Panbiogeography and rails of the genus Gallirallus

Abstract

An investigation of flightlessness in the Rallidae led me to question the theories of Olson (1973); that all rails in the genus Gallirallus were distributed over their present range by recent flighted dispersal; and that flightlessness is a recent process conferred by the paedomorphic process neoteny. The current distribution of some members of Gallirallus (Olson 1973a) are interpreted using the panbiogeographic method of Croizat (1958, 1958a). This method indicates that the distribution of some rails is similar to other biota. I suggest the group may be ancient, and its distribution the result of vicariism. Consequently, the evolution of flightless morphology need not be fast, and the flightless rails on different land masses could be the result of flightless radiations.