Sudden Population Growth Research Articles

First record of invasive Stenochrus portoricensis Chamberlin, 1922 (Arachnida: Schizomida: Hubbardiidae) from the Southern region of Brazil

Herein we report for the first time a schizomid for the Southern region of Brazil, Stenochrus portoricensis Chamberlin, 1922 (Schizomida: Hubbardiidae), found in association with termite nests. This is the southernmost record of any schizomid for the Neotropical region. We hypothesize that the species was recently introduced by the sudden population growth of Florianópolis – along with the intense touristic activity – which might have contributed to the inadvertent transportation of this species.

A History of the People's Action Party: 1985–2021 by Shashi Jayakumar

Reviewed by: A History of the People's Action Party: 1985–2021 by Shashi Jayakumar Michael D. Barr A History of the People's Action Party: 1985–2021. By Shashi Jayakumar. Singapore: NUS Press, 2021, 782 pp. ISBN: 978-981-325-128-1 Commissioned institutional histories are generally gentle in their interrogation of their subject matter, but they sometimes offer new and hitherto confidential data that compensate for analytical shyness. Shashi Jayakumar's commissioned history of Singapore's People's Action Party (PAP) definitely qualifies for such praise. Let us begin with the story of the selection of Goh Chok Tong to replace Lee Kuan Yew as prime minister. Page 12 tells us that the choice of Goh was settled at a meeting of 'younger ministers' on 30 December 1984, and the results were conveyed to PM Lee the next day, but two paragraphs down Jayakumar reveals that the results of the meeting had already been written up and submitted to Lee the day before the meeting, on 29 December. So, who really chose Goh as PM-in-waiting, and when? And why does Jayakumar repeat the standard (and false) mythology on pages 94 and 385 (n. 137) as if he had never written page 12? Interestingly, the entry of Lee Hsien Loong into politics in 1984 is also revealed to have been less clear cut than is usually depicted. The official narrative [End Page 130] emphasises that it was Goh Chok Tong (not Lee Kuan Yew) who approached the younger Lee to join politics, with acknowledgement that there were divisions in the Old Guard over his entry. Jayakumar's new sources reveal that Lee Kuan Yew was more involved than is usually thought, especially after opposition began surfacing in Cabinet (pp. 38–43). One of the recurring highlights of the book is revelations of how often Lee Kuan Yew has been given insufficient credit for his achievements. Jayakumar reveals that Lee was the prime mover in the introduction of multi-member Group Representation Constituencies (GRCs) (p. 75), Non-Constituency MPs (NCMPs) (p. 71), the elected presidency (p. 72), Nominated MPs (NMPs) (p. 79), Town Councils (p. 87), and Speakers' Corner (p. 277), even though credit for most of these innovations is usually given to Goh. And when Catherine Lim criticised PM Goh for failing to shake himself free of Lee's dominance in 1994, it was Lee who secretly drove and in part dictated (literally, as it turns out) Goh's counter-attacks (pp. 263–67). Hence, Jayakumar has belatedly confirmed Lim's critique. This does not mean that Goh has no achievements to his name. It was Goh's idea to use HDB (Housing and Development Board) upgrades (and also the supply of kindergarten places!) as incentives for voting PAP and punishments for wards that vote for the opposition (p. 201). Goh also led the charge for reducing government control and agency in Singapore's economy, making it more market- and business-friendly (p. 172). Significantly, however, Jayakumar traces the PAP's subsequent electoral problems back to this ideological U-turn, since it left many Singaporeans wondering if the government really cared much about their welfare any more (p. 189). This popular query was validated when, in 2001, Deputy Prime Minister Lee Hsien Loong dismissed concerns about the social consequences of increasing the numbers of foreign workers (to help business) with the words, 'some other part of Government' will be looking at that (p. 261). Except it seems they didn't. In a masterpiece of understatement and disconnection, Jayakumar reports two chapters later that the housing and transport crises generated by sudden population growth during the 2000s came about because 'there was a reluctance to build ahead of demand' (p. 417). The shift towards openness later spread to the media, arts, culture and the internet (pp. 260–63), but not so much to politics. One of the most remarkable features of the book is the thoroughness and candour with which the author documents the corruption of democracy by the deployment of government resources and state power on behalf of the ruling party (pp. 22–23, 68–70, 127, 177, 188, 194–95, 198, 202, 228, 347, 542–44...

