Divergence and Loss of Msx Groucho-binding Domains (MH1N and MH1C). The ancestral sequences of MH1N and MH1C were inferred for four key ancestors (solid circles) based on sequences found in extant animals (right). Single alignment gaps were removed from mouse Msx3 and Nematostella Msx (triangles). Estimated evolutionary distances were calculated from each ancestor to its descendent(s) (ΔMH1N and ΔMH1C). Where MacClade inferred multiple possible ancestral states, the range of possible evolutionary distances is given. The evolutionary distance between MH1N and MH1C was calculated for each ancestor and each extant animal (1N vs. 1C). Distance calculations were not made to MH1C in Msx2 and Msx3 because no significant match to the MH1C motif was identified in these proteins.