scholarly journals Global demographic history of human populations inferred from whole mitochondrial genomes

2018 ◽  
Vol 5 (8) ◽  
pp. 180543 ◽  
Author(s):  
Eleanor F. Miller ◽  
Andrea Manica ◽  
William Amos

The Neolithic transition has led to marked increases in census population sizes across the world, as recorded by a rich archaeological record. However, previous attempts to detect such changes using genetic markers, especially mitochondrial DNA (mtDNA), have mostly been unsuccessful. We use complete mtDNA genomes from over 1700 individuals, from the 1000 Genomes Project Phase 3, to explore changes in populations sizes in five populations for each of four major geographical regions, using a sophisticated coalescent-based Bayesian method (extended Bayesian skyline plots) and mutation rates calibrated with ancient DNA. Despite the power and sophistication of our analysis, we fail to find size changes that correspond to the Neolithic transitions of the study populations. However, we do detect a number of size changes, which tend to be replicated in most populations within each region. These changes are mostly much older than the Neolithic transition and could reflect either population expansion or changes in population structure. Given the amount of migration and population mixing that occurred after these ancient signals were generated, we caution that modern populations will often carry ghost signals of demographic events that occurred far away from their current location.

2020 ◽  
Vol 16 (1) ◽  
pp. 20190560
Author(s):  
Ahmed Eddine ◽  
Rita Gomes Rocha ◽  
Noureddine Mostefai ◽  
Yamna Karssene ◽  
Koen De Smet ◽  
...  

The diffusion of Neolithic technology together with the Holocene Climatic Optimum fostered the spread of human settlements and pastoral activities in North Africa, resulting in profound and enduring consequences for the dynamics of species, communities and landscapes. Here, we investigate the demographic history of the African wolf ( Canis lupaster ), a recently recognized canid species, to understand if demographic trends of this generalist and opportunistic carnivore reflect the increase in food availability that emerged after the arrival of the Neolithic economy in North Africa. We screened nuclear and mitochondrial DNA in samples collected throughout Algeria and Tunisia, and implemented coalescent approaches to estimate the variation of effective population sizes from present to ancestral time. We have found consistent evidence supporting the hypothesis that the African wolf population experienced a meaningful expansion concurring with a period of rapid population expansion of domesticates linked to the advent of agricultural practices.


2014 ◽  
Author(s):  
Sebastian Lippold ◽  
Hongyang Xu ◽  
Albert Ko ◽  
Mingkun Li ◽  
Gabriel Renaud ◽  
...  

To investigate in detail the paternal and maternal demographic histories of humans, we obtained ~500 kb of non-recombining Y chromosome (NRY) sequences and complete mtDNA genome sequences from 623 males from 51 populations in the CEPH Human Genome Diversity Panel (HGDP). Our results: confirm the controversial assertion that genetic differences between human populations on a global scale are bigger for the NRY than for mtDNA; suggest very small ancestral effective population sizes (<100) for the out-of-Africa migration as well as for many human populations; and indicate that the ratio of female effective population size to male effective population size (Nf/Nm) has been greater than one throughout the history of modern humans, and has recently increased due to faster growth in Nf. However, we also find substantial differences in patterns of mtDNA vs. NRY variation in different regional groups; thus, global patterns of variation are not necessarily representative of specific geographic regions.


2010 ◽  
Vol 60 (4) ◽  
pp. 449-465
Author(s):  
Wen Longying ◽  
Zhang Lixun ◽  
An Bei ◽  
Luo Huaxing ◽  
Liu Naifa ◽  
...  

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.


