scholarly journals Phylogeography and population genetics of a widespread cold-adapted ant, Prenolepis imparis

2021 ◽  
Author(s):  
Maria Tonione ◽  
Ke Bi ◽  
Rob Dunn ◽  
Andrea Lucky ◽  
Neil Tsutsui
Keyword(s):  
United States ◽  
Gene Flow ◽  
Population Genetic ◽  
Late Quaternary ◽  
Western United States ◽  
Glacial Cycles ◽  
Cold Adapted ◽  
Contemporary Gene Flow ◽  
Demographic Patterns

Historical climate fluctuations have left genetic signatures on species and populations across North America. Here, we used phylogenetic and population genetic analyses from 1,402 orthologous sequences of 75 individuals obtained through sequencing of Ultraconserved Elements (UCEs) to identify population genetic structure and historical demographic patterns across the range of a widespread, cold-adapted ant, the winter ant, Prenolepis imparis. We relate the genomic patterns to those expected as a result of in situ diversification, maintained connectivity, or recent migration. We recovered five well-supported, genetically isolated clades across the distribution: 1) a basal lineage located in Florida, 2) populations across the southern United States, 3) populations that span the midwestern and northeastern United States, 4) populations from the western United States, and 5) populations in southwestern Arizona and Mexico. Using Bayesian clustering analysis in STRUCTURE and k-means clustering in ADEGENET, we investigated gene flow between these major genetic clades and did not find evidence of gene flow between clades. We did find evidence of localized structure with migration in the western United States clade. High support for five major geographic lineages and lack of evidence of contemporary gene flow indicate in situ diversification across the species’ range, probably influenced by glacial cycles of the late Quaternary.

scholarly journals The stratigraphy of the Neogene-Quaternary succession in the southwest Netherlands from the Schelphoek borehole (42G4-11/42G0022) – a sequence-stratigraphic approach

2007 ◽  
Vol 86 (4) ◽  
pp. 317-332 ◽  
Author(s):  
A.A. Slupik ◽  
F.P. Wesselingh ◽  
A.C. Janse ◽  
J.W.F. Reumer
Keyword(s):  
The Netherlands ◽  
Coastal Area ◽  
Late Quaternary ◽  
Tidal Channel ◽  
The South ◽  
Glacial Cycles ◽  
Sequence Stratigraphic ◽  
The North ◽  
Mammal Fauna

AbstractWe investigate the stratigraphy of Neogene and Quaternary intervals of the Schelphoek borehole (Schouwen, Zeeland, the Netherlands). The Breda Formation (Miocene-Zanclean) contains three sequences separated by hiatuses. The Oosterhout Formation (Zanclean-Piacenzian) contains at least two sequences. This formation is overlain by seven sequences of the Gelasian Maassluis Formation that almost certainly represent glacial cycles. The three lowermost sequences are provisionally assigned to the Praetiglian (MIS 96, MIS 98 and MIS 100). A large hiatus exists between the top of the Maassluis Formation and the base of the late Middle to Late Quaternary succession. Due to extensivein situreworking of older strata (including fossils) at the base of several of the formations, their exact boundaries are difficult to establish. The Neogene succession in the Schelphoek borehole is compared to the stratigraphic successions in the Antwerp area to the south and the Dutch coastal area and continental platform to the north. Finally, the stratigraphic context of the Gelasian (‘Tiglian’) mammal fauna dredged from the bottom of a major tidal channel in the adjacent Oosterschelde is assessed by comparison with the Schelphoek borehole.

scholarly journals Population genetic structure of yellow starthistle (Centaurea solstitialis), a colonizing weed in the western United States

1997 ◽  
Vol 75 (9) ◽  
pp. 1470-1478 ◽  
Author(s):  
Mei Sun
Keyword(s):  
United States ◽  
Genetic Structure ◽  
Population Genetic ◽  
Gene Diversity ◽  
Polymorphic Locus ◽  
Allozyme Variation ◽  
Western United States ◽  
Centaurea Solstitialis ◽  
Yellow Starthistle ◽  
Marginal Population

