How DNA Proved Darwin’s Theory to be True
Charles Darwin travelled to The Galapagos Islands and saw organisms that could only be found on the islands. When he discovered that tortoises from different islands had a different kind of shell, and that finches from different islands had a different type of beak depending on what type of food they ate, he began to realize that for some reason, species change. Charles Darwin came up with his theory that species change, before DNA was discovered by James Watson and Francis Crick, with the help of Rosalind Franklin in 1953. Charles Darwin knew that his theory was not yet complete and he understood he was missing crucial information he needed to fully understand what was causing species to change. Once DNA was discovered it proved that Darwins theory was indeed true.
Darwin theorized that the reason species changed, was because of natural selection. Darwin thought that the weakest organisms would not survive or reproduce therefore, the future generations would be the organisms with more favourable traits to fit their environment. What Darwin didn’t understand was why some organisms varied with slight differences. Darwin was not aware of DNA. DNA is what contains all of an organisms genetic information and inside DNA there are genes. Sometimes DNA can have mutations. DNA contains switches that turn on and off genes and can create mutations and variation. When variation occurs, Darwins theory proves true. In the video “What Darwin Never Knew”, they study an example of adaptations in mice that live in the desert, but there are many different examples of natural selection. Another example of this is giraffes. Because of variation in the genes, some giraffes naturally had long necks and some had shorter necks. Because giraffes get their food from tall trees, the ones with long necks had an advantage and were most fit for their environment. The giraffes who had a disadvantage because of their short necks were not likely to survive or reproduce. This means the tall necked giraffes could reproduce which caused the future generations of giraffes to have tall necks, because they inherit traits from their parent giraffes. This is how DNA confirmed and completed Darwins theory.
How the Discovery of DNA Changes the way we View Evolution Today
The discovery of DNA effects how we view evolution today in many ways. DNA lets us know why things are the way they are. DNA proves that evolution is not gradual but instead it involves sudden bursts of rapid adaptions. Rapid adaptation can occur because of switches that can turn genes on and off. This knowledge helps us to better understand evolution. An example of DNA helping us to understand why things are the way they are, is the Tiktaalik fish. In the video “What Darwin Never Knew”, it mentions the Tiktaalik and how they studied it. When Tiktaalik was discovered, scientists were able to be specific and know exactly how and when some animals went from the ocean to the land. Scientist compared Tiktaalik’s DNA with another fish’s DNA that was Tiktaalik’s descendent. If DNA was never discovered, we would never know how animals moved from the ocean to land. It is important to understand DNA because it can tell us the important details about how organisms are made.
How the Discovery of DNA will Change the Future
In the future, I think DNA will have a big impact in preventing health issues such as diseases and disabilities. Because DNA shows how something happens, doctors may be able to find a way to prevent the issues from happening in the future offspring. In the video “What Darwin Never Knew”, it mentions microcephaly and why it happens. Without the discovery of DNA we would not be able to understand why some people have microcephaly. In the video “What Darwin Never Knew” they also mention that chimps and humans have 99% of the same DNA. Most of the differences are in switches that turn genes on and off. In the future I think we will be able to have a deeper understanding of changes in the switches of genes in species and we will be able study their adaptations further.
Sources
What Darwin Never Knew Video Documentary
https://www.pbslearningmedia.org/resource/midlit10.sci.spltransition/tiktaalik-a-fish-out-of-water/
https://www.pbs.org/wgbh/nova/article/dna-human-evolution/
http://turtlesinturmoil.blogspot.com/2015/04/evolution-in-galapagos-tortoise-vs.html
https://nebula.org/blog/dna-deoxyribonucleic-acid/
http://www.vce.bioninja.com.au/aos-4-change-over-time/evolution/evolutionary-theories.html