Evolution and medicine: the long reach of "Dr. Darwin"

In this review we consider the new science of Darwinian medicine. While it has often been said that evolutionary theory is the glue that holds the disparate branches of biological inquiry together and gives them direction and purpose, the links to biomedical inquiry have only recently been articulated in a coherent manner. Our aim in this review is to make clear first of all, how evolutionary theory is relevant to medicine; and secondly, how the biomedical sciences have enriched our understanding of evolutionary processes. We will conclude our review with some observations of the philosophical significance of this interplay between evolutionary theory and the biomedical sciences

Evolution and Medicine: The Long Reach of Dr. Darwin

In this review we consider the new science of Darwinian medicine. While it has often been said that evolutionary theory is the glue that holds the disparate branches of biological inquiry together and gives them direction and purpose, the links to biomedical inquiry have only recently been articulated in a coherent manner. Our aim in this review is to make clear first of all, how evolutionary theory is relevant to medicine; and secondly, how the biomedical sciences have enriched our understanding of evolutionary processes. We will conclude our review with some observations of the philosophical significance of this interplay between evolutionary theory and the biomedical sciences

Comparative genomics of Escherichia coli isolated from patients with inflammatory bowel disease

<p>Abstract</p> <p>Background</p> <p>Inflammatory bowel disease (IBD) is used to describe a state of idiopathic, chronic inflammation of the gastrointestinal tract. The two main phenotypes of IBD are Crohn's disease (CD) and ulcerative colitis (UC). The major cause of IBD-associated mortality is colorectal cancer. Although both host-genetic and exogenous factors have been found to be involved, the aetiology of IBD is still not well understood. In this study we characterized thirteen <it>Escherichia coli </it>strains from patients with IBD by comparative genomic hybridization employing a microarray based on 31 sequenced <it>E. coli </it>genomes from a wide range of commensal and pathogenic isolates.</p> <p>Results</p> <p>The IBD isolates, obtained from patients with UC and CD, displayed remarkably heterogeneous genomic profiles with little or no evidence of group-specific determinants. No IBD-specific genes were evident when compared with the prototypic CD isolate, LF82, suggesting that the IBD-inducing effect of the strains is multifactorial. Several of the IBD isolates carried a number of extraintestinal pathogenic <it>E. coli </it>(ExPEC)-related virulence determinants such as the <it>pap</it>, <it>sfa</it>, <it>cdt </it>and <it>hly </it>genes. The isolates were also found to carry genes of ExPEC-associated genomic islands.</p> <p>Conclusions</p> <p>Combined, these data suggest that <it>E. coli </it>isolates obtained from UC and CD patients represents a heterogeneous population of strains, with genomic profiles that are indistinguishable to those of ExPEC isolates. Our findings indicate that IBD-induction from <it>E. coli </it>strains is multifactorial and that a range of gene products may be involved in triggering the disease.</p

Modulation of Prey‐capture Behavior in Plethodon Cinereus (Green) (Amphibia: Caudata)

Many feeding kinematic studies do not identify sources of mechanical variation related to the type or size of prey. Studies of salamanders have concentrated on determining the morphological basis of feeding mechanics or on phylogenetic comparisons; few have examined variability within a species. A series of feeding trials was designed to test whether Plethodon cinereus of different age/size classes exhibits stereotypic patterns in capturing prey of differing type and size. Stopframe video analyses of feedings were made using 19 salamanders of varying body size and four prey types chosen to resemble items in the natural diet of the species. Five morphological features of each salamander, length and width of prey items, and 15 kinematic variables were used to describe each feeding trial. Statistical analyses of kinematic and morphological variables show that the feeding behavior of this species varies significantly with prey type. Effects of salamander size and prey size within prey types were a source of variation in some kinematic variables; among‐individual variation partitioned with salamander body size. Different feeding modes resulted from distinctive combinations of distances from prey, amount of tongue protrusion, body movements, and duration of mouth closure, which varied with the use of jaw prehension and lingual prey capture. Presence of a repertoire of behaviors, composed of versatile combinations of movements, suggests that Plethodon cinereus modulates feeding mechanics to capture different types of prey. Consideration of natural prey in experiments, and of prey type in comparisons made across taxa, are necessary to investigations of the evolution of feeding behaviors