Yellow starthistle (Centaurea solstitialis L.), a diploid annual native to the Mediterranean region, has rapidly colonized a variety of disturbed habitats in the western United States since its accidental introduction in the mid-19th century. Population genetic attributes were investigated in association with the species' colonizing success. Allozyme electrophoretic surveys were conducted for a total of 22 populations from California, Washington, and Idaho, including the southern and northern extremes of its distribution in the Pacific states. High levels of allozyme variation exist within populations, on average 43% of loci were polymorphic, with 2.88 alleles, a heterozygosity of 0.38, and gene diversity of 0.35 per polymorphic locus. At the species level, 56% of loci were polymorphic, with 2.85 alleles per locus, and the total gene diversity was 0.172. With the exception of a marginal population San Diego, the level of genetic diversity was similarly high in all regions. Lack of interpopulation genetic divergence (GST = 0.095) suggests that majority of the colonial populations were founded by a large number of genotypes and that high levels of gene flow may exist between local populations (Nm = 2.38). Information on genetic structure of the weed populations may aid our understanding of the species' colonizing ability in North America and is important for predicting the effectiveness of biological control program. Key words: allozyme variation, Centaurea solstitialis, population genetics, weed colonization, yellow starthistle.

scholarly journals Characteristics of dust storm events over the western United States

2013 ◽  
Vol 13 (5) ◽  
pp. 14195-14220 ◽  
Author(s):  
H. Lei ◽  
J. X. L. Wang
Keyword(s):  
United States ◽  
Dust Storm ◽  
Dust Storms ◽  
Satellite Observations ◽  
Western United States ◽  
Storm Events ◽  
Cold Fronts ◽  
Deep Blue ◽  
Modis Aod

Abstract. In order to better understand the characteristics of dust storm processes over the western United States, available dust storm events reported by media or recorded by NASA earth observatory are classified into four types based on the prevailing weather systems. Then these four types of dust storm events related to cold fronts, downbursts, tropical disturbances, and cyclogenesis and their selected typical representative events are examined to explore their identifiable characteristics based on in-situ and remote sensing measurements. We find that the key feature of cold front-induced dust storms is their rapid process with strong dust emissions. Events caused by rapid downbursts have the highest rates of emissions. Dust storms due to tropical disturbances show stronger air concentrations of dust and last longer than those caused by cold fronts and downbursts. Finally, dust storms caused by cyclogenesis last the longest. The analysis of particulate matter records also shows that the relative ratio of PM10 (size less than 10 μm) values on dust storm-days to non-dust storm-days is a better indicator of event identification compared to previous established indicators. Moreover, aerosol optical depth (AOD) measurements from both in-situ and satellite datasets allow us to capture dust storm processes. We show that MODIS AOD retrieved from the deep blue data better identify dust storm-affected areas and the spatial extension of event intensity. Our analyses also show that the variability in mass concentrations during dust storm processes captured only by in-situ observations is consistent with the variability in AOD from stationary or satellite observations. The study finally indicates that the combination of in-situ and satellite observations is a better method to fill gaps in dust storm recordings.

Paleoecological and biogeographical implications of late Pleistocene noble marten (Martes americana nobilis) in eastern Washington State, USA

2011 ◽  
Vol 75 (1) ◽  
pp. 176-182 ◽  
Author(s):  
R. Lee Lyman
Keyword(s):  
United States ◽  
Late Quaternary ◽  
Archaeological Site ◽  
First Record ◽  
The United States ◽  
Washington State ◽  
Western United States ◽  
Martes Americana ◽  
Future Research ◽  
Eastern Washington

AbstractA mandible identified as noble marten (Martes americana nobilis) recovered from sediments dating to 11,800 cal yr BP and a humerus identified as M. a. cf. nobilis recovered from sediments dating from 13,100 to 12,500 cal yr BP at the Marmes Rockshelter archaeological site in southeastern Washington represent the first record of this taxon in the state. Mammalian taxa associated with the Marmes Rockshelter noble marten represent a diversity of open mesic habitats corroborating earlier analyses of other records of the noble marten in the western United States and exemplify how paleozoologists determine the ecology and environmental predilections of extinct taxa. The recovery site represents the topographically lowest record of this species in western North America and the farthest north record in the United States. Future research should examine known late-Quaternary Martes spp. remains from British Columbia and Alberta to fill in the 2200-km geographic gap in the known distribution of this taxon between a record in the northern Yukon and those in the western United States, and to refine our knowledge of noble marten paleoecology.

