Curli are proteins made by E. coli, first identified in strains that cause bovine mastitis. Curli are part of the protein matrix that allows bacteria to attach to host cells, a trait that allows them to colonize and invade host tissues. One interesting notable factoid: curli are amyloid fibers. Bacterial […]
After a couple of decades in practice in emergency medicine, I often coach trainees to think about how to weigh the benefits and costs of every diagnostic and therapeutic procedure. I tell them that they should only order medications and interventions that are needed for a given patient. I also […]
Three learning objectives will be the focus of 2023’s evolutionary medicine elective. Priority 1. We will discuss “tree thinking” and learn the evolutionary principle of common descent. Our shared evolutionary legacy is the basis for the One Health movement that seeks to bridge the gap between human and veterinary medicine […]
The two main evolutionary concepts I teach students about aging are George C. Williams’ idea of antagonistic pleiotropy and the declining power of selection hypothesis (aka selection shadow hypothesis) proposed by J.S. Haldane and Peter Medawar in the 1940s and 1950s. Medawar posited that beneficial genes, coding for body maintenance […]
In 2014, Carlo Maley, Athena Aktipis, and I wrote an article on eating behavior and the gut microbiota that was published in Bioessays. We proposed that unhealthy food preferences, cravings and aversions may serve the evolutionary interests of microbes in our guts, sometimes in conflict with our own interests. We suggested […]
The New Year is here, and the pale sun may only make a brief appearance, if at all. We normally get vitamin D from the sun, with a lesser contribution from diet, so you may ask yourself – should I be taking vitamin D? In our culture, we are exhorted […]
Eerie! Watch the NASA animation of the space probe Dawn approaching the dwarf planet Ceres. Eyes, right! When I saw this it reminded me of a moment hiking down a red rock canyon in Utah. I looked up and suddenly saw this: When I saw the pictograph, and when I […]
This is a re-post of a previous entry, now updated. Life history theory, a concept first described by Yale evolutionary biologist Stephen Stearns, is the application of evolutionary biology to the entire life cycle from birth to death. It includes the hypothesis that features of life are shaped by natural […]
Disease is a ubiquitous feature of life on earth. All biological life on the plant evolved. Diseases evolved too. Problem is, diseases are fitness reducing for their hosts. By that definition, diseases are maladaptive. Yet the motor of evolution, natural selection, favors traits that are adaptive, not maladaptive. Why then, […]
Multi-cellular organisms have solved a special problem that single celled organisms lack: how to make cells cooperate together and restrain themselves from reproduction. In single cell organisms, there is no, or little, cost to replication. Every division and replication results in higher fitness. Not so for multi cell organisms. Multi-cell organisms […]
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