scholarly journals Isolation by Distance in Populations with Long-Range Dispersal

2020 ◽  
Author(s):  
Tyler B. Smith ◽  
Daniel B. Weissman

ABSTRACTLimited dispersal results in isolation by distance in spatially structured populations, in which individuals found further apart tend to be less related to each other. Models of populations undergoing short-range dispersal predict a close relation between the distance individuals disperse and the length scale over which two sampled individuals are likely to be closely related. In this work, we study the effect of long jumps on patterns of isolation by distance by replacing the typical short-range dispersal kernel with a long-range, power-law kernel. We find that incorporating long jumps leads to a slower decay of relatedness with distance, and that the quantitative form of this slow decay contains visible signatures of the underlying dispersal process.

Any sample of genes traces back to a single common ancestor. Each gene also has other properties: its sequence, its geographic location and the phenotype and fitness of the organism that carries it. With sexual reproduction, different genes have different genealogies, which gives us much more information, but also greatly complicates population genetic analysis. We review the close relation between the distribution of genealogies and the classic theory of identity by descent in spatially structured populations, and develop a simple diffusion approximation to the distribution of coalescence times in a homogeneous two-dimensional habitat. This shows that when neighbourhood size is large (as in most populations) only a small fraction of pairs of genes are closely related, and only this fraction gives information about current rates of gene flow. The increase of spatial dispersion with lineage age is thus a poor estimator of gene flow. The bulk of the genealogy depends on the long-term history of the population; we discuss ways of inferring this history from the concordance between genealogies across loci.


Nature ◽  
2021 ◽  
Author(s):  
Siyu Chen ◽  
Linda Lee ◽  
Tasmin Naila ◽  
Susan Fishbain ◽  
Annie Wang ◽  
...  

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Roman Sherrod ◽  
Eric C. O’Quinn ◽  
Igor M. Gussev ◽  
Cale Overstreet ◽  
Joerg Neuefeind ◽  
...  

AbstractThe structural response of Dy2TiO5 oxide under swift heavy ion irradiation (2.2 GeV Au ions) was studied over a range of structural length scales utilizing neutron total scattering experiments. Refinement of diffraction data confirms that the long-range orthorhombic structure is susceptible to ion beam-induced amorphization with limited crystalline fraction remaining after irradiation to 8 × 1012 ions/cm2. In contrast, the local atomic arrangement, examined through pair distribution function analysis, shows only subtle changes after irradiation and is still described best by the original orthorhombic structural model. A comparison to Dy2Ti2O7 pyrochlore oxide under the same irradiation conditions reveals a different behavior: while the dysprosium titanate pyrochlore is more radiation resistant over the long-range with smaller degree of amorphization as compared to Dy2TiO5, the former involves more local atomic rearrangements, best described by a pyrochlore-to-weberite-type transformation. These results highlight the importance of short-range and medium-range order analysis for a comprehensive description of radiation behavior.


1977 ◽  
Vol 38 (C7) ◽  
pp. C7-202-C7-206 ◽  
Author(s):  
R. MORET ◽  
M. HUBER ◽  
R. COMÈS

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
R. S. Markiewicz ◽  
J. Lorenzana ◽  
G. Seibold ◽  
A. Bansil
Keyword(s):  

2002 ◽  
Vol 14 (03) ◽  
pp. 273-302 ◽  
Author(s):  
HERIBERT ZENK

We give a short summary on how to combine and extend results of Combes and Hislop [2] (short range Anderson model with additional displacements), Kirsch, Stollmann and Stolz [13] and [14] (long range Anderson model without displacements) to get localization in an energy interval above the infimum of the almost sure spectrum for a continuous multidimensional Anderson model including long range potentials and displacements.


2014 ◽  
Vol 45 (1) ◽  
pp. 33-47 ◽  
Author(s):  
Xue Lin ◽  
Chengguo Wang ◽  
Meijie Yu ◽  
Zhitao Lin ◽  
Yuzhen Liu

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