scholarly journals Spatial and Temporal Dynamics of Contact Zones Between Chromosomal Races of House Mice, Mus musculus domesticus, on Madeira Island

Genes ◽  
2020 ◽  
Vol 11 (7) ◽  
pp. 748 ◽  
Author(s):  
Joaquim T. Tapisso ◽  
Sofia I. Gabriel ◽  
Ana Mota Cerveira ◽  
Janice Britton-Davidian ◽  
Guila Ganem ◽  
...  
Keyword(s):  
Contact Zone ◽  
Temporal Dynamics ◽  
Significant Shift ◽  
Mus Musculus Domesticus ◽  
Landscape Resistance ◽  
Sampling Area ◽  
Contact Zones ◽  
Madeira Island ◽  
The North ◽  
Chromosomal Races

Analysis of contact zones between parapatric chromosomal races can help our understanding of chromosomal divergence and its influence on the speciation process. Monitoring the position and any movement of contact zones can allow particular insights. This study investigates the present (2012–2014) and past (1998–2002) distribution of two parapatric house mouse chromosomal races—PEDC (Estreito da Calheta) and PADC (Achadas da Cruz)—on Madeira Island, aiming to identify changes in the location and width of their contact. We also extended the 1998–2002 sampling area into the range of another chromosomal race—PLDB (Lugar de Baixo). Clinal analysis indicates no major geographic alterations in the distribution and chromosomal characteristics of the PEDC and PADC races but exhibited a significant shift in position of the Rb (7.15) fusion, resulting in the narrowing of the contact zone over a 10+ year period. We discuss how this long-lasting contact zone highlights the role of landscape on mouse movements, in turn influencing the chromosomal characteristics of populations. The expansion of the sampling area revealed new chromosomal features in the north and a new contact zone in the southern range involving the PEDC and PLDB races. We discuss how different interacting mechanisms (landscape resistance, behaviour, chromosomal incompatibilities, meiotic drive) may help to explain the pattern of chromosomal variation at these contacts between chromosomal races.

scholarly journals Landscape resistance constrains hybridization across contact zones in a reproductively and morphologically polymorphic salamander

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Guillermo Velo-Antón ◽  
André Lourenço ◽  
Pedro Galán ◽  
Alfredo Nicieza ◽  
Pedro Tarroso
Keyword(s):  
Contact Zone ◽  
Environmental Heterogeneity ◽  
Evolutionary Dynamics ◽  
Morphological Differentiation ◽  
Phenotypic Traits ◽  
Hybrid Zones ◽  
Landscape Resistance ◽  
Phenotypic Differentiation ◽  
Contact Zones

AbstractExplicitly accounting for phenotypic differentiation together with environmental heterogeneity is crucial to understand the evolutionary dynamics in hybrid zones. Species showing intra-specific variation in phenotypic traits that meet across environmentally heterogeneous regions constitute excellent natural settings to study the role of phenotypic differentiation and environmental factors in shaping the spatial extent and patterns of admixture in hybrid zones. We studied three environmentally distinct contact zones where morphologically and reproductively divergent subspecies of Salamandra salamandra co-occur: the pueriparous S. s. bernardezi that is mostly parapatric to its three larviparous subspecies neighbours. We used a landscape genetics framework to: (i) characterise the spatial location and extent of each contact zone; (ii) assess patterns of introgression and hybridization between subspecies pairs; and (iii) examine the role of environmental heterogeneity in the evolutionary dynamics of hybrid zones. We found high levels of introgression between parity modes, and between distinct phenotypes, thus demonstrating the evolution to pueriparity alone or morphological differentiation do not lead to reproductive isolation between these highly divergent S. salamandra morphotypes. However, we detected substantial variation in patterns of hybridization across contact zones, being lower in the contact zone located on a topographically complex area. We highlight the importance of accounting for spatial environmental heterogeneity when studying evolutionary dynamics of hybrid zones.

scholarly journals Genic differentiation and origin of Robertsonian populations of the house mouse (Mus musculus domesticus Rutty)

