Biology Experiments

Interactive simulations of the five experiments that built modern molecular biology. Each folder is a self-contained web app — open it from the sidebar to launch.

Experiments

• Griffith Transformation (griffith-transformation/) — 1928. Heat-killed virulent pneumococci can transform live harmless strains into killers. The first hint that something carries heredity between cells.
• Hershey-Chase (hershey-chase/) — 1952. Radioactively label phage protein (³⁵S) and DNA (³²P), blend, spin, and watch only the DNA enter the bacterium. DNA, not protein, is the genetic material.
• Mendel's Peas (mendel-peas/) — 1865. A Punnett square simulator. Cross any two parental genotypes and watch the F1 and F2 ratios emerge generation by generation.
• Meselson-Stahl (meselson-stahl/) — 1958. Grow E. coli in heavy nitrogen (¹⁵N), shift to light (¹⁴N), and watch DNA bands settle in a density gradient. The proof that replication is semiconservative.
• Miller-Urey (miller-urey/) — 1953. Spark a flask of methane, ammonia, hydrogen, and water vapor for a week and watch amino acids accumulate. Life's building blocks from a primordial soup.

All apps run entirely in the browser. No network, no dependencies.

Implementation notes

Each experiment is a directory with an index.html file. Built with vanilla JS + Canvas — zero build step, zero external libs. Open the HTML directly in any browser if you want to hack on it.

Why these five

These are the experiments that turned biology from a descriptive science into a molecular one. Read together they answer four questions in order:

1. Is heredity carried by something physical? (Griffith)
2. Which molecule? (Hershey-Chase)
3. How does it copy itself? (Meselson-Stahl)
4. Where did it come from? (Miller-Urey)

Mendel sits at the front because the math of inheritance — dominant/recessive ratios — is what made the rest interpretable.