What does ongoing hybridization observed in rock wallabies imply about species formation models?

Speciation in these environments might be more gradual or porous than previously modeled

The finding that hybridization—the mixing of genes between closely related species—is occurring among rock wallabies forces a re-evaluation of traditional evolutionary models. In classic models, once species diverge sufficiently for separate classification, reproductive isolation should prevent gene flow. The evidence suggests that for these specialized marsupials, evolutionary boundaries are more easily crossed than assumed. This implies that the process of speciation is often not marked by clean breaks but rather occurs gradually or allows for genetic 'leakage' across boundaries, meaning that some groupings considered distinct might share a more recent common ancestor than previously calculated.