genome

In 1920, German botanist Hans Winkler created the word genom (later genome in English) by combining gen (gene) and -ome (a suffix denoting 'whole' or 'group,' from Greek soma, body). He needed a single term for the complete set of hereditary material in an organism—everything needed to build and run a living creature.

Before Winkler, biologists knew about genes but not about genomes. They understood inheritance was discrete (Mendel's laws) but thought genes might be scattered in bits throughout the cell. Winkler proposed something more radical: genes clustered together, and the total cluster was the genome. The complete instruction set.

The word caught on slowly at first. For fifty years, genome remained a technical term used mostly by plant biologists. Then DNA's structure was cracked in 1953, and suddenly the genome became everything: the molecule itself, the sequence, the blueprint. In 1977, Frederick Sanger sequenced the first genome—a virus. In 2003, the Human Genome Project finished, publishing three billion base pairs.

The word genome is now ubiquitous. Genomes of extinct species are being reconstructed from ancient DNA. Your own genome can be sequenced for a few hundred dollars. The word Winkler coined carries an enormous weight: it names the difference between one human and another, between humans and animals, between life and non-life.