bionet.*
The Usenet hierarchy for biologists, started in the late 1980s and mirrored to mailing lists so that labs without Usenet could join in.
The system went by the name BIOSCI and was early in treating the network as a tool for a research discipline rather than for computer people. Groups covered everything from molecular-biology methods and reagents to sequence databases, job postings and individual model organisms. Every group also existed as a mailing list, and the same post went out both ways.
For researchers without a sysadmin of their own, this was often the first brush with anything like a live global discussion — a question about why a PCR protocol kept failing could collect answers from three continents overnight. Web forums and later social media took over, but the hierarchy showed how a field could put the network to work well before the web arrived.