Geographical and genetic distances among zooplankton populations in a set of interconnected ponds: a plea for using GIS modelling of the effective geographical distance

2001 ◽  
Vol 10 (8) ◽  
pp. 1929-1938 ◽  
Author(s):  
E. Michels ◽  
K. Cottenie ◽  
L. Neys ◽  
K. De Gelas ◽  
P. Coppin ◽  
...  
Keyword(s):  
Genetic Distances ◽  
Geographical Distance ◽  
Gis Modelling ◽  
Interconnected Ponds

scholarly journals Genetic analysis of silver-fir populations in the Beskids

2011 ◽  
Vol 72 (2) ◽  
pp. 115-119 ◽  
Author(s):  
Leon Mejnartowicz
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Genetic Analysis ◽  
Abies Alba ◽  
Genetic Distances ◽  
Silver Fir ◽  
Geographical Distance ◽  
Polymorphic Loci ◽  
Expected Heterozygosity ◽  
Rare Alleles

Twenty-eight isozymic loci were studied in the Beskid Mts., in four populations of common silver-fir (<em>Abies alba</em>): one in Beskid Makowski (BM) and three populations in Beskid Sądecki (BS). Their genetic variation and diversity were analyzed, and Nei's genetic distances between the populations were calculated. The results show that the geographical distance between the BM population and the three BS populations is reflected in genetic distances. The BM population is clearly distinct from the others. It has the lowest genetic diversity (<em>I</em> = <em>0.42</em>), percentage of polymorphic loci <em>(%PoL </em>= <em>64.29</em>) and number of rare alleles (<em>NoRa </em>= <em>5</em>). Besides, the BM population has the highest observed heterozygosity (<em>Ho </em>= <em>0.291</em>), which exceeds the expected heterozygosity (<em>He </em>= <em>0.254</em>), estimated on the basis of the Hardy-Weinberg Principle. On the contrary, BS populations are in the state of equilibrium, which is manifested, in similar values of <em>He </em>= <em>0.262 </em>and <em>Ho </em>= <em>0.264</em>.

A new species of red toad, Schismaderma Smith, 1849 (Anura: Bufonidae), from central Angola

Zootaxa ◽  
2021 ◽  
Vol 5081 (3) ◽  
pp. 301-332
Author(s):  
NINDA L. BAPTISTA ◽  
PEDRO VAZ PINTO ◽  
CHAD KEATES ◽  
SHELLEY EDWARDS ◽  
MARK-OLIVER RÖDEL ◽  
...  
Keyword(s):  
New Species ◽  
Entire Range ◽  
Molecular Data ◽  
Genetic Distances ◽  
Integrative Approach ◽  
Geographical Distance ◽  
Miombo Woodlands ◽  
Advertisement Calls ◽  
Specific Differentiation ◽  
A New Species

A new species of red toad, from the previously monotypic genus Schismaderma, is described. The new species was found in Malanje Province, and seems endemic to central Angola, occurring approximately 500 km west of the closest known records of Schismaderma carens. Unusual adult colouration and geographical distance to remaining S. carens populations suggested specific differentiation. In an integrative approach, we compared the red toads from central Angola with S. carens from across the entire range, including molecular data, morphology of adults and tadpoles, and male advertisement calls. Phylogenetic analysis based on mitochondrial (12S, 16S, COI) and nuclear (CXCR4, RAG1) markers, retrieved the Angolan clade as monophyletic, and revealed intra-specific substructuring among the remaining Schismaderma. Genetic distances supported specific differentiation of the central Angolan material compared with other S. carens. Adults from the new Angolan species have bolder ventral patterning and smaller body size than S. carens. No obvious differences were detected between the tadpoles and the advertisement calls of the two Schismaderma species. This discovery adds to the knowledge of the herpetofauna of the Angolan Miombo woodlands, a poorly understood ecoregion, and likely more biodiverse than previously assumed. The result of past river basin dynamics in central Angola likely led to the evolution of this new species of Schismaderma.  

scholarly journals Population genomics of two invasive mosquitoes (Aedes aegypti and Aedes albopictus) from the Indo-Pacific

2020 ◽  
Author(s):  
Thomas L Schmidt ◽  
Jessica Chung ◽  
Ann-Christin Honnen ◽  
Andrew R Weeks ◽  
Ary A Hoffmann
Keyword(s):  
Genetic Differentiation ◽  
Aedes Albopictus ◽  
Population Genomics ◽  
Genetic Distances ◽  
Geographical Distance ◽  
Pacific Region ◽  
Native Range ◽  
Dengue Transmission ◽  
Transportation Routes ◽  
Human Transport

