scholarly journals Evolutionary dynamics of selfish DNA explains the abundance distribution of genomic subsequences

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Michael Sheinman ◽  
Anna Ramisch ◽  
Florian Massip ◽  
Peter F. Arndt
Author(s):  
Filip Wierzbicki ◽  
Robert Kofler ◽  
Sarah Signor

AbstractSmall RNAs produced from transposable element (TE) rich sections of the genome, termed piRNA clusters, are a crucial component in the genomic defense against selfish DNA. In animals it is thought the invasion of a TE is stopped when a copy of the TE inserts into a piRNA cluster, triggering the production of cognate small RNAs that silence the TE. Despite this importance for TE control, little is known about the evolutionary dynamics of piRNA clusters, mostly because these repeat rich regions are difficult to assemble and compare. Here we establish a framework for studying the evolution of piRNA clusters quantitatively. Previously introduced quality metrics and a newly developed software for multiple alignments of repeat annotations (Manna) allow us to estimate the level of polymorphism segregating in piRNA clusters and the divergence among homologous piRNA clusters. By studying 20 conserved piRNA clusters in multiple assemblies of four Drosophila species we show that piRNA clusters are evolving rapidly. While 70-80% of the clusters are conserved within species, the clusters share almost no similarity between species as closely related as D. melanogaster and D. simulans. Furthermore, abundant insertions and deletions are segregating within the Drosophila species. We show that the evolution of clusters is mainly driven by large insertions of recently active TEs, and smaller deletions mostly in older TEs. The effect of these forces is so rapid that homologous clusters often do not contain insertions from the same TE families.x


2020 ◽  
Vol 17 (10) ◽  
pp. 229-240
Author(s):  
Weijin Jiang ◽  
Sijian Lv ◽  
Yirong Jiang ◽  
Jiahui Chen ◽  
Fang Ye ◽  
...  

Author(s):  
Michael Laver ◽  
Ernest Sergenti

This chapter extends the survival-of-the-fittest evolutionary environment to consider the possibility that new political parties, when they first come into existence, do not pick decision rules at random but instead choose rules that have a track record of past success. This is done by adding replicator-mutator dynamics to the model, according to which the probability that each rule is selected by a new party is an evolving but noisy function of that rule's past performance. Estimating characteristic outputs when this type of positive feedback enters the dynamic model creates new methodological challenges. The simulation results show that it is very rare for one decision rule to drive out all others over the long run. While the diversity of decision rules used by party leaders is drastically reduced with such positive feedback in the party system, and while some particular decision rule is typically prominent over a certain period of time, party systems in which party leaders use different decision rules are sustained over substantial periods.


2019 ◽  
Vol 108 (1) ◽  
pp. 37
Author(s):  
Rajan Amin ◽  
Tim Wacher ◽  
Josef Clifford ◽  
Bernard Ogwoka ◽  
Bernard Risky Agwanda

2020 ◽  
Vol 4 (3(12)) ◽  
pp. 1-15
Author(s):  
Samira Ilgarovna Proshkina ◽  

The work is devoted to an urgent problem — the study of the evolutionary dynamics of web advertising, its assessment and effectiveness, as well as the problem of legal support and security of information systems. The goal is a systematic analysis of web advertising in an unsafe information field, its relevance and criteria for assessing marketing efforts, minimizing risks, maximizing additional profits and image. Research hypothesis — the effectiveness of web advertising is determined by the form of advertising, place of display, location of the block, model of calculation of the advertising campaign. An approach based on the establishment of preferences, partnership between the state and business structures is emphasized. It takes into account the COVID-19 pandemic, a slowdown in the pace and features of the evolution of business companies in self-isolation. The subtasks of influence on the advertising efficiency of the site’s features and web advertising are highlighted. A comprehensive analysis of information and logical security and computational models of web advertising companies was also carried out.


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