Summary: Comparative phylogeography as an integrative
approach to historical biogeography
Phylogeography has become a powerful approach for elucidating contemporary geographical patterns
of evolutionary subdivision within species and species complexes. A recent extension of this approach
is the comparison of phylogeographic patterns of multiple co-distributed taxonomic groups, or
`comparative phylogeography.' Recent comparative phylogeographic studies have revealed pervasive
and previously unrecognized biogeographic patterns which suggest that vicariance has played a more
important role in the historical development of modern biotic assemblages than current taxonomy
would indicate. Despite the utility of comparative phylogeography for uncovering such `cryptic
vicariance', this approach has yet to be embraced by some researchers as a valuable complement to
other approaches to historical biogeography. We address here some of the common misconceptions
surrounding comparative phylogeography, provide an example of this approach based on the boreal
mammal fauna of North America, and argue that together with other approaches, comparative
phylogeography can contribute importantly to our understanding of the relationship between earth
history and biotic diversi®cation.
Area cladistics, comparative phylogeography, historical biogeography, vicariance.
In a recent guest editorial Humphries (2000) presented an overview of historical biogeography.