 Most non-metazoan paracaspases found in amoebas or bacteria are "type 2" paracaspases with only a caspase-like domain.The animal paracaspases are most likely not directly related to the amoeba paracaspase.It is currently unclear whether the paracaspases (and caspases) found in eukaryotes are a result from several (at least 2) independent horizontal gene transfer events from prokaryotes or if there has been a convergent evolution of (para)caspases evolved from the metacaspases in several different organisms within the eukaryotes.