Milestones in order. This is history, not a weekly activity grid.
- Ivanovsky's filter
- Beijerinck's fluidum
- Rous sarcoma
- Stanley crystallises TMV
- Hershey–Chase
- Polio vaccine licensed (US)
- HIV identified
- SARS-CoV outbreak
Darker cells mean a higher score for this topic on that metric.
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Quick answers
Where should I start with Viruses?
Read Identity → How they live → Body & health, then use compare rails.
Is this page advice for Viruses?
Public-health education — not a care plan, prescription, or outbreak briefing.
What does the local lens add?
It names everyday desks for Tree of microbes before English norms look universal.
Are the scores a ranking of Viruses?
No — editorial 0–100 browsing aids inside this atlas only.
How do I compare Viruses to neighbours?
Use related cards and best-of / quiz rails after the first three chapters.
Which chapter is densest?
How they live and Body & health carry mechanisms; skim Identity first.
People knew smallpox and rabies for centuries without a particle theory. Porcelain filters in the 1890s showed something smaller than bacteria could still transmit disease.
The twentieth century added crystals, bacteriophage genetics and electron microscopes. Each tool made 'filterable fluid' look more like organised matter.
Timeline
Dmitri Ivanovsky shows tobacco mosaic disease passes a bacterial filter — a founding observation of virology.
Martinus Beijerinck calls the agent contagium vivum fluidum — living, fluid, and not a cultured bacterium.
Peyton Rous transmits a hen tumour with a filtrate, linking some cancers to viruses decades before oncogenes were named.
Wendell Stanley crystallises tobacco mosaic virus, shocking biologists who thought 'alive' could not be a crystal.
Phage blender experiments show DNA, not protein, is the hereditary material of T2 bacteriophage.
Jonas Salk's inactivated vaccine enters wide use; Albert Sabin's oral vaccine follows. Incidence collapses where campaigns hold.
Luc Montagnier's group isolates the retrovirus later named HIV; the 2008 Nobel recognised that lineage of work.
A novel coronavirus spreads from a hotel cluster into hospitals. It previews later coronavirus surveillance.
Viral history is also the history of cities, farms and travel — not only famous names in a lab notebook.
Keep exploring
More in Tree of microbes
Bacteria
Single-celled prokaryotes with cell walls — the oldest widespread life form, and both partners and pathogens.
Familiarity 95Fungi
A eukaryotic kingdom of yeasts, moulds and mushrooms — chitin walls, external digestion, partners of plants.
Familiarity 80Archaea
A prokaryotic domain that is not bacteria — methanogens, extremophiles and no known human pathogens.
Familiarity 35Bacteriophages
Viruses that infect bacteria — Earth's most abundant biological entities, and a concept-level idea in medicine.
Familiarity 42Protozoa
Motile unicellular eukaryotes — a teaching grade that includes pond ciliates and a minority of serious parasites.
Familiarity 58