International Journal of Evolutionary Biology

[This corrects the article DOI: 10.1155/2013/926702.].

Adaptive radiation in bacteria has been investigated using Wrinkly Spreaders (WS), a morphotype which colonises the air-liquid (A-L) interface of static microcosms by biofilm formation with a significant fitness advantage over competitors growing lower down in the O2-limited liquid column. Here, we investigate several environmental parameters which impact the ecological opportunity that the Wrinkly Spreaders exploit in this model system. Manipulation of surface area/volume ratios suggests that the size of the WS niche was not as important as the ability to dominate the A-L interface and restrict competitor growth...

The lions of North Africa were unique in ecological terms as well as from a human cultural perspective and were the definitive lions of Roman and Medieval Europe. Labelled "Barbary" lions, they were once numerous in North Africa but were exterminated by the mid-20th century. Despite subsequent degeneration of the Atlas Mountain ecosystem through human pressures, the feasibility of lion reintroduction has been debated since the 1970s. Research on the long-established captive lion collection traditionally kept by the sultans and kings of Morocco has enabled selective breeding coordinated across Moroccan and European zoos involving a significant number of animals...

Since the rise of photosynthesis, life has influenced terrestrial atmosphere, particularly the O2 and the CO2 content (the latter being originally more than 95%), changing the chemistry of waters, atmosphere, and soils. Billions of years after, a far offspring of these first unicellular forms conquered emerging lands, not only completely changing landscape, but also modifying geological cycles of deposition and erosion, many chemical and physical characteristics of soils and fresh waters, and, more, the cycle of various elements...

When cardiovascular diseases are viewed from an evolutionary biology perspective, a heightened thrifty and an inflammatory design could be their mechanisms. Human ancestors confronted a greater infectious load and were subjected to the selection for proinflammatory genes and a strong inflammatory function. Ancestors also faced starvation periods that pressed for a thrifty genotype which caused fat accumulation. The pressure of sustaining gluconeogenesis during periods of poor nourishment selected individuals with insulin resistance...

Males have evolved a variety of behavioral, morphological, and physiological traits to manipulate their mates in order to maximize their chances of success. These traits are bound to influence how females respond to male behaviors and influence the nature of sexual selection/conflict. A common consequence of aggressive male mating strategies in Drosophila melanogaster is the reduction of female lifespan. Our study shows that this is common across members of the simulans clade. Reduced life expectancy of females implies that female contribution to a population is less than that of males per generation...

Understanding the mechanisms that drive acid-base regulation in organisms is important, especially for organisms in aquatic habitats that experience rapidly fluctuating pH conditions. Previous studies have shown that carbonic anhydrases (CAs), a family of zinc metalloenzymes, are responsible for acid-base regulation in many organisms. Through the use of phylogenetic tools, this present study attempts to elucidate the evolutionary history of the α-CA superfamily, with particular interest in the emerging model aquatic organism Daphnia pulex...

Azospirillum brasilense is a nitrogen-fixing bacterium living in association with plant roots. The genome of the strain Sp245, isolated in Brazil from wheat roots, consists of one chromosome and six plasmids. In this work, the A. brasilense Sp245 plasmids were analyzed in order to shed some light on the evolutionary pathways they followed over time. To this purpose, a similarity network approach was applied in order to identify the evolutionary relationships among all the A. brasilense plasmids encoded proteins; in this context a computational pipeline specifically devoted to the analysis and the visualization of the network-like evolutionary relationships among different plasmids molecules was developed...

Sex chromosomes bearing the sex-determining gene initiate development along the male or female pathway, no matter which sex is determined by XY male or ZW female heterogamety. Sex chromosomes originate from ancient autosomes but evolved rapidly after the acquisition of sex-determining factors which are highly divergent between species. In the heterogametic male system (XY system), the X chromosome is relatively evolutionary silent and maintains most of its ancestral genes, in contrast to its Y counterpart that has evolved rapidly and degenerated...

Baldwin's synthesis of the Organicist position, first published in 1896 and elaborated in 1902, sought to rescue environmentally induced phenotypes from disrepute by showing their Darwinian significance. Of particular interest to Baldwin was plasticity's mediating role during environmental change or colonization-plastic individuals were more likely to successfully survive and reproduce in new environments than were nonplastic individuals. Once a population of plastic individuals had become established, plasticity could further mediate the future course of evolution...

