Patterns of genetic divergence and demographic history shed light on island‐mainland population dynamics and melanic plumage evolution in the white‐winged Fairywren

Evolution ◽  
2021 ◽  
Author(s):  
Jennifer Walsh ◽  
Leonardo Campagna ◽  
William E. Feeney ◽  
Jacinta King ◽  
Michael S. Webster
Keyword(s):  
Population Dynamics ◽  
Genetic Divergence ◽  
Demographic History ◽  
Mainland Population ◽  
Shed Light

Analyses of mitogenomic markers shed light on the divergence, population dynamics, and demographic history of Pakistani chickens

2020 ◽  
pp. 1-9
Author(s):  
Sawar Khan ◽  
Ayesha Nisar ◽  
Habib Ahmad ◽  
Sardar Azhar Mehmood ◽  
Muddassar Hameed ◽  
...  
Keyword(s):  
Population Dynamics ◽  
Demographic History ◽  
History Of ◽  
Shed Light

Genome-wide Assessment Elucidates Connectivity and the Evolutionary History of the Highly Dispersive Marine Invertebrate Littoraria Flava (Littorinidae:Gastropoda)

2020 ◽  
Author(s):  
Thainá Cortez ◽  
Rafael Viana Amaral ◽  
Thadeu Sobral-Souza ◽  
Sonia Andrade
Keyword(s):  
Population Dynamics ◽  
Species Distribution ◽  
Marine Invertebrate ◽  
Demographic History ◽  
Population Expansion ◽  
Marine Ecosystems ◽  
Assignment Test ◽  
Niche Modelling ◽  
Marine Gastropod ◽  
Haplotype Networks

Abstract Background: An important goal of population genetics studies in marine ecosystems is understanding how connectivity patterns, both spatial and temporal, are influenced by historical and evolutionary factors. When it comes to dispersion and connectivity in marine ecosystems, the role of historical and evolutionary factors over population dynamics andstructure still remains enigmatic. We evaluated the demographic history and population structure of Littoraria flava, a highly dispersive and widely distributed marine gastropod on the Brazilian intertidal zone, to predict the effects of such factors on intrapopulation divergence. To test the hypotheses that (1) the species has historically high levels of geneflow on a macrogeographic spatial scale and (2) the species distribution in rocky shores consists of subpopulations due to high degrees of environmental heterogeneity, we collected specimens along the Brazilian coastline and combined different sets of genetic markers (mitochondrial DNA, nuclear internal transcribed spacer 2, and single nucleotide polymorphisms) with niche-based modeling to predict species paleodistribution.Results: Low genetic structure was observed along the coastline, and all clustering and migration analyses supported the high gene flow over long distances hypothesis (> 3,000 km). Three genetic clusters were identified by the assignment test, each mostly composed of individuals from the three sampled regions. No fine-scale variation was observed for any location. The neutrality tests and the haplotype networks suggest that L. flava had experienced population bottleneck followed by population expansion. Both paleodistribution and coalescent simulations highlight that expansion events occurred in the Southeastern coastline during the Pleistocene interglacial cycles (21 kya).Conclusions: This is the first study on the South American coast that highlights the demographic history on a marine gastropod based on genomic markers associated with niche modelling. We found that climatic changes since the interglacial periods are potentially relevant drivers for the species distribution in the past. Our findings could enhance the understanding of the population dynamics under an evolutionary view for widely distributed non-model marine organisms.

scholarly journals Scenario Forecasts of Population Dynamics in Some Countries of Sub-Saharan Africa

2020 ◽  
Vol 17 (3) ◽  
pp. 47-57
Author(s):  
Yu. V. Zinkina ◽  
S. G. Shulgin
Keyword(s):  
Population Dynamics ◽  
Birth Rate ◽  
Demographic History ◽  
Sub Saharan Africa ◽  
Population Increase ◽  
African Countries ◽  
The Difference ◽  
Sub Saharan ◽  
In Infants And Children ◽  
Demographic Growth