AbstractThe arbovirus vectors Aedes aegypti (yellow fever mosquito) and Ae. albopictus (Asian tiger mosquito) are both common throughout the Indo-Pacific region, where 70% of global dengue transmission occurs. For Ae. aegypti all Indo-Pacific populations are invasive, having spread from an initial native range of Africa, while for Ae. albopictus the Indo-Pacific includes invasive populations and those from the native range: putatively, India to Japan to Southeast Asia. This study analyses the population genomics of 480 of these mosquitoes sampled from 27 locations in the Indo-Pacific. We investigated patterns of genome-wide genetic differentiation to compare pathways of invasion and ongoing gene flow in both species, and to compare invasive and native-range populations of Ae. albopictus. We also tested landscape genomic hypotheses that genetic differentiation would increase with geographical distance and be lower between locations with high connectivity to human transportation routes, the primary means of dispersal at these scales. We found that genetic distances were generally higher in Ae. aegypti, with Pacific populations the most highly differentiated. The most differentiated Ae. albopictus populations were in Vanuatu, Indonesia and Sri Lanka, the latter two representing potential native-range populations and potential cryptic subspeciation respectively. Genetic distances in Ae. aegypti increased with geographical distance, while in Ae. albopictus they decreased with higher connectivity to human transportation routes. Contrary to the situation in Ae. aegypti, we found evidence of long-distance Ae. albopictus colonisation events, including colonisation of Mauritius from East Asia and of Fiji from Southeast Asia. These direct genomic comparisons indicate likely differences in dispersal ecology in these species, despite their broadly sympatric distributions and similar use of human transport to disperse. Our findings will assist biosecurity operations to trace the source of invasive material and for biocontrol operations that benefit from matching genetic backgrounds of released and local populations.Author SummaryThe mosquitoes Ae. aegypti and Ae. albopictus are highly invasive and transmit dengue and other arboviruses. This study investigates the genetics of these mosquitoes in the Indo-Pacific region, where 70% of global dengue transmission occurs and where both species have established widespread invasions by hitch-hiking on human transport vessels. We compared patterns of genetic differentiation to determine the pathways these species have taken while spreading through the Indo-Pacific, and to better understand how they disperse. We sequenced DNA from 480 mosquitoes sampled from 27 locations in the Indo-Pacific, and found many genetic differences between the two species. Populations of Ae. aegypti, which is not native to the region, tended to be genetically different from each other, and populations in the Pacific Ocean were particularly divergent. Aedes albopictus populations were generally more similar to each other, though genetically different populations in Sri Lanka and Indonesia point to these having a different history to other populations. Genetic differences between Ae. aegypti populations were larger when populations were geographically distant, while differences between Ae. albopictus populations were larger when populations likely had limited access to human transportation. These results will help improve strategies for controlling these species and stopping their spread around the world.

Molecular phylogeny and taxonomic evaluation of the genus Asaccus Dixon and Anderson, 1973 (Reptilia: Phyllodactylidae) in Iran

2020 ◽  
pp. 207-214
Author(s):  
Akbar Fattahi
Keyword(s):  
Molecular Phylogeny ◽  
Nuclear Gene ◽  
Genetic Distances ◽  
Genetic Lineage ◽  
New Taxon ◽  
Zagros Mountains ◽  
Relict Species ◽  
Taxonomical Revision ◽  
Two Populations ◽  
Taxonomic Evaluation

The Iranian species of the phyllodactylid geckos of the genus Asaccus are found only in the valleys of the Zagros Mountains, a region which represents an important area of endemism in western Iran. Recently, many relict species have been described from the central and southern parts of the Zagros Mountains, which were previously known as A. elisae. The recent descriptions of species within this complex suggest that diversity within the genus may be higher than expected and that its taxonomy and systematics should be revised. In the present study, phylogenetic relationships within the genus Asaccus were evaluated using two mitochondrial and one nuclear gene. Genetically, the genus shows high levels of variability. The molecular phylogeny of the genus suggests the presence of three main clades along the Zagros Mountains with the southern population (from the Hormozgan province) and one clade (A. sp8 and A. sp9) being sister taxon to A. montanus from UAE. The remaining samples are separated into two reciprocally monophyletic groups: the northern (Kurdistan, Kermanshah and Ilam provinces) and the central (Lorestan, Khuzestan, Kohgilouye-Bouyer Ahmad and Fars provinces) Zagros groups. The results of the present study suggest that populations attributed to A. elisae in Iran correspond to distinct lineages with high genetic distances. In brief, our results suggest that the genus needs a major taxonomical revision The Arabian origin of the genus has not been confirmed, because two populations from Zagros were located within the A. montanus, A. gallagheri and A. platyrhynchus clade. Further morphological analyses are needed to systematically define each genetic lineage as a new taxon.