scholarly journals Ocean Currents Drove Genetic Structure of Seven Dominant Mangrove Species Along the Coastlines of Southern China

2021 ◽  
Vol 12 ◽  
Author(s):  
Qifang Geng ◽  
Zhongsheng Wang ◽  
Jianmin Tao ◽  
Megumi K. Kimura ◽  
Hong Liu ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Genetic Differentiation ◽  
South China ◽  
Population Genetic ◽  
Ocean Currents ◽  
Mangrove Species ◽  
Contemporary Gene Flow ◽  
Low Levels ◽  
Oceanic Currents

Mangrove forest ecosystems, which provide important ecological services for marine environments and human activities, are being destroyed worldwide at an alarming rate. The objective of our study was to use molecular data and analytical techniques to separate the effects of historical and contemporary processes on the distribution of mangroves and patterns of population genetic differentiation. Seven mangrove species (Acanthus ilicifolius, Aegiceras corniculatum, Avicennia marina, Bruguiera gymnorrhiza, Kandelia obovata, Lumnitzera racemosa, and Rhizophora stylosa), which are predominant along the coastlines of South China, were genotyped at nuclear (nSSR) and chloroplast (cpSSR) microsatellite markers. We estimated historical and contemporary gene flow, the genetic diversity and population structure of seven mangrove species in China. All of these seven species exhibited few haplotypes, low levels of genetic diversity (HE = 0.160–0.361, with the exception of K. obovata) and high levels of inbreeding (FIS = 0.104–0.637), which may be due to their marginal geographical distribution, human-driven and natural stressors on habitat loss and fragmentation. The distribution patterns of haplotypes and population genetic structures of seven mangrove species in China suggest historical connectivity between populations over a large geographic area. In contrast, significant genetic differentiation [FST = 0.165–0.629 (nSSR); GST = 0.173–0.923 (cpSSR)] indicates that populations of mangroves are isolated from one another with low levels of contemporary gene flow among populations. Our results suggest that populations of mangroves were historically more widely inter-connected and have recently been isolated, likely through a combination of ocean currents and human activities. In addition, genetic admixture in Beibu Gulf populations and populations surrounding Hainan Island and southern mainland China were attributed to asymmetric gene flow along prevailing oceanic currents in China in historical times. Even ocean currents promote genetic exchanges among mangrove populations, which are still unable to offset the effects of natural and anthropogenic fragmentation. The recent isolation and lack of gene flow among populations of mangroves may affect their long-term survival along the coastlines of South China. Our study enhances the understanding of oceanic currents contributing to population connectivity, and the effects of anthropogenic and natural habitat fragmentation on mangroves, thereby informing future conservation efforts and seascape genetics toward mangroves.

New microsatellites revealed strong gene flow among populations of a new outbreak pest, Athetis lepigone (Möschler)

2017 ◽  
Vol 108 (5) ◽  
pp. 636-644 ◽  
Author(s):  
W.-C. Zhu ◽  
J.-T. Sun ◽  
J. Dai ◽  
J.-R. Huang ◽  
L. Chen ◽  
...  
Keyword(s):  
Gene Flow ◽  
Genetic Structure ◽  
Population Genetic Structure ◽  
Population Genetic ◽  
Natural Populations ◽  
Source Area ◽  
Population Genetic Analysis ◽  
Outbreak Area ◽  
Lepidoptera Noctuidae

AbstractAthetis lepigone (Möschler) (Lepidoptera: Noctuidae) is a new outbreak pest in China. Consequently, it is unclear whether the emergence and spread of the outbreak of this pest are triggered by rapid in situ population size increases in each outbreak area, or by immigrants from a potential source area in China. In order to explore the outbreak process of this pest through a population genetics approach, we developed ten novel polymorphic expressed sequence tags (EST)-derived microsatellites. These new microsatellites had moderately high levels of polymorphism in the tested population. The number of alleles per locus ranged from 3 to 19, with an average of 8.6, and the expected heterozygosity ranged from 0.269 to 0.783. A preliminary population genetic analysis using these new microsatellites revealed a lack of population genetic structure in natural populations of A. lepigone. The estimates of recent migration rate revealed strong gene flow among populations. In conclusion, our study developed the first set of EST-microsatellite markers and shed a new light on the population genetic structure of this pest in China.

