geographic separation
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2022 ◽  
Author(s):  
Jessica M Blanton ◽  
Logan M Peoples ◽  
Mackenzie E Gerringer ◽  
Caroline M Iacuniello ◽  
Natalya D Gallo ◽  
...  

Hadal snailfishes are the deepest-living fishes in the ocean, inhabiting trenches from depths of ~6,000 to 8,000 m. While the microbial communities in trench environments have begun to be characterized, the microbes associated with hadal megafauna remain relatively unknown. Here, we describe the gut microbiomes of two hadal snailfishes, Pseudoliparis swirei (Mariana Trench) and Notoliparis kermadecensis (Kermadec Trench) using 16S rRNA gene amplicon sequencing. We contextualize these microbiomes with comparisons to the abyssal macrourid Coryphaenoides yaquinae and the continental shelf-dwelling snailfish Careproctus melanurus. The microbial communities of the hadal snailfishes were distinct from their shallower counterparts and were dominated by the same sequences related to the Mycoplasmataceae and Desulfovibrionaceae. These shared taxa indicate that symbiont lineages may have remained similar to the ancestral symbiont since their geographic separation or that they are dispersed between geographically distant trenches and subsequently colonize specific hosts. The abyssal and hadal fishes contained sequences related to known, cultured piezophiles, microbes that grow optimally under high hydrostatic pressure, including Psychromonas, Moritella, and Shewanella. These taxa are adept at colonizing nutrient-rich environments present in the deep ocean, such as on particles and in the guts of hosts, and we hypothesize they could make a dietary contribution to deep-sea fishes by degrading chitin and producing fatty acids. We characterize the gut microbiota within some of the deepest fishes to provide new insight into the diversity and distribution of host-associated microbial taxa and the potential of these animals, and the microbes they harbor, for understanding adaptation to deep-sea habitats.


2021 ◽  
Author(s):  
Fabio Alexandre M.H. Silva ◽  
Bruno A. Bonifacio ◽  
Fabio Oliveira Ferreira ◽  
Fabio Coelho Ramos ◽  
Marcos Aurelio Dias ◽  
...  

Although Distributed Software Development (DSD) has been a growing trend in the software industry, performing requirements management in such conditions implies overcoming new limitations resulting from geographic separation. SIDIA is a Research and Development (R&D) Institute, located in Brazil, responsible for producing improvements on the Android Platform for Samsung Products in all Latin America. As we work in collaboration stakeholders provided by Mobile Network Operators (MNO) from Latin countries, it is common that software requirements be provided by external stakeholders. As such, it is difficult to manage these requirements due to the coordination of many different stakeholders in a distributed setting. In order to minimize the risks, we developed a tool to assist our requirements management and development process. This experience paper explores the experience in designing and deploying a software approach that facilitates (I) Distributed Software Development, (II) minimizes requirements error rate, (III) teams and task allocations and (IV) requirements managements. We also report three lessons learned from adopting automated support in the DDS environment.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Alex H. Nishida ◽  
Howard Ochman

AbstractWild great apes harbor clades of gut bacteria that are restricted to each host species. Previous research shows the evolutionary relationships among several host-restricted clades mirror those of great-ape species. However, processes such as geographic separation, host-shift speciation, and host-filtering based on diet or gut physiology can generate host-restricted bacterial clades and mimic patterns of co-diversification across host species. To gain insight into the distribution of host-restricted taxa, we examine captive great apes living under conditions where sharing of bacterial strains is readily possible. Here, we show that increased sampling of wild and captive apes identifies additional host-restricted lineages whose relationships are not concordant with the host phylogeny. Moreover, the gut microbiomes of captive apes converge through the displacement of strains that are restricted to their wild conspecifics by human-restricted strains. We demonstrate that host-restricted and co-diversifying bacterial strains in wild apes lack persistence and fidelity in captive environments.


Animals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 2381
Author(s):  
Mohammad Shamsul Alam Bhuiyan ◽  
Soo-Hyun Lee ◽  
Sheikh Mohammad Jahangir Hossain ◽  
Gautam Kumar Deb ◽  
Most Farhana Afroz ◽  
...  

