In a paper published online in advance in Nature this week, members of the Heliconius Genome Consortium report having sequenced the genome of the neotropical butterfly H. melpomene, which they compared "with other taxa to investigate chromosomal evolution in Lepidoptera and gene flow among multiple Heliconius species and races." Further, using genomic resequencing, the group presents evidence of "hybrid exchange of genes between three co-mimics, H.