What’s the oldest data format in the world? It’s not any of the ones that computer engineers developed in the 20th century, or even ones that telegraph engineers created in the 19th. Far older than those — by billions of years — is the DNA nucleotide sequence. We can think of it as a simple base-4 encoding of arbitrary length.
According to the usual, somewhat simplified, description, a DNA molecule is a double helix, with its backbone made of phosphates and sugars, and four types of nucleotides forming the sequence. They are adenine, guanine, thymine, and cytosine, or A, G, T, and C for short. They’re always found in pairs connecting the two strands of the helix. Adenine and thymine connect together, as do guanine and cytosine.
DNA for data encoding
That’s as deep as I care to go, since biochemistry is far away from my areas of expertise. What DNA does is fantastically complicated; change of few bits and you can get a human or a chimpanzee. But as a data model, it’s fantastically simple.