The Human Genome Project Was Declared Complete in 2003

The tiny remaining difference accounts for the variation between individuals.

Adenine, thymine, cytosine and guanine pair up to form the rungs of the double helix.

That is roughly 3.1 billion of the chemical letters that make up a person's DNA.

Their model relied on X-ray images by Rosalind Franklin, and Watson, Crick and Maurice Wilkins won the Nobel Prize in 1962.