Next-generation phylogeography of the banded newts (Ommatotriton): A phylogenetic hypothesis for three ancient species with geographically restricted interspecific gene flow and deep intraspecific genetic structure

Hybrid zone analysis confirms cryptic species of banded newt and does not support competitive displacement since secondary contact

“…We confirm the presence of a hybrid zone between two cryptic species of banded newt and pinpoint its location (Figure 1 ). Previous studies could not determine if the two met in nature, let alone hybridized (Bülbül & Kutrup, 2013 ; van Riemsdijk et al, 2017 , 2022 ). However, localities from within the previously unsampled region were already known from the literature (Borkin et al, 2003 ), and an anthropogenic hybrid swarm outside the native range supported hybridization potential (van Riemsdijk et al, 2018 ).…”

“…To design nuclear DNA SNP markers, we took sequence data from 59 nuclear DNA markers identified by van Riemsdijk et al ( 2022 ) as being species‐diagnostic for O. nesterovi versus O. ophryticus (i.e., that did not share alleles in populations sampled away from the putative hybrid zone). Out of these, 53 markers contained SNPs with fixed nucleotide differences for O. nesterovi versus O. ophryticus (Table S2 ).…”

“…Up until recently, the banded newt was considered a single species (Borkin et al, 2003), but recent studies propose a treatment as three distinct species (Bülbül & Kutrup, 2013;Frost, 2021;Litvinchuk et al, 2005;Üzüm et al, 2019;van Riemsdijk et al, 2017). These species are characterized by highly diverged mtDNA and nuDNA clades (van Riemsdijk et al, 2017(van Riemsdijk et al, , 2022.…”