A New Genetic Code?
An old Discovery News article has recently been making its rounds on Facebook, which was claiming that “new nucleotides” were identified in human DNA. Users were quick to rant and rave about how game-changing this piece of news is. I read claims about how they’d need to retake biology courses now and how this could have implications on artificial life.
DNA is composed of four canonical bases. Canonical, because they are the classic bases in Watson and Crick’s double helix. That is, four chemical letters that compose genes—adenine (A), thymine (T), guanine (G), and cytosine (C). These are the A’s, T’s, G’s, and C’s you see in biology textbooks. What users took the news to be was that there were new letters to add to these. To be fair to those misled, the title was technically accurate (New Nucleotides Identified in Human DNAfrom Discovery News on July 27, 2011). There are two new nucleotides previously unknown. However, contrary to the subsequent speculations of those I read, the discovery doesn’t demolish or revolutionize anything that we’ve already known about what genes are. A’s will still always pair with T’s and G’s will always pair with C’s. There are no secret letters strewn throughout the genome (at least, for life here on Earth).
Read the full article on the Filipino Freethinkers website.
On this day in 1953, Francis Crick and James Watson discovered the structure of deoxyribonucleic acid (DNA) using unacknowledged photographs and research by their colleague Rosalind Franklin. They had considered many other candidates for the structure, including single and triple strand helices before deciphering the structure. They would publish a paper that same year describing their discovery, but the significance of the discovery was largely overlooked by the general public for over a year. Today it stands as one of the most remarkable milestones in the history of science.
The word deoxyribonucleic is a compound word formed around the main root word ribose, which arrived in English in 1892 via the German word Ribose which was itself borrowed from the English word of 1880 arabinose, a sugar derived from gum arabic. The word nucleic comes from the Latin word nucleus meaning a kernal around 1700, from the Latin diminutive nucula meaning a little nut. It did not take the meaning of a central characteristic or attribute until 1762. It wasn’t applied to cellular structures for another 70 years around 1862. The -oxy- root comes from the Ancient Greek word οχυς oxys meaning sharp or pointed (sharing the earlier common root word that gave the Latin word acer with the same meaning and ultimately the English word acid). The de- prefix is a Latin preposition meaning down from, off or away from, used mainly in English compound words as a privative, meaning that something lacks something.
Double Helix - The DNA Years
Double Helix - The DNA Years 1 of 12 - BBC Science and History Documentary This two-part series (here in 12 parts) tells the story of a 50-year-old quest to discover the secret of human nature hidden in our DNA. We can now transfer genes from one species to another, creating pigs with human genes and crops that make their own pesticides. Human embryos are screened for genetic illnesses. And all convicted criminals in the UK have their DNA fingerprints kept on file. Genetics opens many doors, but it also raises complex ethical questions. From the discovery of the structure of the DNA in 1953, through to the completion of the human genome map, Double Helix paints an extraordinary new picture of human nature, showing the truth of what DNA can tell us about ourselves.
