In bacteria, horizontal gene transfer (HGT) is widely recognized as the mechanism responsible for the widespread distribution of antibiotic resistance genes, gene clusters encoding biodegradative pathways and pathogenicity determinants. We propose that HGT is also responsible for speciation and sub-speciation in bacteria, and that HGT mechanisms exist in eukaryotes.

BACKGROUND In the present study we have investigated the cultural transmission of two types of traditional plant knowledge in two communities of North-western Patagonia, Argentina. In the Pilcaniyeu community, we studied the transmission of traditional knowledge related to horticultural practices in home-gardens, greenhouses and gardens; while in the community of Cuyin Manzano, we studied wild ...

We investigate the selective forces that promote the emergence of modularity in nature. We demonstrate the spontaneous emergence of modularity in a population of individuals that evolve in a changing environment. We show that the level of modularity correlates with the rapidity and severity of environmental change. The modularity arises as a synergistic response to the noise in the environment ...

A group of retinal interneurons known as horizontal cells has recently been shown to exhibit a variety of unique biological properties, as compared with other nerve cells, that challenge many long-standing assumptions in the fields of neural development and cancer biology. These features include their unusual migratory behavior, their unique morphological plasticity, and their propensity to div...

Bacteria’s ability to pass entire genes between one another, a process called Horizontal Gene Transfer (HGT), has a major impact on bacterial evolution. In an ongoing project at Harvey Mudd, computational methods have been used to catalogue the HGT events that have impacted a group of closely related bacteria. This thesis builds on that project, by improving our ability to identify gene familie...

It is generally accepted that resistance genes acquired by human pathogens through horizontal gene transfer originated in environmental, non-pathogenic bacteria. As a consequence, there is increasing concern on the roles that natural, non-clinical ecosystems, may play in the evolution of resistance. Recent studies have shown that the variability of determinants that can provide antibiotic resis...

Streptococcus mutans strains were isolated from cohorts of Brazilian nursery school children and genotyped by arbitrarily primed PCR and restriction fragment length polymorphism analysis. Of 24 children with two to five S. mutans isolates, 29% carried two or more genotypes. The presence of matching genotypes of S. mutans among children attending one nursery suggests horizontal transmission.

The three relevant solutions of these equations are (i) (N T , N ∗ A) = (0, 0): this is the trivial case where both populations are zero. (ii) (N T , N ∗ A) = (K, 0): this solution describes a domain full with individuals that do not carry the trait; no trait-carrying individuals are present. (iii) (N T , N ∗ A) = (K,K − β/γ): this solution is the most interesting one for our purposes. It descr...

Horizontal gene transfer (HGT) is the movement of genetic information between organisms, a process that includes the spread of antibiotic resistance genes among bacteria (except for those from parent to offspring), fueling pathogen evolution. Many resistance genes evolved long ago in natural environments with no anthropogenic influence but these genes are now rapidly spreading to and among huma...

Boriana K. Tchernookova, Ethan R. Naylor, 4 Robert Paul Malchow 5 6 1 Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL, USA 7 2 Department of Biology, Indiana Wesleyan University, Marion, IN, USA 8 3 National Eye Institute, Bethesda, MD, USA 9 4 Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, 10 Chicago, IL, USA 11 12