Figure 2. Scale-dependent sampling effects on
phylogenetic distance. (A-B) Nearest phylogenetic distance (NPD) of
introduced species (63 species successfully established in 50 regions
Worldwide) to native species estimated at different spatial scales; (C)
species randomly sampled from the entire avian phylogeny (n=9,993), the
subset that has been introduced in regions outside their native range
(n=962) and those from the subset that have become successfully
established in the new region (n=443); and (D-E) species of the
biogeographic realm from where most introduced species originated
(Palearctic) and realms where those have more frequently been introduced
(Nearctic and Australian). Codes: IC = invaded communities, NIC =
non-invaded communities, REG = regional level, COU = country and CON =
continental.