Short communication Conflicting phylogenetic signal of nuclear vs mitochondrial DNA markers in midwife toads (Anura, Discoglossidae, Alytes): Deep coalescence or ancestral hybridization? H. Gonc ¸alves a,b,c, * , I. Martı ´nez-Solano d,1 , N. Ferrand a,b , M. Garcı ´a-Parı ´s c a CIBIO, Centro de Investigac ¸a ˜o em Biodiversidade e Recursos Gene ´ ticos, Campus Agra ´ rio de Vaira ˜o, 4485-661 Vaira ˜o, Portugal b Departamento de Zoologia e Antropologia – Faculdade de Cie ˆncias da Universidade do Porto, Prac ¸a Gomes Teixeira, 4099-002 Porto, Portugal c Museo Nacional de Ciencias Naturales, CSIC, Jose ´ Gutie ´rrez Abascal, 2, 28006 Madrid, Spain d Museum of Vertebrate Zoology, 3101 Valley Life Sciences Bldg., Berkeley, CA 94720-3160, USA Received 30 August 2006; revised 17 February 2007; accepted 1 March 2007 Available online 12 March 2007 1. Introduction Amphibians, as well as other organisms with limited dis- persal abilities and a prevalent vicariant mode of specia- tion, are particularly prone to reticulate when two previously isolated lineages establish secondary contact (e.g. Garcı ´a-Parı ´s et al., 2003; Weisrock et al., 2005; Mulc- ahy et al., 2006; Weisrock and Larson, 2006; but see Hos- kin et al., 2005). One case that exemplifies this problem is the long-standing debate on the phylogeny of midwife toads (Alytes Wagler, 1829), resulting from the partial lack of congruence among mtDNA, morphology, and allozyme based hypotheses (Arntzen and Garcı ´a-Parı ´s, 1995; Fromhage et al., 2004; Martı ´nez-Solano et al., 2004). Midwife toads present an exclusive reproductive mode including an elaborated parental care, in which the male carries a string of eggs on its hindlimbs until eclosion. The genus Alytes comprises five species distributed in three subgenera, all of them restricted to the extreme western Palearctic region (Fig. 1): Alytes (Alytes) obstetricans (Laurenti, 1768), widely distributed in western Europe, with four currently recognized subspecies (Fig. 1), Alytes (Ammoryctis) cisternasii Bosca ´, 1879, endemic to the cen- ter and southwest of the Iberian Peninsula, Alytes (Bale- aphryne) muletensis (Sanchiz and Adrover, 1979) from the island of Mallorca in the Balearic archipelago, Alytes (Baleaphryne) dickhilleni (Arntzen and Garcı ´a-Parı ´s, 1995), endemic to the southeastern Iberian Peninsula, and Alytes (Baleaphryne) maurus Pasteur and Bons, 1962, which is patchily distributed in the mountains of northern Morocco (Bons and Geniez, 1996; Grossenbacher, 1997; Crespo, 1997; Garcı ´a-Parı ´s and Arntzen, 2002; Roma ´n, 2002). The discovery of ‘‘living-fossils’’ (Sanchiz and Adrover, 1979; Alcover and Mayol, 1980) and the application of molecular techniques (Arntzen and Garcı ´a-Parı ´s, 1995; Garcı ´a-Parı ´s and Martı ´nez-Solano, 2001; Martı ´nez-Solano et al., 2004) resulted in taxonomic changes in the group, including description of new species and subspecies and changes in the taxonomic status of some of them. Several studies have tried to clarify the phylogenetic relationships among the species of the genus. Sanchiz (1984) and Max- son and Szymura (1984) proposed phylogenetic hypotheses based on morphological characters of the skeleton and on immunological data, respectively. Based on protein electro- phoretic data, Arntzen and Garcı ´a-Parı ´s (1995) placed Alytes dickhilleni as the sister group of Alytes muletensis and Alytes obstetricans as the sister taxon of the clade A. muletensis + A. dickhilleni. Altaba (1997) reanalyzed the dataset of Arntzen and Garcı ´a-Parı ´s (1995) using a differ- ent coding scheme and found support for a sister-group relationship between A. obstetricans and A. dickhilleni (but see Arntzen and Garcı ´a-Parı ´s, 1997). Recently, Fromhage et al. (2004) and Martı ´nez-Solano et al. (2004) used mtDNA sequences to construct a phylogenetic hypothesis of Alytes including A. maurus, which was recov- ered as the sister taxon to A. muletensis or to (A. muleten- sis + A. dickhilleni). Martı ´nez-Solano et al. (2004) included 1055-7903/$ - see front matter Ó 2007 Elsevier Inc. All rights reserved. doi:10.1016/j.ympev.2007.03.001 * Corresponding author. Address: CIBIO, Centro de Investigac ¸a ˜o em Biodiversidade e Recursos Gene ´ticos, Campus Agra ´rio de Vaira ˜o, 4485- 661 Vaira ˜o, Portugal. Fax: +351 252661780. E-mail address: hgoncalves@mail.icav.up.pt (H. Gonc ¸alves). 1 Present address: Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, 75 N Eagleville Rd., Unit 3043, Connecticut 06269-3043, USA. www.elsevier.com/locate/ympev Molecular Phylogenetics and Evolution 44 (2007) 494–500