboriginal Australians.

scholarly journals Selecting among Alternative Scenarios of Human Evolution by Simulated Genetic Gradients

Genes ◽  
2018 ◽  
Vol 9 (10) ◽  
pp. 506 ◽  
Author(s):  
Catarina Branco ◽  
Miguel Arenas
Keyword(s):  
Human Evolution ◽  
Simulated Data ◽  
Real Data ◽  
Population Admixture ◽  
Evolutionary Processes ◽  
Long Distance ◽  
History Of ◽  
Pros And Cons ◽  
Alternative Scenarios ◽  
And Migration

Selecting among alternative scenarios of human evolution is nowadays a common methodology to investigate the history of our species. This strategy is usually based on computer simulations of genetic data under different evolutionary scenarios, followed by a fitting of the simulated data with the real data. A recent trend in the investigation of ancestral evolutionary processes of modern humans is the application of genetic gradients as a measure of fitting, since evolutionary processes such as range expansions, range contractions, and population admixture (among others) can lead to different genetic gradients. In addition, this strategy allows the analysis of the genetic causes of the observed genetic gradients. Here, we review recent findings on the selection among alternative scenarios of human evolution based on simulated genetic gradients, including pros and cons. First, we describe common methodologies to simulate genetic gradients and apply them to select among alternative scenarios of human evolution. Next, we review previous studies on the influence of range expansions, population admixture, last glacial period, and migration with long-distance dispersal on genetic gradients for some regions of the world. Finally, we discuss this analytical approach, including technical limitations, required improvements, and advice. Although here we focus on human evolution, this approach could be extended to study other species.

scholarly journals Sporadic Genetic Connectivity among Small Insular Populations of the Rare Geoendemic Plant Caulanthus amplexicaulis var. barbarae (Santa Barbara Jewelflower)

2019 ◽  
Vol 110 (5) ◽  
pp. 587-600
Author(s):  
A Millie Burrell ◽  
Jeffrey H R Goddard ◽  
Paul J Greer ◽  
Ryan J Williams ◽  
Alan E Pepper
Keyword(s):  
Gene Flow ◽  
Genetic Connectivity ◽  
Effective Population ◽  
Evolutionary Potential ◽  
Isolated Populations ◽  
Long Distance ◽  
Population Sizes ◽  
History Of ◽  
Small Set ◽  
Nuclear Microsatellite

Abstract Globally, a small number of plants have adapted to terrestrial outcroppings of serpentine geology, which are characterized by soils with low levels of essential mineral nutrients (N, P, K, Ca, Mo) and toxic levels of heavy metals (Ni, Cr, Co). Paradoxically, many of these plants are restricted to this harsh environment. Caulanthus ampexlicaulis var. barbarae (Brassicaceae) is a rare annual plant that is strictly endemic to a small set of isolated serpentine outcrops in the coastal mountains of central California. The goals of the work presented here were to 1) determine the patterns of genetic connectivity among all known populations of C. ampexlicaulis var. barbarae, and 2) estimate contemporary effective population sizes (Ne), to inform ongoing genomic analyses of the evolutionary history of this taxon, and to provide a foundation upon which to model its future evolutionary potential and long-term viability in a changing environment. Eleven populations of this taxon were sampled, and population-genetic parameters were estimated using 11 nuclear microsatellite markers. Contemporary effective population sizes were estimated using multiple methods and found to be strikingly small (typically Ne < 10). Further, our data showed that a substantial component of genetic connectivity of this taxon is not at equilibrium, and instead showed sporadic gene flow. Several lines of evidence indicate that gene flow between isolated populations is maintained through long-distance seed dispersal (e.g., >1 km), possibly via zoochory.

scholarly journals Denisovan ancestry and population history of early East Asians

