title: Is there an earlier phylogenetic precursor that is common to both the nervous and endocrine systems?
mesh_terms: D000818:Animals; D002450:Cell Communication; D004702:Endocrine Glands / Q000032:analysis*; D006728:Hormones / Q000032:analysis*; D006801:Humans; D009420:Nervous System / Q000032:analysis*; D018377:Neurotransmitter Agents / Q000032:analysis; D010455:Peptides / Q000032:analysis*; D010802:Phylogeny; D010944:Plants / Q000032:analysis
chemical_list: D006728:Hormones; D018377:Neurotransmitter Agents; D010455:Peptides