The assembly and reassembly of the genomes of several cotton varieties is reported in Nature Genetics this week, offering insights into the crop plant's evolution and potential avenues for its improvement. A team led by scientists from Wuhan University assembled the genome of the allotetraploid Upland cotton Gossypium herbaceum, which dominates the world's cotton commerce, and improved existing Gossypium arboretum and Gossypium hirsutum genome assemblies.