Science ◽  
2020 ◽  
Vol 370 (6516) ◽  
pp. 579-583
Author(s):  
Diyendo Massilani ◽  
Laurits Skov ◽  
Mateja Hajdinjak ◽  
Byambaa Gunchinsuren ◽  
Damdinsuren Tseveendorj ◽  
...  
Keyword(s):  
Gene Flow ◽  
Human Population ◽  
Modern Human ◽  
Population History ◽  
East Asians ◽  
Aboriginal Australians ◽  
History Of ◽  
East And West ◽  
Female Member ◽  
Admixture Event

We present analyses of the genome of a ~34,000-year-old hominin skull cap discovered in the Salkhit Valley in northeastern Mongolia. We show that this individual was a female member of a modern human population that, following the split between East and West Eurasians, experienced substantial gene flow from West Eurasians. Both she and a 40,000-year-old individual from Tianyuan outside Beijing carried genomic segments of Denisovan ancestry. These segments derive from the same Denisovan admixture event(s) that contributed to present-day mainland Asians but are distinct from the Denisovan DNA segments in present-day Papuans and Aboriginal Australians.

scholarly journals The evolutionary history of human spindle genes includes back-and-forth gene flow with Neandertals

2021 ◽  
Author(s):  
Stéphane Peyrégne ◽  
Janet Kelso ◽  
Benjamin Marco Peter ◽  
Svante Pääbo
Keyword(s):  
Gene Flow ◽  
Evolutionary History ◽  
Common Ancestor ◽  
Modern Human ◽  
Modern Humans ◽  
Ancestral Gene ◽  
Cytoskeletal Structure ◽  
Spindle Apparatus ◽  
History Of ◽  
Segregation Of Chromosomes

Proteins associated with the spindle apparatus, a cytoskeletal structure that ensures the proper segregation of chromosomes during cell division, experienced an unusual number of amino acid substitutions in modern humans after the split from the ancestors of Neandertals and Denisovans. Here, we analyze the history of these substitutions and show that some of the genes in which they occur may have been targets of positive selection. We also find that the two changes in the kinetochore scaffold 1 (KNL1) protein, previously believed to be specific to modern humans, were present in some Neandertals. We show that the KNL1 gene of these Neandertals shared a common ancestor with present-day Africans about 200,000 years ago due to gene flow from the ancestors (or relatives) of modern humans into Neandertals. Subsequently, some non-Africans inherited this modern human-like gene variant from Neandertals, but none inherited the ancestral gene variants. These results add to the growing evidence of early contacts between modern humans and archaic groups in Eurasia and illustrate the intricate relationships among these groups.

Rapid, Adaptive Human Evolution Facilitated by Admixture in the Americas

2021 ◽  
pp. 122-138
Author(s):  
Emily T. Norris ◽  
Lavanya Rishishwar ◽  
I. King Jordan
Keyword(s):  
Human Evolution ◽  
Adaptive Evolution ◽  
Modern Human ◽  
Human Migration ◽  
Human Populations ◽  
Human Immune System ◽  
Isolated Populations ◽  
Adaptive Introgression ◽  
Physical Isolation ◽  
Source Populations

Humans have migrated from their ancestral homelands in Africa to nearly every part of the world. Human migration is characterized by a recurrent process of physical isolation and genetic diversification followed by admixture, whereby previously isolated populations come together and exchange genes. Admixture results in the introgression of alleles from ancestral source populations into hybrid admixed populations, and introgression can facilitate rapid, adaptive evolution by introducing beneficial alleles at intermediate frequencies. We provide examples of adaptive introgression between archaic and modern human populations and for admixed populations in the Americas, which were formed relatively recently via admixture among African, European, and Indigenous American ancestral populations. Adaptive introgression has had an outsized effect on the human immune system. In light of the ubiquity of admixture in human evolution, we propose that adaptive introgression is a fundamentally important mechanism for driving rapid, adaptive evolution in human populations.

