SOME diseases march from victim to victim, others fly on the wind – but predicting how fast is tricky.
Christopher Mundt of Oregon State University at Corvallis released a wind-borne wheat fungus in a field and found that the further it spread, the faster the infection front advanced (The American Naturalist, DOI: 10.1086/597220). The acceleration fits a simple equation called a power law, which Mundt found also characterised the Irish potato blight of 1845 and the US corn blight of 1970. West Nile virus and H5N1 bird flu have shown similar spread.
The power law applies to diseases spread via…
