Assessing maize genetic erosion

Dyer et al. (1) report a rapid decline in maize varieties grown by Mexican farmers, arguing that their results are in contrast with previously reported work. We believe that the support for this rapid decline is weak, and that the contrast with previously reported work is false. Dyer et al. (1) set up a straw man: they show that average household maize diversity reported in case studies has increased over time and then argue that their own finding is flawed because of the nonrepresentative nature of these studies. Indeed, these studies were not designed for that, and any …