Natural cases of salamander hybridization suggest a consistent relationship between genetic distance and reproductive isolation across tetrapods
Hybridization between populations along the path to complete reproductive isolation can provide snapshots of speciation in action. Here, we present the first comprehensive list of natural salamander hybrids and estimate genetic distances between the parental hybridizing species using a mitochondrial and nuclear gene (MT-CYB and RAG1). Salamanders are outliers among tetrapod vertebrates in having low metabolic rates and highly variable sex chromosomes. Both of these features might be expected to impact speciation; mismatches between the mitochondrial and nuclear genomes that encode the proteins ...
(For more, see "View full record.")