Molecular characterization and phylogeography of Mediterranean picarels (Spicara flexuosa, S. maena and S. smaris) along the coasts of Turkey and the Eastern Mediterranean

In this study, molecular taxonomy associated with Spicara flexuosa, Spicara maena, and Spicara smaris was examined with a geographical focus along the coasts of the Turkey and the Mediterranean. In addition, the effects of the Turkish Straits System on the evolutionary history and phylogeography of Spicara flexuosa were investigated. The mitochondrial cytochrome c oxidase I, cytochrome b, and the nuclear Interphotoreceptor retinoid–binding protein genes were used for these purposes. Our results indicated that the distinction of the three taxa under Spicara is possible with the two different mitochondrial DNA markers. Nuclear DNA analyses indicated that reproductive isolation of the S. maena and S. flexuosa was complete. Demographic analyses support the sudden population growth of S. flexuosa after a potential bottleneck. The result of the dating analyses suggested that the three Spicara species were differentiated during the early or middle Pliocene. An absence of genetic structure between Spicara flexuosa subpopulations from Turkey indicated the connectivity, within sampling locations, suggesting that the Turkish Straits System is a corridor for gene flow for this species. As picarel populations have experienced rapid decline in their distribution areas in recent years, separate population studies are necessary to help make informed conservation and management decisions for S. maena and S. flexuosa.

An ecological settlement design for refugees in Kocaeli

After the civil war in Syria, many refugees sought refuge to Turkey. It brought along many environmental problems such as sudden population growth and resource shortage. It is thought to design an ecological settlement that can produce its own energy and be self-sufficient as a solution due to the limited natural resources, in order to meet the need for shelter quickly in emergency situations. With this in mind, in order to create an ecological settlement, a sample and literature search was conducted and sustainable ecological settlement criteria were determined. As a place operation, the position is preferred in Turkey and that provides employment and by day increasing the number of refugees residing Kocaeli been selected. In line with the ecological settlement criteria, a survey was conducted to understand the accommodation problems and environmental awareness of Syrian refugees living in Kocaeli. Ecological living units are designed in line with the environmental, climatic and sociological data obtained. The units are placed in accordance with the physical environmental conditions of the plot chosen for ecological settlement. In the conclusion part, the applicability of the designed project has been evaluated in line with economic, sociological and ecological criteria and its positive and negative aspects have been discussed.
 In the sample area selected in this study, it is aimed to create an ecological residential area that provides energy, water and raw material conservation in accordance with environmental data, protects the ecosystem, and provides adequate comfort conditions for the users indoors. This study is intended to be a source for ecological settlement projects in order to create livelihoods for low-income groups and to stimulate agriculture, except in emergencies.

The Kvarnbo Hall: Reconsidering the Importance of the Late Iron Age Åland Islands

ABSTRACTThis article accounts for and contextualizes a newly discovered monumental longhouse, a potential hall from the Late Iron Age, on the Åland Islands, Finland. The 45 m long building and its location are discussed in regional and historical context, in comparison to the full data set of coeval houses on Åland, and are argued to signal a social stratification, manifesting a higher level of achievement in this Late Iron Age society. This is further examined in the context of Iron Age settlement development. A rapid and large-scale colonization to Åland, evident in the middle of the first millennium AD, is for the first time explanatorily discussed, addressing the question of why this process occurred. Sudden population growth is linked in part to large-scale climatic disturbances, with fatal consequences in those areas of heavy agricultural dependency, forcing population movement to Åland driven by the presence of maritime resources, particularly seals, and available land.

When the Mediterranean met the Atlantic. A socio-economic view on Early Neolithic communities in central-southern Portugal

The study of the Early Neolithic in Portugal has been receiving increasing attention in the last quarter century, following initial developments in the 1980s that pushed research to new interpretative levels. However, albeit present in some more recent works, reconstructions of social organizational features of these communities have been only marginally attempted. Aiming at providing a first, preliminary view on such issues, it is suggested in this paper that Early Neolithic communities experienced economic (intensive farming exploitation of small plots) and demographic (a sudden population growth followed by decrease and stabilisation) processes as observed elsewhere in Europe. Social inequality is not a permanent trait—likely, these societies went through “ups and downs”, with “ups” occurring after settlement in new areas and “downs” resulting from subsequent fission and dislocation events. Their integration in the broader context of the Neolithic expansion along both rims of the Western Mediterranean is visible not only in shared economic behaviours and options, but also in indirect evidence for maritime transportation of goods. The latter phenomenon also establishes the second half of the 6th millennium BC as the beginning of systematic maritime connections along the Atlantic façade of Europe.

Host-plant dependent population genetics of the invading weevil Hypera postica.

