There is striking domain level evolution present in the Hedgehog family of proteins, the N-terminal domain (Hedge) and the C-terminal domain (Hog), that were later spliced together into a single transcriptional unit. The Hog domain contains a sequence called Hint (Hedgehog INTein), which is similar in sequence and function to bacterial and fungal inteins. The Hog domain is present in many eukaryotic branches, i.e. red algae, mosses, dinoflagellates, jakobids, and other single cell eurkaryotes. Choanoflagellates contain a gene named hoglet that also encodes the hedgehog C-terminal domain Hog domain. However, Choanoflagellates and lower eukaryotes do not contain any regions similar to the hedge domain, suggesting that hog evolved first. Poriferans have both hedge-like proteins (termed hedgling) and hog-like proteins, but they exist as two completely separate transcriptional units. Cnidarians contain the hedgling and hog genes, but also have a complete hedgehog gene, indicating that hedge and hog were spliced into hedgehog after the last common ancestor of poriferans and cnidarians.