Irish potato famine sparked 180-year evolutionary arms race

The Irish potato famine of 1845–52 resulted in more than a million deaths. Another million people were displaced, and Ireland’s population was reduced by about 25%. The cause of widespread potato rot that devastated the staple crop was a fungus-like microbe, an oomycete called Phytophthora infestans , more commonly known as potato blight. Since then, breeders have worked tirelessly to develop newer varieties of potato that are resistant to blight. Now, new research has shed light on the 180-year-long evolutionary arms race between potatoes and their pathogen ( Nat. Comm. 2024, DOI: 10.1038/s41467 -024-50749-4 ). Jean Ristaino , a plant pathologist at North Carolina State University who led the research group, acknowledges that many factors aside from potato blight made Ireland uniquely susceptible to famine. They include “an overreliance on subsistence of a single food crop, absentee landlords, and slow food relief policies by the British.” Yet the role of