… bridging the gap
Jan 24th, 2012 by Neil Greenspan
As noted in my last post, the selective advantage of heterozygosity for the sickle allele at the beta-globin locus has been known since Allison’s report in 1954 (Lancet). Nevertheless, a plausible and detailed mechanism to account for the protective effect of an allele that is typically highly deleterious when homozygous has not been forthcoming until now. Continue Reading »
Jan 22nd, 2012 by The Editors
Abstract
Cancers evolve by a reiterative process of clonal expansion, Continue Reading »
Jan 21st, 2012 by The Editors
A central problem in population genetics is to detect and analyze positive natural selection by which beneficial mutations are driven to fixation. The hitchhiking effect of a rapidly spreading beneficial mutation, which results in local removal of standing genetic variation, allows such an analysis using DNA sequence polymorphism. However, Continue Reading »
Jan 17th, 2012 by The Editors
Evolution: Education and Outreach. Volume 4 Number 4 (Dec 2011)
Guest Editors: Kristin Jenkins and Michael F Antolin
Editorial by Niles Eldredge and Gregory Eldredge
Evolution and Medicine by Kristin P. Jenkins and Michael F. Antolin Continue Reading »
Jan 5th, 2012 by The Editors
Reference: Pierre M. Durand and Theresa L. Coetzer (2011). Evolutionary Biology and Drug Development, Drug Discovery and Development – Present and Future, Izet M. Kapetanovic (Ed.), ISBN: 978-953-307-615-7, InTech
Dec 28th, 2011 by Neil Greenspan
There is probably no more canonical example of the relevance of evolutionary genetics to clinical medicine than sickle cell disease. The relevance of the sickle allele, in heterozygous form, at the beta-globin locus for resistance to falciparum malaria was published by Allison in 1954 (Lancet), and the precise amino acid substitution responsible for the phenotype of sickle cell disease, when the mutation is present in homozygous form, was identified by Ingram in 1956 (Nature). Two recent papers Continue Reading »
Dec 21st, 2011 by The Editors
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Why Has Natural Selection Left Us So Vulnerable to Anxiety and Mood Disorders? Randolph M Nesse Anxiety: An Evolutionary Approach Melissa Bateson, Ben Brilot, Daniel Nettle Evolutionary Theories of Depression: A Critical Review |
Dec 21st, 2011 by The Editors
In the preface to his 1794 treatise Zoonomia—perhaps the first book in English to present concepts from which modern evolutionary thought eventually arose—Erasmus Darwin, scientist and grandfather of Charles Darwin, wrote that the purpose of such studies is to elucidate the origins of disease. Yet evolutionary biology has had little explicit role in the training of health professionals1 and thus in how medicine is practised and research questions are developed. Continue Reading »
Dec 20th, 2011 by The Editors
Evo Edu Outreach DOI 10.1007/s12052-011-0374-x
Abstract Most early evolutionary thinkers came from medicine, yet evolution has had a checkered history in medical education. It is only in the last few decades that serious efforts have begun to be made to integrate evolutionary biology into the medical curriculum. However, it is not clear when, where (independently or as part of preclinical or clinical teaching courses) and, most importantly, how should medical students learn the basic principles of evolutionary biology applied to medicine, known today as evolutionary or Darwinian medicine. Most clinicians are ill-prepared to teach evolutionary biology Continue Reading »
Dec 20th, 2011 by The Editors
Journal of Evolutionary Biology DOI: 10.1111/j.1420-9101.2011.02437.x
Bacteria secrete a large variety of beneficial metabolites into the environment, which can be shared as public goods among producing bacteria, but also be exploited by nonproducing cheats. Here, we focus on cooperative production of iron-chelating molecules (siderophores) in the bacterium Pseudomonas aeruginosa to study how relevant ecological factors influence selection for cheating. We designed patch-structured metapopulations that allowed us introducing among-patch ecological variation. We found that cheating readily evolved in uniform iron-limited environments. Continue Reading »
Dec 15th, 2011 by The Editors
Science 16 December 2011: Vol. 334 no. 6062 pp. 1486-1487 DOI: 10.1126/science.334.6062.1486
Ever since Darwin, physicians have wondered why humans haven’t evolved to be healthier. Blame natural selection itself, says Randolph Nesse, a psychiatrist at the University of Michigan, Ann Arbor. Twenty years ago, Nesse and evolutionary biologist George Williams attributed our vulnerability to disease to our evolutionary history. The most widely propagated versions of genes are those that made more babies possible, irrespective of their effect on health and well-being, they noted. Evolution, in other words, didn’t always favor prolonged good health. Viewed through an evolutionary lens, disease symptoms such as fever and diarrhea were likely imperfect weapons in the body’s defenses against infection, they argued. They also pointed out that our immune systems could not evolve fast enough to keep ahead of germs, and that other mismatches have developed between our bodies and modern environments.In their 1991 paper in The Quarterly Review of Biology, Williams and Nesse urged medicine to embrace evolutionary thinking. Aptly titled “The Dawn of Darwinian Medicine,” it called the dearth of evolutionary biology in medical schools “unfortunate” and asked physicians to be “as attuned to Darwin as they have been to Pasteur,” as that would be the only way to truly understand why we get sick and could lead to changes in medical practice. Continue Reading »
