Rapid miocene-pliocene dispersal and evolution of Mediterranean rajid fauna as inferred by mitochondrial gene variation.
Rajidae (colloquially known as skates and rays) experienced multiple and parallel adaptive radiations allowing high species diversity and great differences of species composition between regional faunas. Nevertheless, they show considerable conservation of bio-ecological, morphological and reproductive traits. The evolutionary history and dispersal of North-east Atlantic and Mediterranean rajid fauna were investigated throughout the sequence analysis of the control region and 16S rDNA mitochondrial genes. Molecular estimates of divergence times indicated recent origin and rapid dispersal of the present species. Compared with the ancient origin of the family (Late Cretaceous), the present species diversity arose in a relatively narrow time-window (12 Myr) from Middle Miocene to Early Pleistocene, likely by speciation processes related to dramatic geological and climatic events in the Mediterranean. Nucleotide substitution rates and phylogenetic relationships indicated Mediterranean endemic skates derived from sister species with wider distribution during Late Pliocene-Pleistocene. Skate phylogeny and systematics obtained using mitochondrial gene variation were largely consistent with those based on morpho-anatomical data.
Valsecchi
E
E
Istituto Centrale per la Ricerca Applicata al Mare (ICRAM), Via di Casalotti, Roma, Italy.
Pasolini
P
P
Bertozzi
M
M
Garoia
F
F
Ungaro
N
N
Vacchi
M
M
Sabelli
B
B
Tinti
F
F
D000818:Animals; D001483:Base Sequence; D017931:DNA Primers; D004272:DNA, Mitochondrial / Q000235:genetics; D003710:Demography; D019143:Evolution, Molecular; D014644:Genetic Variation; D005843:Geography; D008522:Mediterranean Sea; D008969:Molecular Sequence Data; D010802:Phylogeny; D017422:Sequence Analysis, DNA; D012860:Skates, Fish / Q000235:genetics*; D013045:Species Specificity
D017931:DNA Primers; D004272:DNA, Mitochondrial