Nietzsche Undone: An Infection that Doesn’t Kill You Can Make You Weaker

The German philosopher, Friedrich Nietzsche, is known for a number of ideas among which a particularly oft-quoted one is, “That which does not kill us makes us stronger” (https://www.goodreads.com/quotes/30-that-which-does-not-kill-us-makes-us-stronger). A recent report in Cell (Fonseca et al., 2015) offers evidence that in the context of infection and immunity, the above aphorism may not be a reliable guide to reality. (more…)

Phenotypic noise and the evolution of virulence

Commentary on: M. Ackermann, B. Stecher, N. E. Freed, P. Songhet, W.-D. Hardt, and M. Doebeli (2008) Self-destructive cooperation mediated by phenotype noise. Nature 454:987-9

One of the most exciting developments in microbial population biology over the past few years is the recognition that high levels of phenotypic noise – in which genetically identical microbes express different genes and manifest different phenotypes despite a common environment – is widespread in bacterial populations and that this noise plays an important role in bacterial evolutionary ecology (e.g. Elowitz et al. 2002, Balaban et al. 2004, Rosenfeld et al. 2005, Acar et al. 2008, Veening et al. 2008). I have always thought that the best explanations for this phenomenon involve bet hedging in uncertain environments (Seger and Brockmann 1987), and indeed this bet-hedging perspective has been well supported by mathematical modeling (e.g. Thattai and van Oudenaarden 2004, Kussell et al. 2005).

But in this week’s issue of Nature, Martin Ackermann and colleagues propose an alternative explanation (more…)

A Key to the Doors of Perception

Autism is traditionally considered as a severe disorder involving some combination of repetitive behavior and restricted interests, deficits in social reciprocity and language, and mental retardation. But there is a long tradition of counterpoint to such disabilities, in so-called savant skills in fields that range from mathematical calculation and memory to art and music (Heaton and Wallace 2004). In each case, autistic savant skills represent rare yet astounding enhancements of human ability, beyond imagining for most of us. Understanding the cognitive and neurodevelopmental bases of such skills holds the promise of better understanding the causes of autism and enhancing human mental abilities to beyond the norm, if not at least helping us remember where we left the keys. (more…)