Since as far as the memory of the human race goes, people have been falling in love, forming families, and having children. This view upon human life generalizes the basic nature of humans and introduces the creation of new generations based on reproduction. Whether in person, in print, or on television, you have probably heard phrases similar too: “Oh she looks just like you, but she definitely has your husbands eyes!” being spoken after the birth of a new child. As many of us, including myself, can verify towards, children, more often than not, will share resemblances with their parents. I, personally, am fascinated by the intricacy and complexity of DNA, however, in most science textbooks that you read, the historical discovery of DNA is more often than not credited to one or two particular people, but in reality, many scientists contributed to this discovery. This blog entry provides a quick overview of the history and beginning of DNA research based on some of the information I’ve found.
In the year of 1869, a Swiss physician by the name of Friedrich Meischer was the first to identify DNA after observing it in pus cells under a microscope. Because Meischer found the DNA within the nuclei of the cells, he decided to keep it simple and call it “nuclien”.
It wasn’t until about 50 years later when more was discovered about DNA, or “nucleids”. Phoebus Levene was a Russian-American biochemist who specialized in the field of the structure and function of nucleic acids. He was the first to characterize the differences between DNA and RNA and discover that DNA was made up of adenine, guanine, thymine, cytosine, deoxyribose and a phosphate group.
Technology was increasing during the nineteen hundreds, and there were more opportunities for scientists to explore and discover, hence discoveries began occurring much more frequently. By 1928, DNA had already been proved to carry genetic information. This was discovered by Frederick Griffith who was a British scientist specializing in microbiology.
More and more was being discovered about DNA and previous theories were being tested and revised. One such change was made towards Levene’s hypothesized structure of DNA. He thought the chain was short and the bases repeated in a fixed order, but in the year of 1937, William Astbury produced an x-ray diffraction of some DNA and proved Levene’s structure wrong.
As mentioned before, technology was increasing, and these rapid discoveries and revisions can verify to the opportunities that technology brings to science, for just 6 years later (1943), Oswald Avery, Colin Macleod and Maclyn McCarty conducted the “Avery- Macleod- McCarty experiment”. This experiment proved DNA to be a transforming principal and DNA’s role in heredity was verified in 1952 in the Hershey-Chase experiment. This experiment was performed by Alfred Hershey and Martha Chase and showed DNA to be a form of genetic material.
In 1953, James D. Watson and Francis Crick, American and English molecular Biologists, brought out the idea of DNA being structured in the form of a double helix model. This idea was published in the journal called Nature and was based upon an X-ray diffraction image taken by Rosalind Franklin and Raymond Gosling just a year before. Maurice Wilkins’ analysis of another experiment supported the double helix model of DNA as well. This discovery of the DNA structure won Watson, Crick and Wilkins a Nobel Prize in physiology.
More experiments were still being done afterwards and Crick, as well as many other scientists, did further research to build upon expanding and learning the mechanisms of DNA. But, as for the details of how DNA functions, well, that can be saved for another time.
Dahm, R. (2008). The First Discovery of DNA. In American Scientist. Retrieved April 6, 2011, from http://www.americanscientist.org/issues/feature/the-first-discovery-of-dna.
undefined. (2010). What is DNA?. In DNA sequencing. Retrieved April 6, 2011, from http://www.dnasequence.biz/what-is-dna.html.
Gregory, R. (April 13, 2007). The discovery of DNA. In Evolver zone Genomicron. Retrieved April 6, 2011, from http://www.genomicron.evolverzone.com/2007/04/discovery-of-dna/.