Oct 28th, 2013 by The Editors
Auteurs : Randolph M. Nesse et George C. Williams, traduit de l’anglais par Maude Bernardet.
Éditions De Boeck, octobre 2013 ISBN : 978-2804181710
Ouvrage fondateur de la médecine darwinienne, initialement paru en 1994, Pourquoi
tombons-nous malade ? reste le livre de référence de ce champ disciplinaire. George Williams et Randolph Nesse en exposent de manière accessible les principes, mettant en perspective l’histoire évolutive des humains pour comprendre l’émergence des maladies. Les auteurs soulèvent notamment le fait que de nombreux aspects des maladies sont en fait des effets collatéraux du processus évolutif : défenses du corps, compromis coûts-bénéfices dans les fonctions de nos corps, legs historiques, changement de notre environnement plus rapide que le processus évolutif lui-même.
Les sujets abordés sont nombreux, allant du principe de la course aux armes avec les agents infectieux aux implications que la prise en compte du phénomène de l’évolution peut avoir sur la recherche et la pratique de la santé, en élargissant la réflexion sur le vieillissement, les interactions intra-familiales et en considérant d’un abord nouveau les troubles psychiatriques.
L’écriture est illustrée de manière concrète, rendant le livre abordable pour les non scientifiques et son contenu stimulant pour la réflexion des spécialistes. Continue Reading »
Oct 23rd, 2013 by The Editors
By Edward H. Morrow and Tim Connallon. In Evolutionary Applications 4 SEP 2013 DOI: 10.1111/eva.12097 (open access)
Mutation and selection are thought to shape the underlying genetic basis of many common human diseases. However, both processes depend on the context in which they occur, such as environment, genetic background, or sex. Sex has widely known effects on phenotypic expression of genotype, but an analysis of how it influences the evolutionary dynamics of disease-causing variants has not yet been explored. We develop a simple population genetic model of disease susceptibility and evaluate it using a biologically plausible empirically based distribution of fitness effects among contributing mutations. The model predicts that alleles under sex-differential selection, including sexually antagonistic alleles, will disproportionately contribute to genetic variation for disease predisposition, thereby generating substantial sexual dimorphism in the genetic architecture of complex (polygenic) diseases. This is because such alleles evolve into higher population frequencies for a given effect size, relative to alleles experiencing equally strong purifying selection in both sexes. Our results provide a theoretical justification for expecting a sexually dimorphic genetic basis for variation in complex traits such as disease. Moreover, they suggest that such dimorphism is interesting – not merely something to control for – because it reflects the action of natural selection in molding the evolution of common disease phenotypes.
Full article here.
Oct 21st, 2013 by The Editors
By Marlene Zuk and Mark E. Borrello
In Biol. Lett. December 23, 2013 9 6 20130367; doi:10.1098/rsbl.2013.0367 1744-957X
Abstract: W.D. Hamilton was most known for his work on two topics: social evolution and parasites. Although at first glance these seem to be disparate interests, they share many attributes and have logical connections within evolutionary biology. Nevertheless, Hamilton’s contributions in these areas met with very different receptions, with his place in the field of social evolution assured, but his work on the role of parasites perceived as more specialized. We take an historical approach to examine the reasons for this difference.
Oct 21st, 2013 by The Editors
P53 mutation selected for
A Polymorphic p53 Response Element in KIT Ligand Influences Cancer Risk and Has Undergone Natural Selection
By Jorge Zeron-Medina, Xuting Wang, et al.
An accessible overview by Brett Smith is in RedOrbit here
The article provides evidence for positive selection for a mutation in p53, KITLG, that causes testicular cancer. They note that this same allele influences the rate of replication of melanin producing cells in response to UV radiation. This allele is much more common in Caucasians than Africans, and testicular cancer is 4-5 times more common in Caucasian men. Continue Reading »
Oct 13th, 2013 by The Editors
BY HONG CHEN in the Daily Bruin Sept 30, 2013
In the eyes of some scientists, anxiety disorders have evolved from primitive human instincts, and examining their histories is crucial for medicine today.
This is the basis of evolutionary medicine, an emerging field of biology and the subject material of a new minor now offered at UCLA.
