We found that the number of species in each category was not randomly-distributed among vertebrate groups, or the families within those groups. The importance of each homogenizing mechanism (introduction or extinction) differs among each vertebrate group and the families within. Vertebrate groups and families with both more successfully introduced and IUCN-listed species than expected are most susceptible to the homogenization process because they could be homogenized through both mechanisms. Families with more successfully introduced or IUCN-listed species than expected contribute to the homogenization process though the respective mechanism. The use of trade data allowed us to assess directly the impact of human influence on the homogenization process for all the vertebrate groups we analyzed, an important factor affecting the global and taxonomic patterns of homogenization. When making conservation recommendations regarding restriction of trade due to its contribution to the homogenization process, specific attention should be given to those vertebrate groups and families that contain a disproportionate number of species that are traded, successfully introduced, and/or IUCN-listed.