Population genetics of invading pests can be informative for understanding their ecology. In this study, we investigated population genetics of the invasive alfalfa weevil Hypera postica in Fukuoka Prefecture, Japan. We analyzed mitochondrial tRNALeu-COII, nuclear EF-1α gene fragments, and Wolbachia infection in relation to three leguminous host plants: Vicia angustifolia, Vicia villosa, and a new host Astragalus sinicus cultivated as a honey source and green manure crop. A parsimony network generated from mitochondrial gene sequences uncovered two major haplotypic groups, Western and Egyptian. In contrast to reported Wolbachia infection of the Western strain in the United States, none of our analyzed individuals were infected. The absence of Wolbachia may contribute to the stable coexistence of mitochondrial strains through inter-strain reproductive compatibility. Hypera postica genetic variants for the mitochondrial and nuclear genes were associated neither with host plant species nor with two geographic regions (Hisayama and Kama) within Fukuoka. Mitochondrial haplogroups were incongruent with nuclear genetic variants. Genetic diversity at the nuclear locus was the highest for the populations feeding on V. angustifolia. The nuclear data for A. sinicus-feeding populations indicated past sudden population growth and extended Bayesian skyline plot analysis based on the mitochondrial and nuclear data showed that the growth of A. sinicus-feeding population took place within the past 1000 years. These results suggest a shorter history of A. sinicus as a host plant compared with V. angustifolia and a recent rapid growth of H. postica population using the new host A. sinicus.

Microsatellite loci polymorphism of chloroplast DNA of scots pine (Pinus sylvestris L.) in Asia and eastern Europe

The variability of four microsatellite loci of chloroplast DNA was studied in 38 populations of Pinus sylvestris in the European part of Russia, Siberia, Kazakhstan, Transbaikalia and Mongolia. High variability was observed in all regions. In total, 152 haplotypes were identified. The level of population differentiation R(ST) was 2.1%. The differentiation of three geographical groups of populations (European, Siberian-Kazakhstan and Transbaikalian-Mongolian) was insignificant (R(CT) = 0.004%). At the same time, some rare haplotypes were found to be specific for a certain geographical region. Distribution of the rare haplotypes, which differentiated European populations from Asian populations and Mongolian and Transbaikalian populations from the Siberian, showed the independence of the history of these regions. This corresponds more to the hypothesis that the modern areal of Pinus sylvestris originated via settlement from many origins than to the hypothesized single center of the post-boulder-period of recolonization. The distribution of the pair differences between the individual specimens corresponded to the model of sudden population growth. The assessments of the age of this event for Pinus sylvestris (4.5-4.7 million years), which were obtained on the basis of this model, significantly exceeded the age of the quaternary period. Therefore, the revealed growth of populations is hardly due to the changes in flora related with the boulder-period, but rather mirrors the moment of the species formation.

Whole‐genome sequencing of two North American Drosophila melanogaster populations reveals genetic differentiation and positive selection

The prevailing demographic model for Drosophila melanogaster suggests that the colonization of North America occurred very recently from a subset of European flies that rapidly expanded across the continent. This model implies a sudden population growth and range expansion consistent with very low or no population subdivision. As flies adapt to new environments, local adaptation events may be expected. To describe demographic and selective events during North American colonization, we have generated a data set of 35 individual whole-genome sequences from inbred lines of D. melanogaster from a west coast US population (Winters, California, USA) and compared them with a public genome data set from Raleigh (Raleigh, North Carolina, USA). We analysed nuclear and mitochondrial genomes and described levels of variation and divergence within and between these two North American D. melanogaster populations. Both populations exhibit negative values of Tajima's D across the genome, a common signature of demographic expansion. We also detected a low but significant level of genome-wide differentiation between the two populations, as well as multiple allele surfing events, which can be the result of gene drift in local subpopulations on the edge of an expansion wave. In contrast to this genome-wide pattern, we uncovered a 50-kilobase segment in chromosome arm 3L that showed all the hallmarks of a soft selective sweep in both populations. A comparison of allele frequencies within this divergent region among six populations from three continents allowed us to cluster these populations in two differentiated groups, providing evidence for the action of natural selection on a global scale.

Low genetic diversity in wide-spread Eurasian liver fluke Opisthorchis felineus suggests special demographic history of this trematode species.

Opisthorchis felineus or Siberian liver fluke is a trematode parasite (Opisthorchiidae) that infects the hepato-biliary system of humans and other mammals. Despite its public health significance, this wide-spread Eurasian species is one of the most poorly studied human liver flukes and nothing is known about its population genetic structure and demographic history. In this paper, we attempt to fill this gap for the first time and to explore the genetic diversity in O. felineus populations from Eastern Europe (Ukraine, European part of Russia), Northern Asia (Siberia) and Central Asia (Northern Kazakhstan). Analysis of marker DNA fragments from O. felineus mitochondrial cytochrome c oxidase subunit 1 and 3 (cox1, cox3) and nuclear rDNA internal transcribed spacer 1 (ITS1) sequences revealed that genetic diversity is very low across the large geographic range of this species. Microevolutionary processes in populations of trematodes may well be influenced by their peculiar biology. Nevertheless, we suggest that lack of population genetics structure observed in O. felineus can be primarily explained by the Pleistocene glacial events and subsequent sudden population growth from a very limited group of founders. Rapid range expansion of O. felineus through Asian and European territories after severe bottleneck points to a high dispersal potential of this trematode species.