Evolutionary medicine looks at modern medicine through an evolutionary and historical perspective, said Daniel Blumstein, chair of the UCLA Department of Ecology and Evolutionary Biology and program director of the evolutionary medicine minor. Read more
Oct 13th, 2013 by The Editors
Genome organisation and the role of centromeres in evolution of the erythroleukaemia cell line HEL
Ruth N. MacKinnon, Meaghan Wall, Adrian Zordan, Srilakshmi Nutalapati, Bruce Mercer, Joanne Peverall, and Lynda J. Campbell
EMPH published 1 October 2013, 10.1093/emph/eot020
Abstract: We describe in detail the abnormal chromosomes of HEL, a human leukaemia
cell line grown in many laboratories. Complementary high resolution and
whole chromosome analysis tools, including the localisation of repetitive
DNA sequences on intact chromosomes, are essential for understanding
genome remodelling and evolution in cancer cells.
How effectively can HIV phylogenies be used to measure heritability?
George Shirreff, Samuel Alizon, Anne Cori, Huldrych F. Günthard, Oliver
Laeyendecker, Ard van Sighem, Daniela Bezemer, and Christophe Fraser
EMPH published 13 September 2013, 10.1093/emph/eot019
Oct 11th, 2013 by The Editors
Sep 28th, 2013 by Neil Greenspan
A central focus of recent research aimed at developing a vaccine for HIV-1 is the identification of potent broadly-neutralizing antibodies (bNAbs). Due to work from several laboratories, many such antibodies have now been identified, produced in quantity as monoclonal antibodies, and characterized with respect to key properties such as epitope specificity, affinity for the corresponding HIV-1 epitope, and neutralizing activity against many strains of varying susceptibility to antibody-mediated inactivation (important examples of these publications are: Scheid et al., 2009; Walker et al., 2009; Wu et al., 2010; Walker et al., 2011; Huang et al., 2012). These successes notwithstanding, the scale of the challenge facing the vaccine developers is clarified by the following facts: 1) potent bNAbs only develop in 10-30% of infected individuals, 2) it typically takes between two and three or four years after initial infection for these antibodies to appear in the blood of these individuals, and 3) antibodies with the desired attributes often have extraordinary numbers of somatic mutations in the variable domains that mediate binding to the HIV-1 antigen (Klein et al., 2013a). A study (Klein et al., 2013b) published earlier this year from the laboratory of Michel Nussenzweig both illuminates one possible factor accounting for the impressive length of time and number of mutations associated with the generation of potent bNAbs and provides an extraordinary example of the power of intense selection to confound expectations arising from previously observed associations. In this instance, the undermined expectations related to the well-established functional correlates of hypervariable and framework regions within antibody variable domains. Continue Reading »
Tags: affinity maturation, amino acid sequence variability, B lymphocytes, broadly neutralizing antibodies, framework regions (FW), germinal centers, HIV-1, hypervariable regions (HV), Principle of Radical Evolutionary Indifference, somatic hypermutation, van der Waals contact, variable domains
Sep 14th, 2013 by The Editors
Robert L. Perlman, Evolution and Medicine
Oxford University Press, 2013. Xiii+162 pp. $98.50 hb.; $49.50 pb. and $29.99 ebook
Book Review by Michael Ruse, September 14, 2013 PDF of this review
Evolution has never been a value-free idea. Ultimately, it has always been all about us. It started in the early Eighteenth Century as an epiphenomenon on the new philosophy of progress. The Ancient Greeks did not really have an idea of historical change and certainly not one of upwards climb. Plato’s Republic, for example, saw rise and development and then decay and decline. People are often surprised that, having built an ideal state, then at the end of the book Plato sets about letting it fade and whither. This was bound to be. For him, this world of ours is one of change and lack of permanence. Nothing lasts, not even the best. At most, history is like a sine curve, up and down endlessly. True stability is to be found only in the rational world, the world of Forms. Continue Reading »
Sep 2nd, 2013 by The Editors
The effect of artificial light on melatonin and circadian rhythms has been uncertain. This small study shows dramatic differences resulting from artificial vs natural light exposure.
