Review & comment

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  Evolutionary capacitance and evolvability

  Joanna Masel

  Joanna Masel explains how evolvability may be conferred by molecular "switches" that can expose cryptic mutations and allow selection to act on them, with the potential for adaptive changes in phenotype.

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  Natural genetic variation, proteostasis and aging

  Matt Kaeberlein

  Commenting on a study showing that genetic variation in wild strains of C. elegans modifies polyglutamine disease, Matt Kaeberlein explains why this nematode worm has proved a useful model for studying age-associated failures of protein homeostasis, and why the new research holds therapeutic promise.

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  The mathematics of HIV infection

  Alan Perelson, Ruy Ribeiro

  Alan Perelson and Ruy Ribeiro explain how differential equations that model the dynamics of HIV replication in its human host have led to important quantitative insights into the biology of HIV infection.

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  Big science, zombie projects, and what is really inside the cell

  Gregory Petsko

  Gregory Petsko, writing for the BMC Biology tenth birthday Open questions series, argues, with his usual forthrightness, that we need to pay more attention to where the balance of ‘big’ and ‘little’ science is going, and remember how little we know about the interior of the cell.