100 years in … Biology
This year marks 100 years of IHS Chemical Week. To commemorate the anniversary, we would like to dedicate this series of blog posts to Chemical Week and their contribution to the field, by taking a look back at the last century in Science.
Last week we looked at the remarkable breakthroughs we have seen in physics and astronomy. This week we are turning our attention to the advancements in biology – space may be the final frontier, but human biology is the original unknown. It is the study challenging us to discover who we are and where we come from.
New discoveries in biology over the last century have completely transformed our previous understanding of the subject. From genetics to neuroscience, there have been breakthroughs in all areas, challenging the theories and beliefs of previous scientists.
After returning from holiday on September 3rd 1928, Fleming began sorting through used culture dishes containing Staphylococcus and noticed a blue-green mould. Out of curiosity, Fleming cultured the mould and found that it was able to kill a variety of different disease-causing bacteria. He identified the mould to be Penicillium, and so decided to name the active anti-bacterial substance ‘penicillin’.
Fleming thought penicillin would primarily be of interest to bacteriologists for the isolation of penicillin-insensitive bacteria in a mixed culture. He published his findings in the British Journal of Experimental Pathology but due to the difficulties in cultivation and isolation, Fleming abandoned his research soon after.
Several years later, in 1940, Howard Florey and Ernst Chain at the University of Oxford began their work with penicillin. They successfully isolated and made a concentrate of penicillin and eventually transferred the active ingredient back into water, allowing much larger quantities to be produced.
Florey and Chain soon began approaching American pharmaceutical companies to get penicillin manufactured on a large scale. By D-Day (6th June 1944) there was enough penicillin available for treatment of all bacterial infections that broke out among the troops.
It is widely accepted that the famously accidental discovery of penicillin is one of the most important moments in modern medicine. The widespread use and commercial success also led pharmaceutical companies to look for other natural products with antibacterial activity and so penicillin has indirectly led to the discovery of other antibiotics such as streptomycin and tetracycline.
Fleming, Chain and Florey shared the Nobel Prize for Physiology or Medicine in 1945 for their discovery and development of penicillin.
DNA was first discovered in 1869 by Swiss chemist Friedrich Miesche. In 1943 scientists Oswald Avery, Colin Macleod, and Maclyn McCarty deduced that deoxyribonucleic acid (DNA) was the substance responsible for carrying genetic information, but many scientists remained sceptical. The composition of DNA seemed too simple to carry such complex data with only four bases (A, T, C and G).
On 28th February 1953 Watson and Crick theorised the structure we know today, an anti-parallel two chain double helix stabilised by paired bases. The proposed structure was published in Nature on 25th April 1953 and has since been referred to as one of the most important discoveries of the 20th century.
A lesser-known contributor to the discovery of the double helix is Rosalind Franklin. Franklin was an X-ray crystallographer who successfully took an x-ray diffraction pattern (photo-51) of a DNA sample revealing its helical structure.
Knowing the structure of DNA has revolutionised biology and medicine and allowed the cracking of the genetic code. It has subsequently opened the way for the development of new techniques such as DNA sequencing, prenatal screening for disease genes, cloning, synthetic biology, genetic engineering of viruses or food, and accurate testing of physical evidence to convict or exonerate criminals.
Franklin died in 1958 of ovarian cancer so she was not eligible for the Nobel Prize but Wilkins (Franklin’s colleague), Watson and Crick went on to receive the Nobel Prizefor Medicine or Physiology in 1962.
Both Watson and Crick continued to work in genetics. Watson went on to play an instrumental role in directing the Human Genome Project between 1988 and 1992.
The Human Genome Project was undertaken in 1990, as an international effort to sequence the entire human genome. The aim was to support the research into human genetic diseases to find new approaches for diagnosis, treatment and prevention.
Throughout the project there were glimpses of how this project could lead to advances in medicine. In 1995 the Sanger centre located the BRCA2 gene, one of the genes linked with the risk of breast cancer and in 1993 a US team identified the MSH2 gene associated with colon disease.
In April 2003 researchers announced that they had a high-quality version of essentially the entire human genome. They made the sequence and the tools to analyse the data freely available on the Internet.
The Human Genome Project has inspired many others to begin ambitious, collaborative projects to analyse the Human Genome, for example the international HapMap project which aims to chart the differences in SNPs between different groups to gain a better understanding of genetic predispositions. ENCODE(Encyclopaedia of DNA elements) was also started in 2003 and aims to determine the role of every piece of DNA in the human genome.
Now that there is so much data available, the challenge is in understanding and using it to learn more about the human genome. The human genome project and other data will be instrumental in learning more about the link between genetics and human disease, and will undoubtedly play a role in discovering possible cures.
Overall the achievements we have discussed have each completely revolutionised the study of biology. The new information and understanding that has been gained in the last 100 years is remarkable and the potential for the next century appears even more exciting.
For more achievements in science make sure to catch up on the rest of this series with 100 years in… Astronomy and Physics, Tech and Chemistry
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