Prehistoric maritime migration in the Pacific islands: an hypothesis of ENSO forcing

The Holocene ◽  
2006 ◽  
Vol 16 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Atholl Anderson ◽  
John Chappell ◽  
Michael Gagan ◽  
Richard Grove
Keyword(s):  
Computer Simulation ◽  
Late Holocene ◽  
Pacific Islands ◽  
Southern Oscillation ◽  
Human Migration ◽  
Long Distance ◽  
Early Computer ◽  
The Pacific ◽  
Maritime Technology ◽  
History Of

Long-distance human migration across the Pacific Ocean occurred during the late Holocene and originated almost entirely in the west. As prevailing tradewinds blow from the east, the mechanisms of prehistoric seafaring have been debated since the sixteenth century. Inadequacies in propositions of accidental or opportunistic drifting on occasional westerlies were exposed by early computer simulation. Experimental voyaging in large, fast, weatherly (windward-sailing) double-canoes, together with computer simulation incorporating canoe performance data and modern, averaged, wind conditions, has supported the traditional notion of intentional passage-making in a widely accepted hypothesis of upwind migration by strategic voyaging. The critical assumption that maritime technology and sailing conditions were effectively the same prehistorically as in the historical and modern records is, however, open to question. We propose here that maritime technology during the late-Holocene migrations did not permit windward sailing, and show that the episodic pattern of initial island colonization, which is disclosed in recent archaeological data, matches periods of reversal in wind direction toward westerlies, as inferred from the millennial-scale history of ENSO (El Niño-Southern Oscillation).

Magistri Legis. Eine Studie zur dogmatischen Funktion im industriellen System

2011 ◽  
Vol 2 (2) ◽  
pp. 69-112
Author(s):  
Pierre Legendre
Keyword(s):  
Social Function ◽  
Modern Human ◽  
Human Behaviour ◽  
Cultural Reproduction ◽  
Industrial System ◽  
The West ◽  
History Of ◽  
History Of Law ◽  
New Look

"Der Beitrag reevaluiert die «dogmatische Funktion», eine soziale Funktion, die mit biologischer und kultureller Reproduktion und folglich der Reproduktion des industriellen Systems zusammenhängt. Indem sie sich auf der Grenze zwischen Anthropologie und Rechtsgeschichte des Westens situiert, nimmt die Studie die psychoanalytische Frage nach der Rolle des Rechts im Verhalten des modernen Menschen erneut in den Blick. </br></br>This article reappraises the dogmatic function, a social function related to biological and cultural reproduction and consequently to the reproduction of the industrial system itself. On the borderline of anthropology and of the history of law – applied to the West – this study takes a new look at the question raised by psychoanalysis concerning the role of law in modern human behaviour. "

ZAANGAŻOWANIA KOŚCIOŁA KATOLICKIEGO NA RZECZ MIGRANTÓW – PRZESŁANKI DOKTRYNALNO-PRAWNE

2017 ◽  
Vol 13 (`1) ◽  
pp. 49-68
Author(s):  
Piotr Wojnicz
Keyword(s):  
Pastoral Care ◽  
Social Integration ◽  
Catholic Church ◽  
Local Community ◽  
Primary Objective ◽  
Human Migration ◽  
Religious Orders ◽  
Important Thing ◽  
History Of ◽  
The Catholic Church

The Catholic Church is naturally associated with migrants and its history and doctrine areinextricably linked with the migration of people. Many of the documents of the Catholic Church referto the history of human migration. The responsibility of the Catholic Church for migrants has deephistorical and theological roots. The Catholic Church sees both the positive and the negative sidesof this phenomenon The pastoral care of migrants is a response to the needs of these people. It doesnot replace the territorial structures. They both work closely together and complement each other.The primary objective of the pastoral care of migrants is to enable migrants to integrate with thelocal community. An important element of these structures are religious orders of men and women.The most important thing for migrants is the Christian attitude of the local community tothem. Church repeatedly stressed the importance of hospitality to migrants. Both human andChristian attitude towards migrants expresses itself in a good reception, which is the main factorin overcoming the inevitable difficulties, preventing opposites and solving various problems. Thisattitude helps to alleviate the problems associated with the process of social integration.

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