Purpose. In Sub-Saharan Africa, UN demographers expect the population to nearly double over the next 30 years (2020–2050), increasing by more than 1 billion people. Demographic changes of such speed and scale will undoubtedly have global implications. The purpose of the work is to calculate a number of scenarios of the demographic future for some countries of the region, taking into account specific features and events of African recent demographic history (in contrast to the UN forecasts). We also aim to assess the difference between various scenarios for each country and the attainability of the “optimistic” scenario.Materials and methods. We develop scenario forecasts for population dynamics in a number of African countries. In all scenarios, mortality dynamics corresponds to the “medium” UN forecast. For the birth rate dynamics, two scenarios were simulated: the optimistic one (birth rate goes from current rates to 2.1 children per woman in 20 years, which was observed in Iran; Rwanda and Ethiopia are more or less close to this scenario) and the inertial one (for countries where birth rate declined in 2005–2015, this decline was simulated to continue at the same rate; for countries where birth rate “froze”, two options were modeled; both projected birth rate decline at 0.1 child per woman annually, either starting immediately or after another 10 years).The results show that all scenarios, even the “optimistic” one, forecast a huge population increase in all countries considered (Mozambique, Niger, Nigeria, Tanzania, Uganda, Ethiopia) over the next 30 years. Slow birth rate decline (or prolonged “stagnation” at high levels) parallel to successful mortality reduction (especially in infants and children) accumulated enormous demographic inertia in many countries of Sub-Saharan Africa (to calculate its scope, an additional “provisional” scenario was calculated in the work). The difference between the “inertial” and the “optimistic” reaches the size or even sometimes exceeds the current population of the country. This underlines the importance of the governments’ efforts to curb population growth. Ethiopia proves such efforts.Conclusion. Only in Ethiopia the “inertial” and “optimistic” scenarios almost coincide thanks to demographic growth-reducing efforts undertaken there since the early 1990s; thus, in 2005–2015 the birth rate decreased by 1.3 children per woman. This proves that achieving an “optimistic” scenario is possible in African countries, although with considerable and concentrated efforts.

Molecular Population Genetics

2020 ◽  
pp. 179-224
Author(s):  
Daniel L. Hartl
Keyword(s):  
Population Genetics ◽  
Population Dynamics ◽  
Amino Acid ◽  
Frequency Spectrum ◽  
Demographic History ◽  
Human Populations ◽  
Noncoding Dna ◽  
Molecular Population Genetics ◽  
Amino Acid Divergence ◽  
Site Frequency Spectrum

Chapter 7 is an introduction to molecular population genetics that includes the principal concepts of nucleotide polymorphism and divergence, the site frequency spectrum, and tests of selection and their limitations. Highlighted are rates of nucleotide substitution in coding and noncoding DNA, nucleotide and amino acid divergence between species, corrections for multiple substitutions, and the molecular clock. Discussion of the folded and unfolded site frequency spectrum includes the strengths and limitations of Tajima’s D, Fay and Wu’s H, and other measures. The chapter also discusses an emerging consensus to resolve the celebrated selection–neutrality controversy. It also includes examination of demographic history through the use of ancient DNA with special emphasis on the surprising findings in regard to the ancestral makeup of contemporary human populations. Also discussed are the population dynamics of transposable elements in prokaryotes and eukaryotes.

Whole-genome sequences shed light onto the demographic history and contemporary genetic erosion of free-ranging jaguar (Panthera onca) populations

2021 ◽  
Author(s):  
Gustavo P. Lorenzana ◽  
Henrique V. Figueiró ◽  
Christopher B. Kaelin ◽  
Gregory S. Barsh ◽  
Jeremy Johnson ◽  
...  
Keyword(s):  
Demographic History ◽  
Genetic Erosion ◽  
Whole Genome ◽  
Panthera Onca ◽  
Genome Sequences ◽  
Free Ranging ◽  
Shed Light

scholarly journals Evolutionary history of a relict conifer, Pseudotaxus chienii (Taxaceae), in south-east China during the late Neogene: old lineage, young populations