2001 ◽  
Vol 82 (4) ◽  
pp. 693-712 ◽  
Author(s):  
Peter Simmonds

The spread and origins of hepatitis C virus (HCV) in human populations have been the subject of extensive investigations, not least because of the importance this information would provide in predicting clinical outcomes and controlling spread of HCV in the future. However, in the absence of historical and archaeological records of infection, the evolution of HCV and other human hepatitis viruses can only be inferred indirectly from their epidemiology and by genetic analysis of contemporary virus populations. Some information on the history of the latter may be obtained by dating the time of divergence of various genotypes of HCV, hepatitis B virus (HBV) and the non-pathogenic hepatitis G virus (HGV)/GB virus-C (GBV-C). However, the relatively recent times predicted for the origin of these viruses fit poorly with their epidemiological distributions and the recent evidence for species-associated variants of HBV and HGV/GBV-C in a wide range of non-human primates. The apparent conservatism of viruses over long periods implied by these latter observations may be the result of constraints on sequence change peculiar to viruses with single-stranded genomes, or with overlapping reading frames. Large population sizes and intense selection pressures that optimize fitness may be the factors that set virus evolution apart from that of their hosts.


2019 ◽  
Author(s):  
Aude Saint Pierre ◽  
Joanna Giemza ◽  
Matilde Karakachoff ◽  
Isabel Alves ◽  
Philippe Amouyel ◽  
...  

ABSTRACTThe study of the genetic structure of different countries within Europe has provided significant insights into their demographic history and their actual stratification. Although France occupies a particular location at the end of the European peninsula and at the crossroads of migration routes, few population genetic studies have been conducted so far with genome-wide data. In this study, we analyzed SNP-chip genetic data from 2 184 individuals born in France who were enrolled in two independent population cohorts. Using FineStructure, six different genetic clusters of individuals were found that were very consistent between the two cohorts. These clusters match extremely well the geography and overlap with historical and linguistic divisions of France. By modeling the relationship between genetics and geography using EEMS software, we were able to detect gene flow barriers that are similar in the two cohorts and corresponds to major French rivers or mountains. Estimations of effective population sizes using IBDNe program also revealed very similar patterns in both cohorts with a rapid increase of effective population sizes over the last 150 generations similar to what was observed in other European countries. A marked bottleneck is also consistently seen in the two datasets starting in the fourteenth century when the Black Death raged in Europe. In conclusion, by performing the first exhaustive study of the genetic structure of France, we fill a gap in the genetic studies in Europe that would be useful to medical geneticists but also historians and archeologists.


2013 ◽  
Vol 59 (4) ◽  
pp. 458-474 ◽  
Author(s):  
Sen Song ◽  
Shijie Bao ◽  
Ying Wang ◽  
Xinkang Bao ◽  
Bei An ◽  
...  

Abstract Pleistocene climate fluctuations have shaped the patterns of genetic diversity observed in extant species. Although the effects of recent glacial cycles on genetic diversity have been well studied on species in Europe and North America, genetic legacy of species in the Pleistocene in north and northwest of China where glaciations was not synchronous with the ice sheet development in the Northern Hemisphere or or had little or no ice cover during the glaciations’ period, remains poorly understood. Here we used phylogeographic methods to investigate the genetic structure and population history of the chukar partridge Alec-toris chukar in north and northwest China. A 1,152 – 1,154 bp portion of the mtDNA CR were sequenced for all 279 specimens and a total number of 91 haplotypes were defined by 113 variable sites. High levels of gene flow were found and gene flow estimates were greater than 1 for most population pairs in our study. The AMOVA analysis showed that 81% and 16% of the total genetic variability was found within populations and among populations within groups, respectively. The demographic history of chukar was examined using neutrality tests and mismatch distribution analyses and results indicated Late Pleistocene population expansion. Results revealed that most populations of chukar experienced population expansion during 0.027 ? 0.06 Ma. These results are at odds with the results found in Europe and North America, where population expansions occurred after Last Glacial Maximum (LGM, 0.023 to 0.018 Ma). Our results are not consistent with the results from avian species of Tibetan Plateau, either, where species experienced population expansion following the retreat of the extensive glaciation period (0.5 to 0.175 Ma).


2019 ◽  
Author(s):  
Anders Bergström ◽  
Shane A. McCarthy ◽  
Ruoyun Hui ◽  
Mohamed A. Almarri ◽  
Qasim Ayub ◽  
...  

