“…The arguments for dispersal (e.g., Gross, 1987;McDowall, 1970McDowall, , 1988McDowall, , 2001McDowall, , 2002Berra et al, 1996;Keith, 2003), vicariance (e.g., Rosen, 1974;Croizat et al, 1974), or some combination of the two (e.g., Choudhury & Dick, 1998) as explanations for the distribution of diadromous taxa, especially the antitropical salmoniform fishes, have been debated extensively. Likewise, broad geographic ranges have been interpreted as explicit evidence of dispersal (e.g., McDowall, 2001McDowall, , 2002, of vicariance (e.g., Rosen, 1974), or of either dispersal or vicariance (Leis, 1984).…”