Many synapse components, neural fate and patterning genes, and neurotransmitters are found in both cnidarians and ctenophores, which have nerve nets, but not in sponges, which do not. Ctenophores are currently believed to be the outgroup to cnidarians, bilaterians, and sponges, casting doubt on the origins of nervous systems. What are two plausible scenarios consistent with these observations, and how could one experimentally distinguish between them?

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The Answer of Many synapse components, neural fate and patterning genes, and neurotransmitters are found in both cnidarians and ctenophores, which have nerve nets, but not in sponges, which do not. Ctenophores are currently believed to be the outgroup to cnidarians, bilaterians, and sponges, casting doubt on the origins of nervous systems. What are two plausible scenarios consistent with these observations, and how could one experimentally distinguish between them?

Many Synapse Components, Neural Fate and Patterning Genes, and Neurotransmitters