scholarly journals Within-island diversification in a passerine bird

2020 ◽  
Vol 287 (1923) ◽  
pp. 20192999 ◽  
Author(s):  
Maëva Gabrielli ◽  
Benoit Nabholz ◽  
Thibault Leroy ◽  
Borja Milá ◽  
Christophe Thébaud
Keyword(s):  
Phylogenetic Analyses ◽  
Large Population ◽  
Population Sample ◽  
Passerine Bird ◽  
Population History ◽  
Hybrid Zones ◽  
Genome Wide ◽  
Genome Wide Data ◽  
History Of

The presence of congeneric taxa on the same island suggests the possibility of in situ divergence, but can also result from multiple colonizations of previously diverged lineages. Here, using genome-wide data from a large population sample, we test the hypothesis that intra-island divergence explains the occurrence of four geographical forms meeting at hybrid zones in the Reunion grey white-eye ( Zosterops borbonicus ), a species complex endemic to the small volcanic island of Reunion. Using population genomic and phylogenetic analyses, we reconstructed the population history of the different forms. We confirmed the monophyly of the complex and found that one of the lowland forms is paraphyletic and basal relative to others, a pattern highly consistent with in situ divergence. Our results suggest initial colonization of the island through the lowlands, followed by expansion into the highlands, which led to the evolution of a distinct geographical form, genetically and ecologically different from the lowland ones. Lowland forms seem to have experienced periods of geographical isolation, but they diverged from one another by sexual selection rather than niche change. Overall, low dispersal capabilities in this island bird combined with both geographical and ecological opportunities seem to explain how divergence occurred at such a small spatial scale.

scholarly journals A dynamic 6,000-year genetic history of Eurasia’s Eastern Steppe

2020 ◽  
Author(s):  
Choongwon Jeong ◽  
Ke Wang ◽  
Shevan Wilkin ◽  
William Timothy Treal Taylor ◽  
Bryan K. Miller ◽  
...  
Keyword(s):  
Bronze Age ◽  
Population History ◽  
Complex Interplay ◽  
Cultural Changes ◽  
Genetic History ◽  
Nomadic Pastoralists ◽  
Eurasian Steppe ◽  
Genome Wide ◽  
Genome Wide Data ◽  
History Of

SummaryThe Eastern Eurasian Steppe was home to historic empires of nomadic pastoralists, including the Xiongnu and the Mongols. However, little is known about the region’s population history. Here we reveal its dynamic genetic history by analyzing new genome-wide data for 214 ancient individuals spanning 6,000 years. We identify a pastoralist expansion into Mongolia ca. 3000 BCE, and by the Late Bronze Age, Mongolian populations were biogeographically structured into three distinct groups, all practicing dairy pastoralism regardless of ancestry. The Xiongnu emerged from the mixing of these populations and those from surrounding regions. By comparison, the Mongols exhibit much higher Eastern Eurasian ancestry, resembling present-day Mongolic-speaking populations. Our results illuminate the complex interplay between genetic, sociopolitical, and cultural changes on the Eastern Steppe.

scholarly journals Reconstructing the Population History of European Romani from Genome-wide Data

2012 ◽  
Vol 22 (24) ◽  
pp. 2342-2349 ◽  
Author(s):  
Isabel Mendizabal ◽  
Oscar Lao ◽  
Urko M. Marigorta ◽  
Andreas Wollstein ◽  
Leonor Gusmão ◽  
...  
Keyword(s):  
Population History ◽  
Genome Wide ◽  
Genome Wide Data ◽  
History Of

scholarly journals Ancient genomic time transect from the Central Asian Steppe unravels the history of the Scythians

2021 ◽  
Vol 7 (13) ◽  
pp. eabe4414
Author(s):  
Guido Alberto Gnecchi-Ruscone ◽  
Elmira Khussainova ◽  
Nurzhibek Kahbatkyzy ◽  
Lyazzat Musralina ◽  
Maria A. Spyrou ◽  
...  
Keyword(s):  
Bronze Age ◽  
Iron Age ◽  
Gene Pools ◽  
Social Rules ◽  
Eurasian Steppe ◽  
Central Asian ◽  
Genome Wide ◽  
Genome Wide Data ◽  
History Of ◽  
First Millennium

The Scythians were a multitude of horse-warrior nomad cultures dwelling in the Eurasian steppe during the first millennium BCE. Because of the lack of first-hand written records, little is known about the origins and relations among the different cultures. To address these questions, we produced genome-wide data for 111 ancient individuals retrieved from 39 archaeological sites from the first millennia BCE and CE across the Central Asian Steppe. We uncovered major admixture events in the Late Bronze Age forming the genetic substratum for two main Iron Age gene-pools emerging around the Altai and the Urals respectively. Their demise was mirrored by new genetic turnovers, linked to the spread of the eastern nomad empires in the first centuries CE. Compared to the high genetic heterogeneity of the past, the homogenization of the present-day Kazakhs gene pool is notable, likely a result of 400 years of strict exogamous social rules.

