We used 20 de novo genome assemblies to probe the speciation history and architecture of
gene flow in rapidly radiating Heliconius butterflies. Our tests to distinguish incomplete …

Alleles that introgress between species can influence the evolutionary and ecological fate of
species exposed to novel environments. Hybrid offspring of different species are often unfit, …

The Piwi-interacting RNA (piRNA) pathway defends the germline of animals from the deleterious
activity of selfish transposable elements (TEs) through small-RNA mediated silencing. …

… Michael Winklhofer and Stefan Eder for their assistance in building our magnetoscopes
and for hosting Nathaniel Edelman in their laboratory. We thank the Bio-optics, Histology, …

Hybrids between species are often sterile or inviable. Hybrid unfitness usually evolves first in
the heterogametic sex—a pattern known as Haldane's rule. The genetics of Haldane's rule …

DNA introgressed from one species into another is typically deleterious at many genomic
loci in the recipient species. It is therefore purged by selection over time. Here, we use …

Identifying the traits causing reproductive isolation and the order in which they evolve is
fundamental to understanding speciation. Here, we quantify prezygotic and intrinsic postzygotic …

Transposable elements (TEs) play major roles in the evolution of genome structure and
function. However, because of their repetitive nature, they are difficult to annotate and …

Introgressed DNA is often deleterious at many loci in the recipient species’ genome, and is
therefore purged by selection. Here, we use mathematical modeling and whole-genome …

Heliconius butterflies (Lepidoptera: Nymphalidae) are a group of 48 neotropical species
widely studied in evolutionary research. Despite the wealth of genomic data generated in past …