Anopheles darlingi (Diptera: Culicidae) in Panama

We report Anopheles darlingi in Darien Province in eastern Panama. Polymerase chain reaction-restriction fragment length polymorphism profiles of the single copy nuclear white gene and sequence comparisons confirmed the presence of 66 specimens of the northern lineage of An. darlingi. The parsimony network depicted 5 CO1 haplotypes in 40 specimens of An. darlingi, which connected through 7-8 mutational steps with sequences from Central and South America. Furthermore, the presence of haplotypes in Biroquera, Darien Province identical to those previously published from northern Colombia suggests that Panamanian samples originated in Colombia. Results of neutrality tests (R(2) and Fu's F(S)) were not significant and the mismatch distribution was multimodal and did not fit the model of sudden population growth. These findings may indicate a long and stable presence of An. darlingi in eastern Panama.

Educational inequalities in mortality among Israeli Jews: Changes over time in a dynamic population

Changes in educational inequalities in mortality in a country that underwent a sudden population growth were examined using two census-based longitudinal studies from Israel (I, 1983–1992, n=152,150 and II, 1995–2004, n=209,125). Relative changes in educational inequalities in mortality were assessed using mortality rates and odds ratios and their corresponding 95% confidence intervals. Decreases in mortality rates and widening relative educational inequalities in mortality were seen over time. Among recent immigrants, educational inequalities in mortality existed but to a lesser degree than for residents. The widening gap (2.5-fold) in cardiovascular disease mortality risks observed for low versus high educated middle-aged women, was particularly alarming. The observed decreasing mortality rates, indicative of a healthier society, alongside widening educational inequalities in mortality indicates uneven changes within the population.

Chloroplast microsatellites reveal colonization and metapopulation dynamics in the Canary Island pine

Chloroplast microsatellites are becoming increasingly popular markers for population genetic studies in plants, but there has been little focus on their potential for demographic inference. In this work the utility of chloroplast microsatellites for the study of population expansions was explored. First, we investigated the power of mismatch distribution analysis and the F(S) test with coalescent simulations of different demographic scenarios. We then applied these methods to empirical data obtained for the Canary Island pine (Pinus canariensis). The results of the simulations showed that chloroplast microsatellites are sensitive to sudden population growth. The power of the F(S) test and accuracy of demographic parameter estimates, such as the time of expansion, were reduced proportionally to the level of homoplasy within the data. The analysis of Canary Island pine chloroplast microsatellite data indicated population expansions for almost all sample localities. Demographic expansions at the island level can be explained by the colonization of the archipelago by the pine, while population expansions of different ages in different localities within an island could be the result of local extinctions and recolonization dynamics. Comparable mitochondrial DNA sequence data from a parasite of P. canariensis, the weevil Brachyderes rugatus, supports this scenario, suggesting a key role for volcanism in the evolution of pine forest communities in the Canary Islands.

Multiple lineages of the mitochondrial DNA introgression fromPungitius pungitius(L.) toPungitius tymensis(Nikolsky)

We applied mitochondrial DNA (mtDNA) restriction fragment length polymorphism analysis to trace the maternal lineages and compare the intrapopulation mtDNA variabilities of two ninespine stickleback species, Pungitius pungitius (L.) and Pungitius tymensis (Nikolsky), in which occasional natural hybridization was detected. mtDNA phylogenies constructed by neighbor-joining and Wagner parsimony methods resolved two divergent clades differing by an average nucleotide divergence of 5.94%. All P. pungitius mtDNA haplotypes fall within a single clade. In contrast, P. tymensis appeared paraphyletic; nine of the 13 mtDNA haplotypes found in P. tymensis were grouped within the P. pungitius clade, but the remaining four were of the other clade. The former nine mtDNA variants were very close to the sympatric P. pungitius mtDNA halotypes. These observations suggest that the nine P. tymensis haplotypes originated and introgressed from sympatric P. pungitius and that the introgressed mtDNA haplotypes have a polyphyletic origin in each region. The high incidences of the mtDNA introgression in northern and central Hokkaido may be due to a warmer climate than that of the other regions. The recipient P. tymensis populations had significantly higher mtDNA variation than those observed in the sympatric donor species populations, suggesting the sudden population growth during or after the mtDNA substitution processes.