scholarly journals Observing, Measuring, and Assessing the Consequences of Snow Drought

2021 ◽  
Keyword(s):  
Climate Change ◽  
United States ◽  
Risk Management ◽  
Global Warming ◽  
Warm Season ◽  
Western United States ◽  
The World ◽  
Definition Of ◽  
Freshwater Availability

Abstract Warmer and shorter winters from climate change will reduce snowpacks in most seasonally snow-covered regions of the world, with consequences for freshwater availability in spring and summer when people and ecosystems demand water most. Recent record low snowpacks, such as those in the winters of 2013/14 and 2014/15 in the Western United States, have led to a surge in research on ‘snow droughts,’ which are pointed to as harbingers of global warming that pose significant societal hazards. Yet despite the importance of understanding snow droughts to best prepare for their attendant impacts, the concept remains amorphous, with no agreed-upon definition of what they are, how best to measure them, and how such snow droughts connect to warm-season impacts. These knowledge gaps limit our understanding of the risks posed by snow droughts in the present and future, and thus our preparedness for their differential impacts on freshwater resources. To address these issues, we compile a hemispheric ensemble of in situ, satellite, and reanalysis snowpack datasets. We use this ensemble to evaluate the scientific challenges and uncertainties arising from differences in defining and measuring snow droughts, and identify opportunities to leverage this information to better understand the significance of snow droughts. We show that a clearer quantification of what constitutes a snow drought, including its uncertainties, improves our ability to anticipate costly and disruptive warm-season droughts, which is vital for informing risk management and adaptation to changing snow regimes.

scholarly journals Population Genetic Structure and Chemotype Diversity of Fusarium graminearum Populations from Wheat in Canada and North Eastern United States

Toxins ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 180
Author(s):  
Abbot O. Oghenekaro ◽  
Maria A. Oviedo-Ludena ◽  
Mitra Serajazari ◽  
Xiben Wang ◽  
Maria A. Henriquez ◽  
...  
Keyword(s):  
United States ◽  
Gene Flow ◽  
Genetic Structure ◽  
Fusarium Graminearum ◽  
Population Genetic Structure ◽  
Population Genetic ◽  
Fold Increase ◽  
Eastern United States ◽  
North Eastern ◽  
Chemotype Diversity

Fusarium head blight (FHB) is a major disease in wheat causing severe economic losses globally by reducing yield and contaminating grain with mycotoxins. In Canada, Fusarium graminearum is the principal etiological agent of FHB in wheat, producing mainly the trichothecene mycotoxin, deoxynivalenol (DON) and its acetyl derivatives (15-acetyl deoxynivalenol (15ADON) and 3-acetyl deoxynivalenol (3ADON)). Understanding the population biology of F. graminearum such as the genetic variability, as well as mycotoxin chemotype diversity among isolates is important in developing sustainable disease management tools. In this study, 570 F. graminearum isolates collected from commercial wheat crops in five geographic regions in three provinces in Canada in 2018 and 2019 were analyzed for population diversity and structure using 10 variable number of tandem repeats (VNTR) markers. A subset of isolates collected from the north-eastern United States was also included for comparative analysis. About 75% of the isolates collected in the Canadian provinces of Saskatchewan and Manitoba were 3ADON indicating a 6-fold increase in Saskatchewan and a 2.5-fold increase in Manitoba within the past 15 years. All isolates from Ontario and those collected from the United States were 15ADON and isolates had a similar population structure. There was high gene diversity (H = 0.803–0.893) in the F. graminearum populations in all regions. Gene flow was high between Saskatchewan and Manitoba (Nm = 4.971–21.750), indicating no genetic differentiation between these regions. In contrast, less gene flow was observed among the western provinces and Ontario (Nm = 3.829–9.756) and USA isolates ((Nm = 2.803–6.150). However, Bayesian clustering model analyses of trichothecene chemotype subpopulations divided the populations into two clusters, which was correlated with trichothecene types. Additionally, population cluster analysis revealed there was more admixture of isolates among isolates of the 3ADON chemotypes than among the 15ADON chemotype, an observation that could play a role in the increased virulence of F. graminearum. Understanding the population genetic structure and mycotoxin chemotype variations of the pathogen will assist in developing FHB resistant wheat cultivars and in mycotoxin risk assessment in Canada.

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