2019 ◽  
Vol 125 (1) ◽  
pp. 105-117 ◽  
Author(s):  
Yixuan Kou ◽  
Li Zhang ◽  
Dengmei Fan ◽  
Shanmei Cheng ◽  
Dezhu Li ◽  
...  
Keyword(s):  
Dna Sequences ◽  
Genetic Divergence ◽  
Evolutionary History ◽  
Isolation By Distance ◽  
Demographic History ◽  
East China ◽  
Population Divergence ◽  
Isolation By Environment ◽  
Late Neogene ◽  
History Of

Abstract Background and Aims Many monotypic gymnosperm lineages in south-east China paradoxically remain in relict status despite long evolutionary histories and ample opportunities for allopatric speciation, but this paradox has received little attention and has yet to be resolved. Here, we address this issue by investigating the evolutionary history of a relict conifer, Pseudotaxus chienii (Taxaceae). Methods DNA sequences from two chloroplast regions and 14 nuclear loci were obtained for 134 samples. The demographic history was inferred and the contribution of isolation by environment (IBE) in patterning genetic divergence was compared with that of isolation by distance (IBD). Key Results Three genetic clusters were identified. Approximate Bayesian computation analyses showed that the three clusters diverged in the late Pliocene (~3.68 Ma) and two admixture events were detected. Asymmetric gene flow and similar population divergence times (~ 3.74 Ma) were characterized using the isolation with migration model. Neither IBD nor IBE contributed significantly to genetic divergence, and the contribution of IBE was much smaller than that of IBD. Conclusions These results suggest that several monotypic relict gymnosperm lineages like P. chienii in south-east China did not remain in situ and undiversified for millions of years. On the contrary, they have been evolving and the extant populations have become established more recently, having insufficient time to speciate. Our findings provide a new perspective for understanding the formation and evolution of the relict gymnosperm flora of China as well as of the Sino-Japanese Flora.

Patterns of genetic divergence in the Ilyodromus amplicolis lineage (Crustacea, Ostracoda), with descriptions of three new species

Zootaxa ◽  
2017 ◽  
Vol 4318 (1) ◽  
pp. 1 ◽  
Author(s):  
RYLAN SHEARN ◽  
ISA SCHÖN ◽  
KOEN MARTENS ◽  
STUART HALSE ◽  
JOE KRAWIEC ◽  
...  
Keyword(s):  
New Species ◽  
Species Diversity ◽  
Molecular Systematics ◽  
Western Australia ◽  
Genetic Divergence ◽  
Molecular Evidence ◽  
Undescribed Species ◽  
Aquatic Habitats ◽  
Three New Species ◽  
Shed Light

In this study, 13 previously recorded populations of Ilyodromus amplicolis De Deckker, 1981 from temporary aquatic habitats in Western Australia were scanned for undescribed species diversity using morphological and molecular systematics techniques. The study found congruent morphological and molecular evidence for three species that are new to science, all of which are formally described here (I. armacutis n. sp., I. sensaddito n. sp. and I. hiatus n. sp.). The findings shed light on the potential for further undescribed diversity in the genus Ilyodromus Sars, 1894. 

scholarly journals Die Treiber der räumlichen Emergenz und Konzentration der Photovoltaik- Industrie in Deutschland

2015 ◽  
Vol 59 (3) ◽  
Author(s):  
Moritz Breul ◽  
Tom Broekel ◽  
Matthias Brachert
Keyword(s):  
Population Dynamics ◽  
Life Cycle ◽  
Relative Importance ◽  
Beneficial Effects ◽  
Industry Life Cycle ◽  
Regional Concentration ◽  
Early Phases ◽  
Shed Light ◽  
Unique Dataset

The drivers of the spatial emergence and clustering of the photovoltaic industry in Germany. Following the relatedness literature, we explore to what extent related industries influenced the regional emergence of the photovoltaic (PV) industry. In addition, we shed light on factors explaining selective processes of clustering. We particularly argue that generic resources and resources of related activities have been crucial for the regional concentration in early phases of the industry life cycle. With increasing maturity, industry-specific resources became more important. Based on a unique dataset containing population dynamics of the German PV industry, the hypotheses are tested empirically. Our results partially confirm the assumed beneficial effects of related industries for the emergence of the PV industry. Moreover, we observe changes in the relative importance of factors supporting regional concentration, with industry-specific resources becoming dominant as the industry matures.