Phylogeographic structure and gene flow of Himalayan snowcock (Tetraogallus himalayensis)

2010 ◽  
Vol 60 (4) ◽  
pp. 449-465
Author(s):  
Wen Longying ◽  
Zhang Lixun ◽  
An Bei ◽  
Luo Huaxing ◽  
Liu Naifa ◽  
...  
Keyword(s):  
Demographic History ◽  
Phylogenetic Analyses ◽  
Divergence Time ◽  
Population Expansion ◽  
Population History ◽  
Tibet Plateau ◽  
Phylogeographic Structure ◽  
Mitochondrial Cytochrome B ◽  
History Of ◽  
Qinghai Tibet Plateau

AbstractWe have used phylogeographic methods to investigate the genetic structure and population history of the endangered Himalayan snowcock (Tetraogallus himalayensis) in northwestern China. The mitochondrial cytochrome b gene was sequenced of 102 individuals sampled throughout the distribution range. In total, we found 26 different haplotypes defined by 28 polymorphic sites. Phylogenetic analyses indicated that the samples were divided into two major haplogroups corresponding to one western and one eastern clade. The divergence time between these major clades was estimated to be approximately one million years. An analysis of molecular variance showed that 40% of the total genetic variability was found within local populations, 12% among populations within regional groups and 48% among groups. An analysis of the demographic history of the populations suggested that major expansions have occurred in the Himalayan snowcock populations and these correlate mainly with the first and the second largest glaciations during the Pleistocene. In addition, the data indicate that there was a population expansion of the Tianshan population during the uplift of the Qinghai-Tibet Plateau, approximately 2 million years ago.

scholarly journals Genetic legacy of state centralization in the Kuba Kingdom of the Democratic Republic of the Congo

2018 ◽  
Vol 116 (2) ◽  
pp. 593-598 ◽  
Author(s):  
Lucy van Dorp ◽  
Sara Lowes ◽  
Jonathan L. Weigel ◽  
Naser Ansari-Pour ◽  
Saioa López ◽  
...  
Keyword(s):  
Large Scale ◽  
Democratic Republic ◽  
Central Province ◽  
Genome Wide ◽  
Genetic Patterns ◽  
Genetic Impact ◽  
Genome Wide Data ◽  
Republic Of The Congo ◽  
History Of ◽  
State Centralization

Few phenomena have had as profound or long-lasting consequences in human history as the emergence of large-scale centralized states in the place of smaller scale and more local societies. This study examines a fundamental, and yet unexplored, consequence of state formation: its genetic legacy. We studied the genetic impact of state centralization during the formation of the eminent precolonial Kuba Kingdom of the Democratic Republic of the Congo (DRC) in the 17th century. We analyzed genome-wide data from over 690 individuals sampled from 27 different ethnic groups from the Kasai Central Province of the DRC. By comparing genetic patterns in the present-day Kuba, whose ancestors were part of the Kuba Kingdom, with those in neighboring non-Kuba groups, we show that the Kuba today are more genetically diverse and more similar to other groups in the region than expected, consistent with the historical unification of distinct subgroups during state centralization. We also found evidence of genetic mixing dating to the time of the Kingdom at its most prominent. Using this unique dataset, we characterize the genetic history of the Kasai Central Province and describe the historic late wave of migrations into the region that contributed to a Bantu-like ancestry component found across large parts of Africa today. Taken together, we show the power of genetics to evidence events of sociopolitical importance and highlight how DNA can be used to better understand the behaviors of both people and institutions in the past.

scholarly journals Inferring the population history of Tai-Kadai-speaking people and southernmost Han Chinese on Hainan Island by genome-wide array genotyping

2020 ◽  
Vol 28 (8) ◽  
pp. 1111-1123 ◽  
Author(s):  
Guanglin He ◽  
Zheng Wang ◽  
Jianxin Guo ◽  
Mengge Wang ◽  
Xing Zou ◽  
...  
Keyword(s):  
Hainan Island ◽  
Han Chinese ◽  
Population History ◽  
Genome Wide ◽  
History Of

scholarly journals The genomic history of the Iberian Peninsula over the past 8000 years

Science ◽  
2019 ◽  
Vol 363 (6432) ◽  
pp. 1230-1234 ◽  
Author(s):  
Iñigo Olalde ◽  
Swapan Mallick ◽  
Nick Patterson ◽  
Nadin Rohland ◽  
Vanessa Villalba-Mouco ◽  
...  
Keyword(s):  
Iberian Peninsula ◽  
Iron Age ◽  
North Africa ◽  
Eastern Mediterranean ◽  
Hunter Gatherers ◽  
Y Chromosomes ◽  
Genome Wide ◽  
Genome Wide Data ◽  
History Of ◽  
Genetic Substructure