Understanding the genetic basis of locally adapted indigenous cattle populations is essential to design appropriate strategies and programs for their genetic improvement and conservation. Here, we report genetic diversity measures, population differentiation, and structure of 218 animals sampled from six indicine cattle populations of Bangladesh. Animals were genotyped with Illumina Bovine SNP50K BeadChip along with genotyped data of 505 individuals included from 19 zebu and taurine breeds worldwide. The principal component analysis (PCA) showed clear geographic separation between taurine and indicine lineages where Bangladeshi indigenous cattle clustered with South Asian zebu populations. However, overlapped clusters in PCA, heterozygosity estimates, and Neighbor-Joining phylogenetic tree analysis revealed weak genetic differentiation among the indigenous cattle populations of Bangladesh. The admixture analysis at K = 5 and 9 suggests distinct genetic structure of the studied populations along with 1 to 4% of taurine ancestry. The effective population size suggested a limited pool of ancestors particularly for Sahiwal and North Bengal Grey cattle. In conclusion, these findings shed insights into the genetic architecture of six indigenous cattle populations of Bangladesh for the first time and suggested as distinct gene pools without potential admixture with zebu or taurine populations.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Wei Wang ◽  
Chunyan Ma ◽  
Longling Ouyang ◽  
Wei Chen ◽  
Ming Zhao ◽  
...  

AbstractIn order to provide valuable guidelines for the conservation of germplasm of Lateolabrax maculatus, the genetic diversity and population structure analysis were evaluated for eight geographic populations along coastal regions of China, using 11 microsatellite DNA markers. The genetic parameters obtained showed that, eight populations can be clustered into two groups, the Northern group and the Southern group, concordant with their geographical positions. The UPGMA tree constructed according to the Nei’s genetic distance along with the structure analysis and discriminant analysis of principal component also supported this result. This might be explained by the geographic separation and the divergent environmental conditions among the populations. It's worth noting that, QD (Qingdao) population from northern area was assigned to the Southern group and showed a close genetic relationship and similar genetic constitution with the southern populations. We speculated that large scales of anthropogenic transportation of wild fries from QD populations to the southern aquaculture areas in history should be the primary cause. The populations from GY (Ganyu), RD (Rudong) and BH (Binhai) had higher genetic diversity and showed limited genetic exchange with other populations, indicating better conservation of the natural resources in these regions. All populations were indicated to have experienced bottleneck events in history.


2021 ◽  
Author(s):  
Liam. Donaldson

The spatial mismatch hypothesis argues that the geographic separation between jobs and housing has an adverse effect on the employment outcomes of ethnic minorities. This research paper tests this assumption for immigrant populations in the Toronto Census Metropolitan Area through mapping, cross tabulation and a generalized ordered logit model to determine whether immigrants are at a disadvantage in both the labour market and in terms of commuting distance when compared with Canadian born residents. The results of this study suggest that immigrants are more likely to live over 5 kilometres away from work and that they experience more difficulty in negotiating longer commutes due to higher unemployment rates, lower median household incomes and a greater reliance on transit. In contrast, Canadians are more likely to make daily commutes of over 15 kilometres, however, they are often more capable than immigrants of travelling these increased distances.


2021 ◽  
Author(s):  
Liam. Donaldson

The spatial mismatch hypothesis argues that the geographic separation between jobs and housing has an adverse effect on the employment outcomes of ethnic minorities. This research paper tests this assumption for immigrant populations in the Toronto Census Metropolitan Area through mapping, cross tabulation and a generalized ordered logit model to determine whether immigrants are at a disadvantage in both the labour market and in terms of commuting distance when compared with Canadian born residents. The results of this study suggest that immigrants are more likely to live over 5 kilometres away from work and that they experience more difficulty in negotiating longer commutes due to higher unemployment rates, lower median household incomes and a greater reliance on transit. In contrast, Canadians are more likely to make daily commutes of over 15 kilometres, however, they are often more capable than immigrants of travelling these increased distances.