Dec 15th, 2011 by The Editors
PLoS Genet 2011, 7:e1001375 (open access)
Abstract
Humans inhabit a remarkably diverse range of environments, and adaptation through natural selection has likely played a central role in the capacity to survive and thrive in extreme climates. Unlike numerous studies that used only population genetic data to search for evidence of selection, here we scan the human genome for selection signals by identifying the SNPs with the strongest correlations between allele frequencies and climate across 61 worldwide populations. We find a striking enrichment of genic and nonsynonymous SNPs relative to non-genic SNPs among those that are strongly correlated with these climate variables. Continue Reading »
Dec 13th, 2011 by The Editors
George Williams defined an evolutionary unit as hereditary information for which the selection bias between competing units dominates the informational decay caused by imperfect transmission. In this article, I extend Williams’ approach to show that the ratio of selection bias to transmission bias provides a unifying framework for diverse biological problems. Specific examples include Haldane and Lande’s mutation–selection balance, Eigen’s error threshold and quasispecies, Van Valen’s clade selection, Price’s multilevel formulation of group selection, Continue Reading »
Dec 10th, 2011 by The Editors
There is increasing urgency to develop effective prevention and treatment for Alzheimer’s disease (AD) as the aging population swells. Yet, our understanding remains limited for the elemental pathophysiological mechanisms of AD dementia that may be causal, compensatory, or epiphenomenal. To this end, we consider AD and why it exists from the perspectives of natural selection, adaptation, genetic drift, and other evolutionary forces. Continue Reading »
Dec 6th, 2011 by The Editors
Journal of the American Orthodontic Society Nov/Dec 2011, p 34-39. Continue Reading »
Dec 6th, 2011 by The Editors
It was organized by Grazyna Jasienska, and sponsored by the Polish Academy of Sciences, Committee of Evolutionary and Theoretical Biology and Institute of Environmental Sciences at Jagiellonian University. Continue Reading »
Dec 1st, 2011 by The Editors
The group, chaired by Mark Schwartz (NYU, Internal Medicine) and Peter Ellison (Harvard, Anthropology), will meet during the next two years. A separate Advisory Group, with distinguished medical leaders, will guide the project. See below for a list of all participants.
Project Summary
Evolutionary biology is a foundational and integrative science for medicine, but few physicians or medical researchers are familiar with its most relevant principles. Continue Reading »
Nov 30th, 2011 by Neil Greenspan
As biomedical technology advances, the probability increases that evolution guided, constrained, or facilitated by scientists will be relevant to medicine. Of particular interest in this context is the increasing ability of investigators to engineer microbes to produce gene products of benefit to individuals in need of specific treatments or for the general maintenance of health. Applications of a more industrial nature are also readily conceivable.
There are different possible paths to the eventual goal of tailored microbial genomes. One approach is the de novo synthesis of whole bacterial genomes followed by transplantation into selected cells previously rendered genome-free (Gibson et al. Science, 2010). I have previously expressed doubt that this scheme is necessarily the most likely means to achieve the goal of engineering bacteria to express gene products and functions of our choosing (Greenspan, 2010). The alternative approaches I had in mind were based on the reasonable supposition that it would ultimately be easier and more efficient for most researchers to employ enhanced versions of already well-developed technologies based on mutation and selection of existing microbial strains.
Church and colleagues (Isaacs et al. Science, 2011) have now obliged by demonstrating the potential for advances in microbial genome engineering based on enhancements in current methods applied to existing bacterial strains and their genomes. More specifically, Isaacs et al. developed new strategies for introducing multiple mutations into the genomes of E. coli cells. Continue Reading »
Nov 22nd, 2011 by The Editors
See this link for a list of articles in the series.
Nov 20th, 2011 by The Editors
Circulation 2009, 119:459-467 (open access)
Susceptibility to common diseases such as coronary heart disease (CHD) may in part reflect historical or evolutionary legacies,3,4 and interest in studying evolutionary biology to gain novel insights into human health and disease is increasing. The evolutionary history of the human species may provide valuable insights into the origin of common diseases beyond what is possible by investigating only the most immediate or “proximal” causes of disease. The potential role of evolutionary biology in explaining disease causation was highlighted by Williams and Nesse3 and is often referred to as Darwinian medicine. Although the relevance of an evolutionary perspective may vary depending on the disease under study, a strong argument could be made for studying the evolutionary genetics of CHD, a leading cause of human morbidity and death.
Unless otherwise noted, original content on the Evolution & Medicine Review is licensed under a Creative Commons Attribution 3.0 Licence.
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