1989 ◽  
Vol 53 (1) ◽  
pp. 29-44 ◽  
Author(s):  
Janice Britton-Davidian ◽  
Joseph H. Nadeau ◽  
Henri Croset ◽  
Louis Thaler
Keyword(s):  
Gene Flow ◽  
House Mouse ◽  
Mus Musculus ◽  
Western Europe ◽  
Chromosomal Rearrangements ◽  
Nuclear Gene ◽  
Electrophoretic Analysis ◽  
Mus Musculus Domesticus ◽  
Effective Population ◽  
Chromosomal Races

SummaryThis paper examines the relation between chromosomal and nuclear-gene divergence in 28 wild populations of the house mouse semi-species, Mus musculus domesticus, in Western Europe and North Africa. Besides describing the karyotypes of 15 of these populations and comparing them to those of 13 populations for which such information was already known, it reports the results of an electrophoretic survey of proteins encoded by 34 nuclear loci in all 28 populations. Karyotypic variation in this taxon involves only centric (or Robertsonian) fusions which often differ in arm combination and number between chromosomal races. The electrophoretic analysis showed that the amount of genic variation within Robertsonian (Rb) populations was similar to that for all-acrocentric populations, i.e. bearing the standard karyotype. Moreover, divergence between the two types of populations was extremely low. These results imply that centric fusions in mice have not modified either the level or the nature of genic variability. The genetic similarity between Rb and all-acrocentric populations is not attributed to the persistence of gene flow, since multiple fusions cause marked reproductive isolation. Rather, we attribute this extreme similarity to the very recent origin of chromosomal races in Europe. Furthermore, genic diversity measures suggest that geographically separated Rb populations have in situ and independent origins. Thus, Rb translocations are probably not unique events, but originated repeatedly. Two models are presented to explain how the rapid fixation of a series of chromosomal rearrangements can occur in a population without lowering variability in the nuclear genes. The first model assumes that chromosomal mutation rates are between 10−3 and 10−4 and that populations underwent a series of transient bottlenecks in which the effective population size did not fall below 35. In the second model, genic variability is restored following severe bottlenecks, through gene flow and recombination.

scholarly journals Reduced Wet-Season Length Detected by Satellite Retrievals of Cloudiness over Brazilian Amazonia: A New Methodology

2018 ◽  
Vol 31 (24) ◽  
pp. 9941-9964 ◽  
Author(s):  
Elisa T. Sena ◽  
M. A. F. Silva Dias ◽  
L. M. V. Carvalho ◽  
P. L. Silva Dias
Keyword(s):  
Rainy Season ◽  
Cloud Cover ◽  
Amazon Basin ◽  
Warm Pool ◽  
Cloud Fraction ◽  
Heat Fluxes ◽  
Significant Shift ◽  
Season Length ◽  
Wet Season ◽  
The North

This study investigates the variability of the seasonal cycle of convection in the Brazilian Amazon basin during the last decades, and examines physical mechanisms that potentially trigger these modifications. A new methodology to evaluate the onset and length of the rainy season using long-term cloud fraction observations from geostationary satellites is proposed and the connection between cloud cycle variability, surface properties, and thermodynamic and dynamic conditions is explored. The results show that cloud cover has significantly decreased over the last decades. The decline in cloudiness is steeper at 1200 UTC (0800 LT), when a trend of up to −6% decade−1 is observed over the central and eastern Amazon. High-cloud-cover reduction is the major contributor to the observed decline in total cloud fraction. Delayed onsets and a reduction of up to 4 days yr−1 in the northern and central Amazon wet-season length are observed. Correlation analyses indicate that the El Niño phenomenon affects the interannual variability of cloudiness in the Amazon, leading to delayed onset and early demise of the rainy season. The tropical South Atlantic, the Pacific warm pool, and the North Atlantic tripole also play a small, but significant, role in the Amazon’s cloudiness variability. The decrease in cloudiness over the Amazon basin reduces the amount of solar radiation reflected back to space while increasing irradiance at the surface. This local warming alters surface heat fluxes and the atmospheric thermodynamic profile, further affecting cloud development. The strong tendencies reported here indicate a significant shift in the Amazonian hydroclimate during the last few decades.

