Contributions of Thomas Hunt Morgan
Thomas Prum
MWF 11:00

There were many major contributions made in the field of biology and some of which were discovered by geneticist Thomas Hunt Morgan. Born on September 25, 1866, educated at the University of Kentucky and obtained a Ph.D. at John Hopkins University, was the first to discover that the gene located to specific positions on the chromosome is the control for certain types of development in different or similar traits in each individual offspring. His major contributions were made in the form of sex linkage, how certain genetic traits are passed on to different offspring, and the location of genes on chromosomes.
Morgan’s discoveries about genes and their locations on chromosomes helped lead biology into the form of an experimental science. It allowed for many different experiments to be performed for the sake of further research and findings about genetics that were not available beforehand. This made it possible to answer many questions regarding the structure and function of genes. What is their chemical nature? How do they duplicate? How do genetics affect cells?
Morgan and his students answered these questions and many more questions similar to them.
More questions were answered by other scientists under the influence of Morgan, and his discoveries basically set the program in biological work for later years.
Much of Morgan’s primary studies had to do with the reproduction of animals and just how he can relate that into cell mutation and development. At the time, he used animals like rats and mice to conduct his experiments, but soon found that they reproduced much too slowly to be effective in the study of heredity. This led Morgan to studying the fruit fly because they were much easier to manage and reproduced at a much faster rate. Fruit flies were easy to raise in a laboratory and thousands could be collected in small containers. They could produce new generations every twelve days and are fertile all year long. It is simple to tell the sexes apart, making it easier to determine any kind of mutations in new generations of fruit flies.

Morgan worked with fruit flies with the intention of breeding many generations of flies hoping that one would end up looking different than the rest. He wanted to see if any flies at all had gone through a mutation or change when being developed. He was unsuccessful for many years until he found that one fly had white eyes instead of the usual red ones. He then mated this fly with a red-eyed fly to discover that red eyes were dominant traits and white eyes were recessive. Afterwards, Morgan continued experimenting with mating and learned that recessive traits are linked to sex. This led to use of genetic tables for determining which traits will be seen in certain offspring with term XX meaning female and XY meaning male. Morgan learned that a male can only inherit a specific recessive trait from its mother and a female can only inherit a specific recessive trait if both the mother and the father show that specific trait. He proposed that each chromosome contained genes, with different genes having specific locations on certain chromosomes.
Thomas Morgan’s discoveries allowed people to learn more and to dive deeper into studying of genetic traits and how exactly specific traits can be passed from one generation to another. The Morgan is now a unit of measurement of distances along chromosomes of humans, mice, and flies. In addition to his work on genetics, Morgan also made contributions to experimental embryology and to regeneration. He showed that gravity was not important in the development of the egg and that regeneration is not an adaption. Morgan was made a Foreign
Member of the Royal Society of London in 1919, awarded the Darwin Medal in 1924, and the
Copley Medal in 1939. He was also award the Nobel Prize for his work on chromosomes in heredity. Morgan passed away in 1945.

Reflection
This assignment has allowed me to learn something important that I would have never bothered learning about on my own. I have learned many different things about genetics that I never knew before and some things that I managed to recall while researching about my topic and writing about it. My research has brought up many familiar things that I learned recently in biology class and other things that I learned about biology a long time ago. This assignment connects well with my English class because the requirement in length is similar to most of my assignments in my English class. It helped me progress in my writing to make me more confident about it even if only a little. To that regard, this assignment connects with most of my previous general education courses. The assignments are quite similar, so this one is nothing new. The report changed nothing about my perceptions of this subject because had a no considerable perceptions of it to begin with anyway. I thought of it as just another assignment, though researching Thomas Hunt Morgan wasn’t entirely easy. I did struggle to find good information for a while. Overall, this assignment was fine and I did not mind working on it.

References
"Thomas H. Morgan - Biography". Nobelprize.org. 15 Mar 2012 http://www.nobelprize.org/nobel_prizes/medicine/laureates/1933/morgan-bio.html
Kandel, Eric. 15 Mar 2012. “Thomas Hunt Morgan at Columbia University.” http://www.columbia.edu/cu/alumni/Magazine/Morgan/morgan.html
Allen, Garland. 15 Mar 2012. “Thomas Hunt Morgan.” http://www.britannica.com/EBchecked/topic/392256/Thomas-Hunt-Morgan
Miko, Llona. 2008. “Thomas Hunt Morgan and Sex Linkage.” http://www.nature.com/scitable/topicpage/thomas-hunt-morgan-and-sex-linkage-452