Topics: cellular metabolism, cell, genetic, development, taxonomy, phylogeny, unicellular eukaryotes, sponge, placozoan, cridarian, ctenophore, acoelomorpha, platyzoa, mesozoa, polyzoa, kryptrochozoa, mollusc, annelid, allied taxa, ecdysozoans, trilobites, chelicerates, myriapod, crustacean, hexapod, chaetognath, echinoderm, hemichordate, chordate, fish, tetrapod, amphibian, aminote, nonavian reptile, bird, mammal, support, protection, movement, homeostasis, digestion, nutrition, nervous coordination, nervous system, nervous coordination, sense organ, chemical coordination, immunity, animal behavior, animal distribution, animal ecology