The current understanding of the way traits are inherited from generation to generation is based on the principles put forward by a 19th-century biologist, geneticist, and mathematician Gregor Mendel. These principles were discovered by Mendel upon studying the pea plant and it took him eight years of experimentation and persistence to continue with it1. Mendel’s courage to experiment resulted in his great discoveries and inspired all other generations of geneticists to be brave enough to search for unexpected solutions.
A person that is not as often talked about as Mendel, but that is deemed one of the most prominent geneticists in history is Thomas H. Morgan. Morgan was breeding fruit flies when he and his team decided to incorporate the Mendelian approach with the field’s other significant line of research, the chromosome theory of inheritance. Their notion that hereditary material is situated within the chromosomes produced a physical basis for said material. An interesting fact about Morgan was that he was trained as an embryologist despite being a fruit fly genetics father. He once spoke about the complaints of the embryologist society about genetics not explaining the phenomenon of a single set of genes being able to produce many tissue types2. Society believed that genes were to be controlled by agents outside the nucleus, that is, in the cytoplasm; Morgan wrote that the cytoplasm might be genetically ignored.
Eventually, a solution to the problem of development not referring to the cytoplasm was reached. The person behind the solution was Barbara McClintock, already one of the most admired geneticists at the time. She argued that the movable elements were small units of heterochromatin that pranced around the chromosomes when the plant grew and developed3. The landing of an element near a gene or in it led to a local position effect by suppressing the gene. This is how came the explanation of mutable genes; their dynamic expression was not the result of the internal chemical changes but the transposable elements’ reversible modulation.
In this regard, it is evident that experimentation plays a central part in the history of inheritance and genetics. While it is correct to say that scientists’ job is to explain and understand, it is impossible to imagine a scientist who does not research and investigate. After all, some of the most important aspects of science can only be comprehended with relation to such concepts as investigation and exploration, and not understanding knowledge or truth.
Bibliography
Comfort, Nathaniel C. “The Real Point is Control”: The Reception of Barbara McClintock’s Controlling Elements.” Journal of the History of Biology 32, no.1 (1999): 133-162.
Gliboff, Sander. “Gregor Mendel and the Laws of Evolution.” History of Science 37, no.2 (1999): 217-235.
McClintock, Barbara. “The Significance of Responses of the Genome to Challenge,” Science 226, no.4676 (1984): 797.
McClintock, Barbara. “The Significance of Responses of the Genome to Challenge.” Science 226, no.4676 (1984): 792-801.
Footnotes
- Sander Gliboff, “Gregor Mendel and the Laws of Evolution,” History of Science 37, no.2 (1999): 220.
- Nathaniel C. Comfort, “The Real Point is Control”: The Reception of Barbara McClintock’s Controlling Elements,” Journal of the History of Biology 32, no.1 (1999): 139.
- Barbara McClintock, “The Significance of Responses of the Genome to Challenge,” Science 226, no.4676 (1984): 797.