Biology
CRISPR
One of the most transformative technologies in modern biology started out as nothing more than a bacterium's own built-in defense system against viruses.
Evolution
A theory that doesn't claim organisms get objectively "better" over time — just that whatever happens to work in a given environment tends to stick around.
The Human Genome
A complete genetic blueprint that took an international research effort over a decade and roughly $3 billion to first sequence — now doable for under $1,000.
Viruses
A microscopic particle so stripped-down that scientists still debate whether it even counts as truly "alive" at all.