“By Degrees”

2020 ◽  
Vol 75 (3) ◽  
pp. 265-293
Author(s):  
Paul Giles
Keyword(s):  
Eighteenth Century ◽  
World Literature ◽  
Local Realism ◽  
Frames Of Reference ◽  
Geographical Distance ◽  
Historical Time ◽  
Time And Space ◽  
Mansfield Park ◽  
Initial Analysis ◽  
Temporal And Spatial

Paul Giles, “‘By Degrees’: Jane Austen’s Chronometric Style of World Literature” (pp. 265–293) This essay considers how Jane Austen’s work relates to “World Literature” by internalizing a chronometric style. Examining the emergence of the chronometer in the eighteenth century, it suggests how Austen drew on nautical frames of reference to combine disparate trajectories of local realism, geographical distance, and historical time. The essay thus argues that Austen’s fiction is interwoven with a reflexive mode of cartographic mapping, one that draws aesthetically on nautical instruments to remap time and space. This style involves charting various fluctuations of perspective that reorder history, memory, and genealogy, while also recalibrating Britain’s position in relation to the wider world. Moving on from an initial analysis of Austen’s juvenilia and early novels, the essay proceeds in its second part to discuss Mansfield Park (1814) in relation to Pacific exploration and trade. In its third part, it considers Emma (1815) in the context of comic distortions and the misreadings that arise from temporal and spatial compressions in the narrative, a form heightened by the novel’s reflexive wordplay. Hence the essay argues that Austen’s particular style of World Literature integrates chronometric cartography with domestic circumstances, an elusive idiom that also manifests itself in relation to the gender dynamics of Persuasion (1817) and the unfinished “Sanditon,” as discussed in the essay’s concluding pages. This is correlated finally with the way Austen’s novels are calibrated, either directly or indirectly, in relation to a global orbit.

Giving Care, Delivering Value

2017 ◽  
Author(s):  
Joia S. Mukherjee
Keyword(s):  
Value Chain ◽  
Barriers To Care ◽  
Care Delivery ◽  
Care Quality ◽  
Patient Knowledge ◽  
Geographical Distance ◽  
Patient Centered ◽  
Utilization Of Services ◽  
The Continuum

People value health. Yet impoverished patients face many barriers in seeking and receiving care. This chapter challenges the hypothesis that low service utilization of services is due to lack of patient knowledge. Rather, the chapter posits that low utilization is due to barriers to care (Quality of care, another factor in low utilization, will be addressed in Chapter 10). The chapter highlights offers the approaches caregiving and accompaniment to help providers and managers understand the geographical distance, harrowing transportation, and financial challenges that patients face. This understanding should support the design of more empathic and patient-centered programs that reduce barriers to care. To that end, this chapter introduces a tool called the care delivery value chain which is a helpful framework to design a system that optimizes access and services across the continuum of care.

scholarly journals PROTEIN POLYMORPHISMS, SEGREGATION IN GENETIC CROSSES AND GENETIC DISTANCES AMONG FISHES OF THE GENUS XIPHOPHORUS (POECILIIDAE)

Genetics ◽  
1982 ◽  
Vol 102 (3) ◽  
pp. 539-556
Author(s):  
Don C Morizot ◽  
Michael J Siciliano
Keyword(s):  
Goodness Of Fit ◽  
Inbred Strains ◽  
Interspecific Backcross ◽  
Genetic Distances ◽  
Rapid Expansion ◽  
Starch Gel Electrophoresis ◽  
Lower Vertebrate ◽  
Protein Coding ◽  
Group I ◽  
Starch Gel

ABSTRACT The products of 49 protein-coding loci were examined by starch gel electrophoresis for populational variation in six species of Xiphophorus fishes and/or segregation in intra- and interspecific backcross and intercross hybrids. Electrophoretic variation was observed for 29 of the 35 locus products in a survey of 42 population samples. The highest frequency of polymorphic loci observed in noninbred populations was 0.143. After ten or more generations of inbreeding, all loci studied were monomorphic. Inbred strains generally exhibited the commonest electrophoretic alleles of the population from which they were derived. An assessment of genetic distances among Xiphophorus populations reflected classical systematic relationships and suggested incipient subspeciation between X. maculatus from different drainages as well as several species groups. Thirty-three loci were analyzed with respect to segregation in hybrids. The goodness of fit of segregations to Mendelian expectations at all loci analyzed (except loci in linkage group I) is interpreted as evidence for high genetic compatibility of the genomes of Xiphophorus species. It is anticipated that these data will result in a rapid expansion of the assignment of protein-coding loci to linkage groups in these lower vertebrate species.

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