Several recent studies have compared small mammal community structure acros
s multiple deserts on different continents. These studies have tacitly assu
med that variation in community structure was greater between continents th
an within, and so have nor evaluated variation across desert regions within
continents. I evaluated several metrics of community structure and a model
of community assembly for four desert regions in North America - the Great
Basin: Mojave, Sonoran, and Chihuahuan Deserts - in order to explicitly co
mpare these metrics across these deserts. Additionally, I compared these re
sults with similar analyses conducted on two desert regions in central Asia
- the Gobi Desert and the Turan Desert Region - to evaluate th; relative m
agnitude of intra- vs inter-continental variation. Although the patterns ob
served are complex, they demonstrated marked heterogeneity in desert small
mammal communities within North America. However, this heterogeneity is muc
h less than that observed in inter-continental comparisons, in which Asian
and North American deserts differ markedly. These results agree with other
recent studies providing limited or no support for the existence of substan
tial convergence in community characteristics or ecological function across
geographically distant regions. Rather, the results support thr hypothesis
that the common evolutionary history of faunas in globally disjunct landma
sses has had a. stronger influence on the evolution of communities and faun
as than do regional variations in climate, physiography. etc. Whereas a com
mon ecological setting may have large impacts on some Facets of organismal
structure (e.g., bipedalism in desert small mammals). common evolutionary h
istory appears to have a more profound influence on local dynamics.