You are the Google search engine.
Given a query, you need to generate five useful documents for the query.

The user is trying to answer the question: "the earliest evolution of the nervous system (a nerve net) occurred in?" whose answer is animals like cnidaria.
Each document should contain about 30 words, and these documents should contain useful information.

Query: earliest evolution of the nerve net nervous system
Useful Output:

Doc 1: We propose that neurons and nervous systems evolved among thin, motile, microbe-eating animals during the Ediacaran period (635–543 million years ago).
Doc 2: Once it was established by Romanes for jellyfish and by Parker for sea anemones that the nerve net is the first evolutionary manifestation of an organized
Doc 3: Early theories on the evolutionary origin of the nervous system argued for a three-stage process: first, the development of non-nervous “
Doc 4: Ctenophores (commonly known as comb jellies) are among the earliest branching extant lineages of the an- imal kingdom. Here, I present a brief.
Doc 5: Nerve net, primitive nerve arrangement forming the entire nervous system of many cnidarians and a part of more advanced nervous systems.