  We present results contrasting food webs constructed using the same model
where the source of species was either evolution or immigration from a
previously evolved species pool. The overall structure of the webs are
remarkably similar, although we find some important differences which mainly
relate to the percentage of basal and top species. Food webs assembled from
evolved webs also show distinct plateaux in the number of tropic levels as the
resources available to system increase, in contrast to evolved webs. By
equating the resources available to basal species to area, we are able to
examine the species-area curve created by each process separately. They are
found to correspond to different regimes of the tri-phasic species-area curve.