Latitudinal shift in the timing of flowering of tree species across tropical Africa: insights from field observations and herbarium collections

2020 ◽  
Vol 36 (4) ◽  
pp. 159-173
Author(s):  
Dakis-Yaoba Ouédraogo ◽  
Olivier J. Hardy ◽  
Jean-Louis Doucet ◽  
Steven B. Janssens ◽  
Jan J. Wieringa ◽  
...  
Keyword(s):  
Tree Species ◽  
Central Africa ◽  
Flowering Phenology ◽  
Graphical Analysis ◽  
Dry Season ◽  
Circular Statistics ◽  
Significant Shift ◽  
The North ◽  
Herbarium Data ◽  
Herbarium Collections

AbstractTemporal and spatial patterns in flowering phenology were assessed for eight tropical African tree species. Specifically, the frequency and seasonality of flowering at seven sites in central Africa were determined using field data, graphical analysis and circular statistics. Additionally, spatial variation in the timing of flowering across species range was investigated using herbarium data, analysing the relative influence of latitude, longitude and timing of the dry season with a Bayesian circular generalized linear model. Annual flowering was found for 20 out of the 25 populations studied. For 21 populations located at the north of the climatic hinge flowering was occurring during the dry season. The analysis of herbarium collections revealed a significant shift in the timing of flowering with latitude for E. suaveolens, and with the timing of the dry season for M. excelsa (and to a lesser extent L. alata), with the coexistence of two flowering peaks near the equator where the distribution of monthly rainfall is bimodal. For the other species, none of latitude, longitude or timing of the dry season had an effect on the timing of flowering. Our study highlights the need to identify the drivers of the flowering phenology of economically important African tree species.

scholarly journals Contact zones: Multispecies scholarship throughImperial Eyes

2019 ◽  
Vol 2 (4) ◽  
pp. 712-731 ◽  
Author(s):  
Helen F Wilson
Keyword(s):  
Discourse Analysis ◽  
Contact Zone ◽  
Human Life ◽  
Contact Zones ◽  
Colonial Histories ◽  
The Relationship ◽  
Forms Of Knowledge ◽  
Do So

The contact zone is described as the space of imperial encounter. Against a backdrop of work that has used Mary Louise Pratt's concept of the contact zone to examine culture-making, and destabilize normative understandings of division, distinction, and bordering, the paper interrogates the value of utilizing the concept in multispecies contexts. To do so, the paper considers the relationship between the contact zone and the concept of encounter, noting how they overlap and depart as approaches to questioning embodied difference, colonial histories, and immanent potential. Turning to the BBC documentary series Blue Planet II, the paper uses the concept of the contact zone and discourse analysis to examine its dominant ideas, frontiers of difference, and the means through which alternative geographies are both foreclosed and enabled. It demonstrates how the concept of the contact zone can draw attention to the ocean as the documentary's site of production, where different forms of knowledge, technology, people, elements, and non-human life grapple with each other in conditions of uneven power. In moving between narrative and oceanic contact zones, the paper raises questions about practices of knowledge-making, uneven structures of power, and decipherability, to demonstrate what can be gained from staying with the postcolonial framing of the contact zone as a critical tool of analysis in multispecies scholarship.

scholarly journals Development of monitoring of water bodies ecological status by the example of small lakes in the North-western Ladoga region

2020 ◽  
Vol 163 ◽  
pp. 03002
Author(s):  
Vasiliy Dmitriev ◽  
Svetlana Sedova ◽  
Anastasiia Plenkina ◽  
Viktoriia Khomiakova ◽  
Diana Avdeevich ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Aquatic Ecosystem ◽  
Temporal Dynamics ◽  
Ecological Status ◽  
Component Composition ◽  
Water Bodies ◽  
Factors Affecting ◽  
Ladoga Region ◽  
The North ◽  
North Western

By the example of the Suuri Lake (0.37 km2) situated in the North-Western Ladoga region, modern aspects of monitoring the ecological state of water bodies are generalized, including 1) assessment of the rates of mass transfer processes in water ecosystems and the factors affecting them; 2) assessment of the integrated properties of water bodies and their ecosystems based on hierarchical schemes summarizing information about the state of subsystems and their properties in the form of composite indices. The results of the study in 2019 are visualized. Quantitative estimates of the chemical and biological composition and physical properties of the aquatic ecosystem, mass transfer rates, factors influencing them are obtained; the values of the integral indicators for the subsystem and their properties (productivity, water quality, stability) and the integral indicators of the systems and their integrative properties as a whole (ecological status, ecological wellbeing) are estimated. The temporal dynamics of the processes, component composition and complex properties of the aquatic ecosystem are investigated.

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