Maggie's Farm

One quote from the non-technical post at Neurophilosophy:

A comparison of the DNA sequences from the 36 sea sponge genes with the homologous sequences from humans, Drosophila melanogaster (fruit flies) and Nematostella vectensis (a cnidarian with a simple nervous system consisting of a loose network of nerves) revealed striking similarities between the genes in all four species. One gene, called dlg, encodes a crucial component of the post-synaptic density scaffold. The protein product of that gene contains a number of regions that form the protein-protein bonds that hold the scaffold together. The segment of the dlg gene encoding these binding regions was found to be highly conserved - the DNA sequences in the sea sponge gene were identical to the human sequences. This suggests that in the sea sponge these proteins interact in exactly the same way as they do in the human postsynaptic density.