Units in Biogeography

In the past two decades, vicariance biogeography has become a major subdiscipline of biogeography. The subject of vicariance biogeography is the study of area relationships (e.g., Nelson and Platnick, 1981; Morrone and Crisci, 1995; Humphries and Parenti, 1999). An important step in the investigation of area relationships is the transformation of a taxon cladogram into an area cladogram. Different delimitations of unit areas can result in different outcomes