Adenine, cytosine, guanine and thymine. You may know them better as A, C, G and T. In the early 1950s, these four nucleotides meant nothing to anyone outside of a few dedicated scientists. But 50 years ago tomorrow, James Watson and Francis Crick found what Crick called “the secret of life.”

Those little compounds, held together with strands of sugars and proteins, make up the double helix of deoxyribonucleic acid, DNA. On Monday, USA Today ran a set of articles about the scientists that found these blueprints and the people whose ideas influenced them, and what scientists have done so far and are doing today with the building blocks of life. Those articles, and the commemorative Web site www.dna50.org, are where much of this information came from.

Any school-age student today — or anyone who has seen “Jurassic Park” — has an idea of what this structure does or, as far as the movie is concerned, what science fiction would like it to be able to do. While bringing creatures back to life may be a ways off, smaller steps are being taken every day. It is amazing that people would even consider accepting the premise, based on something that was virtually unknown a half-century ago.

Today, scientists working with DNA say they have barely begun to scrape the surface of what can be done. But the list of what they have already found and done is remarkable.

DNA has been used to convict and exonerate criminals who committed crimes weeks or decades ago. The pieces of genetic material responsible for diseases from Down syndrome to Parkinson’s disease have been located. Pieces of DNA have been cut and pasted from one organism to another or, in the case of cloning, copied and pasted.

In the past decade, scientists have been working up the DNA chain, so to speak, in decoding the entire genome for more and more complex organisms, from yeast (1996) to a nematode worm (1998) to the entire 22nd human chromosome (1999) to a fruit fly (2000). USA Today reports that on April 14, 11 days before the 50th anniversary of the publication of the double helix in the British journal Nature, researchers will announce the decoding of the entire human genome, “the genetic blueprint that distinguishes a man from a mouse.”

This vital code makes every person what he or she is, yet the 3 billion letters of code can be carried around on a device that uses a decidedly different code: Wired magazine reported in November that Dr. Will Gilbert carries around the entire genome on an Apple iPod. The formula for your hair and eye colors can share space with your choice of music.

The discovery of the double helix structure did not come independently of other studies. There were many discoveries beforehand that were necessary first. Research by Gregor Mendel into the heredity of peas in the 1850s revealed the existence of genes, but up until the early 20th century scientists thought proteins, with 20 amino acids, made the genes, instead of DNA and its four nucleotides. Once biologists proved genes were made of DNA, the race was on to find out how it was arranged.

But, according to USA Today, “it was like being handed a pile of wood and being asked to deduce the structure of a three-story building.”

Watson and Crick teamed up in England and visited the lab of Rosalind Franklin. There, Crick saw an X-ray crystallographic photograph of DNA, and he could see a spiral structure. Working for another year, the two used physical representations to show the twisted ladder of life — and then published their findings in an essay not much longer than this column.

Fifty years later, genetic manipulation is a thing of the present and immediate future. But it is not without controversy. Placing strands of DNA in plants to make them immune to diseases — genetically modified organisms — are under heavy debate. The possibility of having babies with “designer genes” is poised to leave the realm of unbelievable science fiction.

All it takes to realize the impact of this discovery at Iowa State is to take a walk to the north side of campus. The Molecular Biology Building pays tangible tribute to this tiny structure. Strands of the double helix climb up the corners of the outside walls, and “G-Nome” statues symbolize the four nucleotides that make the stuff that plants and animals are made of.

Jeff Morrison is a junior in journalism and mass communication and political science from Traer. He is the wire editor of the Daily.