Wright, Kenneth†P, McHill, Andrew†W, Birks, Brian†R, Griffin, Brandon†R, Rusterholz, Thomas, & Chinoy, Evan†D. (2013). Entrainment of the Human Circadian Clock to the Natural Light-Dark Cycle. Current biology : CB, 23(16), 1554-1558. Link here, not open access
Summary: The electric light is one of the most important human inventions. Sleep and other daily rhythms in physiology and behavior, however, evolved in the natural light-dark cycle , and electrical lighting is thought to have disrupted these rhythms. Yet how much the age of electrical lighting has altered the human circadian clock is unknown. Here we show Continue Reading »
Aug 24th, 2013 by Neil Greenspan
Currently, I am on vacation near the beach in South Carolina. Consequently, I have opted for a topic that is bit different than the majority of my monthly commentaries in that it focuses not on a recent original report but instead on a conceptual point made in a book over thirty years ago. Nevertheless, after a somewhat less strictly scientific diversion I will come to the central idea at issue, which is arguably the premier exemplar of the relevance of evolutionary principles to the operation of the immune system on short time scales, by which I refer to the concept of clonal selection. But first, we make a foray into the world of magazine publishing and the niche within that domain focusing on the arguably more intellectual readers. Continue Reading »
Tags: acute B lymphocytic leukemia, affinity, antibody, autoimmune disease, B lymphocytes, blood, cancer, clonal selection theory, extended phenotype, immunity, immunoglobulin, lupus, neutrophils, plasma, Richard Dawkins, Sir Frank Macfarlane Burnet, T lymphocytes, world thinkers
Aug 21st, 2013 by The Editors
Funkhouser LJ, Bordenstein SR (2013) Mom Knows Best: The Universality of Maternal Microbial Transmission. PLoS Biol 11(8): e1001631. doi:10.1371/journal.pbio.100163 (Open Access)
The sterile womb paradigm is an enduring premise in biology that human infants are born sterile. Recent studies suggest that infants incorporate an initial microbiome before birth and receive copious supplementation of maternal microbes through birth and breastfeeding. Moreover, evidence for microbial maternal transmission is increasingly widespread across animals. This collective knowledge compels a paradigm shift—one in which maternal transmission of microbes advances from a taxonomically specialized phenomenon to a universal one in animals. It also engenders fresh views on the assembly of the microbiome, its role in animal evolution, and applications to human health and disease.
Aug 10th, 2013 by The Editors
Champion MD, Gray V, Eberhard C, Kumar S (2013) The Evolutionary History of Amino Acid Variations Mediating Increased Resistance of S.aureus Identifies Reversion Mutations in Metabolic Regulators.
PLoS ONE 8(2): e56466. doi:10.1371/journal.pone.0056466 (open access)
Reversion to ancestral alleles
The evolution of resistance in Staphylococcus aureus occurs rapidly, and in response to all known antimicrobial treatments. Numerous studies of model species describe compensatory roles of mutations in mediating competitive fitness, and there is growing evidence that these mutation types also drive adaptation of S. aureus strains. However, few studies have tracked amino acid changes during the complete evolutionary trajectory of antibiotic adaptation or been able to predict their functional relevance. Here, we have assessed the efficacy of computational methods to predict biological resistance of a collection of clinically known Resistance Associated Mutations (RAMs). We have found that >90% of known RAMs are incorrectly predicted to be functionally neutral by at least one of the prediction methods used. Continue Reading »
Jul 30th, 2013 by Neil Greenspan
In lay publications, it is commonplace for writers to refer to the deoxynucleotide sequence of an individual’s nuclear genome as that individual’s “code” and to the determination of that sequence as “deciphering the code.” Molecular biologists mean by the “genetic code,” not a DNA sequence but the relationships between RNA (or DNA) nucleotide triplets and particular amino acids. For those interested in clinical genetics, the real code-deciphering challenge is much more daunting than determining nucleotide sequences; it is the mapping of genotypes to medically-relevant phenotypes, i.e. predicting diseases from the totality of sequences in a genome.
The somewhat cryptic paradox at the heart of genome-based personalized medicine at the present state of our understanding is easily put: Continue Reading »
Tags: 1000 Genomes Project, algorithms, disease risk, evolution, genetic code, genetic variants, genotype, incidentalome, minor allele frequency, mutations, pathogenicity, personalized medicine, phenotype, structure-function correlation, the Human Gene Mutation Database (HGMD), whole exome sequencing (WES), whole-genome sequencing (WGS)
Jul 24th, 2013 by The Editors
By Mazzon, M., Peters, N. E., Loenarz, C., Krysztofinska, E. M., Ember, S. W. J., Ferguson, B. J., & Smith, G. L. (2013).