scholarly journals Slow expanders invade by forming dented fronts in microbial colonies

2022 ◽  
Vol 119 (1) ◽  
pp. e2108653119
Author(s):  
Hyunseok Lee ◽  
Jeff Gore ◽  
Kirill S. Korolev
Keyword(s):  
Invasive Species ◽  
Population Dynamics ◽  
Competitive Advantage ◽  
Experimental Observation ◽  
Spatial Competition ◽  
Host Tissue ◽  
Sector Boundary ◽  
Local Competition ◽  
Mutant Forms ◽  
Shed Light

Most organisms grow in space, whether they are viruses spreading within a host tissue or invasive species colonizing a new continent. Evolution typically selects for higher expansion rates during spatial growth, but it has been suggested that slower expanders can take over under certain conditions. Here, we report an experimental observation of such population dynamics. We demonstrate that mutants that grow slower in isolation nevertheless win in competition, not only when the two types are intermixed, but also when they are spatially segregated into sectors. The latter was thought to be impossible because previous studies focused exclusively on the global competitions mediated by expansion velocities, but overlooked the local competitions at sector boundaries. Local competition, however, can enhance the velocity of either type at the sector boundary and thus alter expansion dynamics. We developed a theory that accounts for both local and global competitions and describes all possible sector shapes. In particular, the theory predicted that a slower on its own, but more competitive, mutant forms a dented V-shaped sector as it takes over the expansion front. Such sectors were indeed observed experimentally, and their shapes matched quantitatively with the theory. In simulations, we further explored several mechanisms that could provide slow expanders with a local competitive advantage and showed that they are all well-described by our theory. Taken together, our results shed light on previously unexplored outcomes of spatial competition and establish a universal framework to understand evolutionary and ecological dynamics in expanding populations.

Widespread Gene Flow Model Explains the Genetic–Morphological Variation in a Giant Water Bug Species Under Fine-Scale Spatial Sampling

2019 ◽  
Vol 113 (3) ◽  
pp. 160-170
Author(s):  
Fabiano Stefanello ◽  
Rodolpho S T Menezes ◽  
José Ricardo I Ribeiro ◽  
Eduardo A B Almeida
Keyword(s):  
Population Dynamics ◽  
Gene Flow ◽  
Morphological Variation ◽  
Flow Model ◽  
Demographic History ◽  
Spatial Sampling ◽  
Fine Scale ◽  
Freshwater Organisms ◽  
History Of ◽  
The Last Glacial

Abstract The population dynamics of freshwater organisms are expected to be related to the connectivity among comparable streams, ponds, or rivers in a patchy habitat. Here, we investigated the population dynamics of the giant water bug, Belostoma angustum Lauck 1964 (Hemiptera: Belostomatidae), in a fine-scale spatial sampling, and evaluated which gene flow model previously described for freshwater organisms could explain the genetic–morphological variation in this species. For these purposes, we evaluated genetic and morphological variations, as well as the demographic history of this freshwater insect. Our genetic analyses showed a lack of geographical structure within B. angustum populations across the evaluated range, concordant with widespread gene flow model. Our findings of the demographic history of B. angustum suggest recent and rapid expansion beginning during the late Pleistocene after the Last Glacial Maximum. Likewise, we did not find geographically structured morphological variation in B. angustum, except for body size. The lack of structure of genetic–morphological variation in B. angustum could be explained by a stepping ponds system resulting in the widespread gene flow detected among populations of this species. The warmer and wetter climatic conditions after the last glacial period may have favored the demographic expansion of B. angustum populations due to the increasing of potential freshwater habitats and food resources. This favorable habitat probably allowed the stepping ponds dispersal mode resulting in the verified geographically unstructured genetic–morphological variation.

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