AbstractGenome sequences from diverse human groups are needed to understand the structure of genetic variation in our species and the history of, and relationships between, different populations. We present 929 high-coverage genome sequences from 54 diverse human populations, 26 of which are physically phased using linked-read sequencing. Analyses of these genomes reveal an excess of previously undocumented private genetic variation in southern and central Africa and in Oceania and the Americas, but an absence of fixed, private variants between major geographical regions. We also find deep and gradual population separations within Africa, contrasting population size histories between hunter-gatherer and agriculturalist groups in the last 10,000 years, a potentially major population growth episode after the peopling of the Americas, and a contrast between single Neanderthal but multiple Denisovan source populations contributing to present-day human populations. We also demonstrate benefits to the study of population relationships of genome sequences over ascertained array genotypes. These genome sequences are freely available as a resource with no access or analysis restrictions.


2010 ◽  
Vol 365 (1556) ◽  
pp. 3277-3288 ◽  
Author(s):  
Anne C. Stone ◽  
Fabia U. Battistuzzi ◽  
Laura S. Kubatko ◽  
George H. Perry ◽  
Evan Trudeau ◽  
...  

Here, we report the sequencing and analysis of eight complete mitochondrial genomes of chimpanzees ( Pan troglodytes ) from each of the three established subspecies ( P. t. troglodytes , P. t. schweinfurthii and P. t. verus ) and the proposed fourth subspecies ( P. t. ellioti ). Our population genetic analyses are consistent with neutral patterns of evolution that have been shaped by demography. The high levels of mtDNA diversity in western chimpanzees are unlike those seen at nuclear loci, which may reflect a demographic history of greater female to male effective population sizes possibly owing to the characteristics of the founding population. By using relaxed-clock methods, we have inferred a timetree of chimpanzee species and subspecies. The absolute divergence times vary based on the methods and calibration used, but relative divergence times show extensive uniformity. Overall, mtDNA produces consistently older times than those known from nuclear markers, a discrepancy that is reduced significantly by explicitly accounting for chimpanzee population structures in time estimation. Assuming the human–chimpanzee split to be between 7 and 5 Ma, chimpanzee time estimates are 2.1–1.5, 1.1–0.76 and 0.25–0.18 Ma for the chimpanzee/bonobo, western/(eastern + central) and eastern/central chimpanzee divergences, respectively.


2019 ◽  
Vol 5 (10) ◽  
pp. eaaw9206 ◽  
Author(s):  
Jeffrey P. Spence ◽  
Yun S. Song

Fine-scale rates of meiotic recombination vary by orders of magnitude across the genome and differ between species and even populations. Studying cross-population differences has been stymied by the confounding effects of demographic history. To address this problem, we developed a demography-aware method to infer fine-scale recombination rates and applied it to 26 diverse human populations, inferring population-specific recombination maps. These maps recapitulate many aspects of the history of these populations including signatures of the trans-Atlantic slave trade and the Iberian colonization of the Americas. We also investigated modulators of the local recombination rate, finding further evidence that Polycomb group proteins and the trimethylation of H3K27 elevate recombination rates. Further differences in the recombination landscape across the genome and between populations are driven by variation in the gene that encodes the DNA binding protein PRDM9, and we quantify the weak effect of meiotic drive acting to remove its binding sites.


Genetics ◽  
2002 ◽  
Vol 160 (2) ◽  
pp. 753-763 ◽  
Author(s):  
Christian Schlötterer

AbstractWith the availability of completely sequenced genomes, multilocus scans of natural variability have become a feasible approach for the identification of genomic regions subjected to natural and artificial selection. Here, I introduce a new multilocus test statistic, ln RV, which is based on the ratio of observed variances in repeat number at a set of microsatellite loci in two groups of populations. The distribution of ln RV values captures demographic history of the populations as well as variation in microsatellite mutation among loci. Given that microsatellite loci associated with a recent selective sweep differ from the remainder of the genome, they are expected to fall outside of the distribution of neutral ln RV values. The ln RV test statistic is applied to a data set of 94 loci typed in eight non-African and two African human populations.


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