In: Proceedings of the National Academy of Sciences, 110(30), 12444-12449. doi: 10.1073/pnas.1302140110 open access
Abstract: Viruses have evolved sophisticated strategies to exploit host cell function for their benefit. Here we show that under physiologically normal oxygen levels (normoxia) vaccinia virus (VACV) infection leads to a rapid stabilization of hypoxia-inducible factor (HIF)-1α, Continue Reading »
Jul 23rd, 2013 by The Editors
These videos are from “Evolutionary Foundations for Medicine and Public Health: Focus on Infection and Cancer,” a course organized by Randolph Nesse that was offered from August 6-10, 2012 at the Mount Desert Island Biological Laboratory, Bar Harbor, Maine. Sponsors who made the course possible include the National Evolutionary Synthesis Center, The Dana Farber Cancer Institute, and The Evolution, Medicine, and Public Health Foundation. Editing of these videos was made possible Joon Yun, MD and the Palo Alto Institute. Editing of more videos from the course is underway; when they are available, links will be posted at The Evolution & Medicine Review.
Jul 8th, 2013 by The Editors
Robert Perlman’s new book Evolution and Medicine has just been released in hardcover, softcover, and Kindle editions, in time for Fall Term courses. Book description below, a full review will appear on the EMR later this month. OUP link here Amazon link here
Book Description: Evolution and Medicine provides an accessible introduction to the new field of evolutionary medicine. Evolutionary concepts help explain why we remain vulnerable to disease, how pathogens and cancer cells evolve, and how the diseases that affected our evolutionary ancestors have shaped our biology. Evolution and Medicine interweaves the presentation of evolutionary principles with examples that illustrate how an evolutionary perspective enhances our understanding of disease. The book discusses the theory of evolution by natural selection, the genetic basis of evolutionary change, Continue Reading »
Jul 7th, 2013 by The Editors
Ojala, V., Laitalainen, J. and Jalasvuori, M. (2013), Fight evolution with evolution: plasmid-dependent phages with a wide host range prevent the spread of antibiotic resistance. Evolutionary Applications. doi: 10.1111/eva.12076 (open access)
Abstract: The emergence of pathogenic bacteria resistant to multiple antibiotics is a serious worldwide public health concern. Whenever antibiotics are applied, the genes encoding for antibiotic resistance are selected for within bacterial populations. This has led to the prevalence of conjugative plasmids that carry resistance genes and can transfer themselves between diverse bacterial groups. In this study, we investigated whether it is feasible to attempt to prevent the spread of antibiotic resistances with a lytic bacteriophage, Continue Reading »
Jul 4th, 2013 by The Editors
Cholera is altering the human genome, a news article in Science by Mitch Leslie, offers an open access summary of a technical paper that just appeared in Science Translational Medicine:. The news article begins:
Cholera kills thousands of people a year, but a new study suggests that the human body is fighting back. Researchers have found evidence that the genomes of people in Bangladesh—where the disease is prevalent—have developed ways to combat the disease, a dramatic case of human evolution happening in modern times. (full version here)
The technical article is unfortunately not open access.
Karlsson, Elinor K., Harris, Jason B., Tabrizi, Shervin, Rahman, Atiqur, Shlyakhter, Ilya, Patterson, Nick, . . . LaRocque, Regina C. (2013). Natural Selection in a Bangladeshi Population from the Cholera-Endemic Ganges River Delta. Science Translational Medicine, 5(192), 192ra186. doi: 10.1126/scitranslmed.3006338 (not open access)
Abstract: As an ancient disease with high fatality, cholera has likely exerted strong selective pressure on affected human populations. We performed a genome-wide study of natural selection in a population from the Ganges River Delta, the historic geographic epicenter of cholera. We identified 305 candidate selected regions Continue Reading »
Jun 28th, 2013 by Neil Greenspan
The term “genetic code” is associated with a measure of ambiguity. For molecular biologists, “genetic code” has historically referred to a table that provides for each messenger RNA ribonucleotide triplet the corresponding amino acid that is incorporated into the growing end of a nascent polypeptide chain, i.e. the translation from RNA sequence to protein sequence. In colloquial parlance, “genetic code” is frequently used to refer to all or part of the deoxribonucleotide sequence of a genome. A recent paper, published online ahead of print in Proceedings of the National Academy of Sciences (Bezerra et al., PNAS, 2013) demonstrates that this semantic ambiguity can have a counterpart in the ribosomal interpretation of the genetic code, using the technical molecular biological meaning of the latter term. Continue Reading »
Tags: amino acid incorporation, Candida albicans, caspofungin, colony morphology, cytokines, drug tolerance, fluconazole, genetic code, growth, IL-10, IL-17A, inflammation, itraconazole, leucine, pathogen, polypeptide chain, proteome, ribosome, serine, stomach pathology, TNF-alpha, transfer RNA (tRNA), translation, virulence