We assembled genome-wide data from 271 ancient Iberians, of whom 176 are from the largely unsampled period after 2000 BCE, thereby providing a high-resolution time transect of the Iberian Peninsula. We document high genetic substructure between northwestern and southeastern hunter-gatherers before the spread of farming. We reveal sporadic contacts between Iberia and North Africa by ~2500 BCE and, by ~2000 BCE, the replacement of 40% of Iberia’s ancestry and nearly 100% of its Y-chromosomes by people with Steppe ancestry. We show that, in the Iron Age, Steppe ancestry had spread not only into Indo-European–speaking regions but also into non-Indo-European–speaking ones, and we reveal that present-day Basques are best described as a typical Iron Age population without the admixture events that later affected the rest of Iberia. Additionally, we document how, beginning at least in the Roman period, the ancestry of the peninsula was transformed by gene flow from North Africa and the eastern Mediterranean.

scholarly journals On the Number of Siblings and p-th Cousins in a Large Population Sample

2017 ◽  
Author(s):  
Vladimir Shchur ◽  
Rasmus Nielsen
Keyword(s):  
Association Studies ◽  
Large Population ◽  
Population Sample ◽  
Genome Wide Association Studies ◽  
Genome Wide ◽  
Asymptotic Expressions ◽  
Fisher Model ◽  
Sampling Fraction ◽  
Close Relatives ◽  
Number Of Individuals

1.AbstractThe number of individuals in a random sample with close relatives in the sample is a quantity of interest when designing Genome Wide Association Studies (GWAS) and other cohort based genetic, and non-genetic, studies. In this paper, we develop expressions for the distribution and expectation of the number of p-th cousins in a sample from a population of size N under two diploid Wright-Fisher models. We also develop simple asymptotic expressions for large values of N. For example, the expected proportion of individuals with at least one p-th cousin in a sample of K individuals, for a diploid dioecious Wright-Fisher model, is approximately 1 − e−(22p−1)K/N. Our results show that a substantial fraction of individuals in the sample will have at least a second cousin if the sampling fraction (K/N) is on the order of 10−2. This confirms that, for large cohort samples, relatedness among individuals cannot easily be ignored.

scholarly journals Towards a new history and geography of human genes informed by ancient DNA

2014 ◽  
Author(s):  
Joseph Pickrell ◽  
David Reich
Keyword(s):  
Natural Selection ◽  
Ancient Dna ◽  
Population Replacement ◽  
Local Conditions ◽  
Geographic Locations ◽  
Technological Advances ◽  
Genome Wide ◽  
Human Genes ◽  
Genome Wide Data ◽  
History Of

Genetic information contains a record of the history of our species, and technological advances have transformed our ability to access this record. Many studies have used genome-wide data from populations today to learn about the peopling of the globe and subsequent adaptation to local conditions. Implicit in this research is the assumption that the geographic locations of people today are informative about the geographic locations of their ancestors in the distant past. However, it is now clear that long-range migration, admixture and population replacement have been the rule rather than the exception in human history. In light of this, we argue that it is time to critically re-evaluate current views of the peopling of the globe and the importance of natural selection in determining the geographic distribution of phenotypes. We specifically highlight the transformative potential of ancient DNA. By accessing the genetic make-up of populations living at archaeologically-known times and places, ancient DNA makes it possible to directly track migrations and responses to natural selection.

scholarly journals Killer whale genomes reveal a complex history of recurrent admixture and vicariance

2019 ◽  
Author(s):  
Andrew D. Foote ◽  
Michael D. Martin ◽  
Marie Louis ◽  
George Pacheco ◽  
Kelly M. Robertson ◽  
...  
Keyword(s):  
Evolutionary History ◽  
Killer Whale ◽  
Natural Populations ◽  
Major Axis ◽  
Glacial Cycle ◽  
Genome Wide ◽  
Complex Population ◽  
Genome Wide Data ◽  
History Of ◽  
Global Population

AbstractReconstruction of the demographic and evolutionary history of populations assuming a consensus tree-like relationship can mask more complex scenarios, which are prevalent in nature. An emerging genomic toolset, which has been most comprehensively harnessed in the reconstruction of human evolutionary history, enables molecular ecologists to elucidate complex population histories. Killer whales have limited extrinsic barriers to dispersal and have radiated globally, and are therefore a good candidate model for the application of such tools. Here, we analyse a global dataset of killer whale genomes in a rare attempt to elucidate global population structure in a non-human species. We identify a pattern of genetic homogenisation at lower latitudes and the greatest differentiation at high latitudes, even between currently sympatric lineages. The processes underlying the major axis of structure include high drift at the edge of species’ range, likely associated with founder effects and allelic surfing during post-glacial range expansion. Divergence between Antarctic and non-Antarctic lineages is further driven by ancestry segments with up to four-fold older coalescence time than the genome-wide average; relicts of a previous vicariance during an earlier glacial cycle. Our study further underpins that episodic gene flow is ubiquitous in natural populations, and can occur across great distances and after substantial periods of isolation between populations. Thus, understanding the evolutionary history of a species requires comprehensive geographic sampling and genome-wide data to sample the variation in ancestry within individuals.

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