2021 ◽  
Author(s):  
Julia Canitz ◽  
Derek S Sikes ◽  
Wayne Knee ◽  
Julia Baumann ◽  
Petra Haftaro ◽  
...  

Coevolution is often considered a major driver of speciation, but evidence for this claim is not always found because diversity might be cryptic. When morphological divergence is low, molecular data are needed to uncover diversity. A taxon for which this holds true are the mites, which are known for their extensive and often cryptic diversity. We studied mites of the genus Poecilochirus that are phoretic on burying beetles (Silphidae: Nicrophorus). Poecilochirus taxonomy is poorly understood. Most studies on this genus focus on the evolutionary ecology of Poecilochirus carabi sensu lato, a complex of at least two biological species. Based on molecular data of 232 specimens from 44 locations worldwide, we identified 24 genetic clusters that may represent species. We estimate that these mites began to diversify during the Paleogene, when the clade containing P. subterraneus branched off and the remaining mites diverged into two further clades. One clade resembles P. monospinosus and P. austroasiaticus. The other clade contains 17 genetic clusters resembling P. carabi s.l.. Among these are P. carabi sensu stricto, P. necrophori, and potentially many additional cryptic species. Our analyses suggest that these clades were formed in the miocene by large-scale geographic separation. Diversification also seems to have happened on a smaller scale, potentially due to adaptation to specific hosts or local abiotic conditions, causing some clusters to specialize on certain beetle species. Our results suggest that biodiversity in this genus was generated by multiple interacting forces shaping the tangled webs of life.


Author(s):  
Elisabeth K. Kraus ◽  
Amparo González-Ferrer

AbstractThis study takes a ‘country-of-origin’ or dissimilation perspective to compare the timing of births and completed fertility of international migrants and of those who stay at origin. In order to disentangle selection effects determining differential fertility behaviour of migrants, other mechanisms explaining migrant fertility (disruption, interrelation of events) are also examined. Furthermore, we take into consideration the prevalence of polygamy in Senegal to enhance our knowledge of migrant fertility in this specific context. For the empirical analysis, we use longitudinal data collected in the framework of the MAFE-Senegal project (Migrations between Africa and Europe), which includes retrospective life histories of non-migrants in Senegal and migrants in France, Italy and Spain. We estimate discrete time hazard models and Poisson regressions for male and female respondents separately to analyse the timing of first and higher-order births as well as completed fertility. The results show a strong disruptive effect of migration on childbearing probabilities for men and women, clearly related to the geographic separation of partners due to the out-migration of the man. Increased birth risks in the first year upon arrival could be observed for migrant women following their husbands to Europe, suggesting an interrelation of migration and fertility events. Regarding completed fertility, migrants have significantly fewer children by the age of 40 compared to their non-migrant counterparts, which among men is largely driven by a strong negative effect of polygamous migrants.


2021 ◽  
Vol 45 ◽  
pp. e75525
Author(s):  
José Antonio Molina

Populations of Isoetes velata were studied in order to provide more information on their habitat and distribution in the Western and Northwestern Iberian Peninsula. Habitat together with morphology of megaspores were used as diagnostic features. The form I. velata subsp. velata f. lereschii is considered here as a synonym of I. velata subsp. asturicense and therefore only two taxa remain within the species: I. velata subsp. velata and I. velata subsp. asturicense. Intermediate individuals have been found in the Western Central System. The differentiation within the I. velata group appears to be the result of gradual genetic divergence after isolation. Palaeobotanical data confirm the presence of I. velata subsp. asturicense in Late Glacial lake sediments in northwestern Spain. Cluster classification of the soft-water vegetation with Isoetes velata subsp. asturicense revealed two main groups in the Spanish Central System. A single association, the Sparganio angustifolii-Callitrichetum fontqueri which includes Iberian Atlantic stands of Sparganium angustifolium and Isoetes velata subsp. asturicense, is here recognized. Besides, a variant of the association with Eleocharis acicularis is identified in shallow temporary waters in the Western Sierra de Gredos.


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