The objective of this study was to analyze the genotypic diversity, frequency of serotypes and the detection of mutacins from Streptococcus mutans isolates in caries-free and caries-active individuals. A total of 260 S. mutans isolated from 28 individuals with and without dental caries were subjected to AP-PCR and PCR screening of glucosyltransferase B, mutacin and serotype genes, which showed ...

Ecosystem engineers affect ecological communities by physically modifying the environment. Understanding the factors determining the distribution of engineers offers a powerful predictive tool for community ecology. In this study, we examine whether the goldenrod bunch gall midge (Rhopalomyia solidaginis) functions as an ecosystem engineer in an old-field ecosystem by altering the composition o...

In this work we study how using multiple communicating populations instead of a single panmictic one may help in maintaining diversity during GP runs. After defining suitable genotypic and phenotypic diversity measures, we apply them to three standard test problems. The experimental results indicate that using multiple populations helps in maintaining phenotypic diversity. We hypothesize that t...

One explanation for the success of sexual reproduction is that sex increases the efficacy of natural selection. Recombination and segregation lead to fitness variance among offspring which then offers a wider target for natural selection. Consequently, adaptation to changing environments is accelerated and population mean fitness will increase. We investigated whether low levels of sex are asso...

The genomic era revolutionized evolutionary biology. The enigma of genotypic-phenotypic diversity and biodiversity evolution of genes, genomes, phenomes, and biomes, reviewed here, was central in the research program of the Institute of Evolution, University of Haifa, since 1975. We explored the following questions. (i) How much of the genomic and phenomic diversity in nature is adaptive and pr...

The diversity–stability relationship is the subject of a long-standing debate in ecology, but the genetic component of diversity has seldom been explored. In this study, we analyzed the interplay between genetic diversity and demographic responses to environmental pressures. This analysis included 30 meadows formed by the Mediterranean endemic seagrass, Posidonia oceanica, showing a wide range ...

Sitobion avenae is a major agricultural pest of wheat in China. Using microsatellite markers, we studied the potential gene flow, genetic diversity, genetic differentiation, and genetic structure of seven S. avenae populations from different regions of China (Beijing, Hebei, Henan, Hubei, Jiangsu, Shandong, and Shanxi provinces). The populations from Henan, Shandong, and Jiangsu showed high lev...

All organisms run the gauntlet of Darwinian selection. Poignant examples include microbial pathogens, which must survive and thrive in their hosts. The process of pathogen adaptation to the host is diverse and is now known to involve a panoply of diversity generators, such as sexual/parasexual reproduction, aneuploidy, prions, mutators, telomeric silencing/recombination, and Hsp90 as a capacito...

BACKGROUND Stability is a crucial ecosystem feature gaining particular importance in face of increasing anthropogenic stressors. Biodiversity is considered to be a driving biotic force maintaining stability, and in this study we investigate how different indices of biodiversity affect the stability of communities in varied abiotic (composition of available resources) and biotic (invasion) conte...