A high diversity of mating calls is found among frogs. The calls of most species, however, are simple, in comparison to those of mammals and birds. In order to determine if the mechanics of the larynx could explain the simplicity of treefrog calls, the larynges of euthanized males were activated with airflow. Laryngeal airflow, sound frequency, and sound intensity showed a positive direct relationship with the driving air pressure. While the natural calls of the studied species exhibit minimal frequency modulation, their larynges produced about an octave of frequency modulation in response to varying pulmonary pressure...

External genitalia are one of the most rapidly evolving morphological features in insects. In the Drosophila melanogaster species subgroup, males possess a nonfertilizing external genital structure, called the posterior lobe, which is highly divergent among even closely related species. A previous study on this subgroup mapped two genomic regions that affect lobe size and four that affect lobe shape differences between D. mauritiana and D. sechellia; none of the regions affected both size and shape. Here, we investigate whether three of these significant regions also affect lobe size and shape differences between the overlapping species pair D...

Sub-Saharan Africa has continued leading in prevalence and incidence of major infectious disease killers such as HIV/AIDS, tuberculosis, and malaria. Epidemiological triad of infectious diseases includes susceptible host, pathogen, and environment. It is imperative that all aspects of vertices of the infectious disease triad are analysed to better understand why this is so. Studies done to address this intriguing reality though have mainly addressed pathogen and environmental components of the triad. Africa is the most genetically diverse region of the world as well as being the origin of modern humans...

The problems of the origin and evolution of meiosis include the enigmatic variability of the synaptonemal complexes (SCs) which, being morphology similar, consist of different proteins in different eukaryotic phyla. Using bioinformatics methods, we monitored all available eukaryotic proteomes to find proteins similar to known SC proteins of model organisms. We found proteins similar to SC lateral element (LE) proteins and possessing the HORMA domain in the majority of the eukaryotic taxa and assume them the most ancient among all SC proteins...

Mycobacterium tuberculosis (Mtb) is a pathogenic bacteria species in the genus Mycobacterium and the causative agent of most cases of tuberculosis. Tuberculosis (TB) is the leading cause of death in the world from a bacterial infectious disease. This antibiotic resistance strain lead to development of the new antibiotics or drug molecules which can kill or suppress the growth of Mycobacterium tuberculosis. We have performed an in silico comparative analysis of metabolic pathways of the host Homo sapiens and the pathogen Mycobacterium tuberculosis (H37Rv)...

Eukaryotic RNA polymerase III transcribes tRNA genes, and this requires the transcription factor TFIIIC. Promoters are within genes, with which the B-block binding subunit of TFIIIC associates to initiate transcription. The binding subunits are more than 1000 amino acids in length in various eukaryotic species. There are four regions with conserved sequence similarities in the subunits. The helix-turn-helix motif is included in one of these regions and has been characterized as the B-block_TFIIIC family in the Pfam database...

Experimental evolution studies have investigated adaptive radiation in static liquid microcosms using the environmental bacterium Pseudomonas fluorescens SBW25. In evolving populations a novel adaptive mutant known as the Wrinkly Spreader arises within days having significant fitness advantage over the ancestral strain. A molecular investigation of the Wrinkly Spreader has provided a mechanistic explanation linking mutation with fitness improvement through the production of a cellulose-based biofilm at the air-liquid interface...

DNA methylation is a key epigenetic modification in the vertebrate genomes known to be involved in biological processes such as regulation of gene expression, DNA structure and control of transposable elements. Despite increasing knowledge about DNA methylation, we still lack a complete understanding of its specific functions and correlation with environment and gene expression in diverse organisms. To understand how global DNA methylation levels changed under environmental influence during vertebrate evolution, we analyzed its distribution pattern along the whole genome in mammals, reptiles and fishes showing that it is correlated with temperature, independently on phylogenetic inheritance...

The vast diversity of floral colours in many flowering plant families, paired with the observation of preferences among pollinators, suggests that floral colour may be involved in the process of speciation in flowering plants. While transitions in floral colour have been examined in numerous genera, we have very little information on the consequences of floral colour transitions to the evolutionary success of a clade. Overlaid upon these patterns is the possibility that certain floral colours are more prevalent in certain environments, with the causes of differential diversification being more directly determined by geographical distribution...

Recently published craniometric and genetic studies indicate a predominantly indigenous ancestry of Indian populations. We address this issue with a fuller coverage of Indian craniometrics than any done before. We analyse metrical variability within Indian series, Indians' sexual dimorphism, differences between northern and southern Indians, index-based differences of Indian males from other series, and Indians' multivariate affinities. The relationship between a variable's magnitude and its variability is log-linear...