How did the discovery of DNA prove that Darwin’s theory of evolution was correct?
Charles Darwin's theory of evolution proposed that "species can change over time, that new species come from pre-existing species, and that all species share a common ancestor." The discovery of DNA is used as evidence of this theory because it proves that all species have a common ancestor. For example, in reference to the video in class, it is mentioned that humans and chimps only have a one percent difference in their DNA's. Therefore, this must mean we share a common ancestor since humans and chimps look nothing alike and are considered different species. Furthermore, DNA has an affect on how an organism looks and behaves and as we learned in the previous unit, DNA synthesis is not flawless and offspring may be created with a combination of DNA from two individuals. So, mutations may occur which cause changes to the organism and fitness for survival (for better OR for worse). Due to these mutations, those with fitter attributes will survive to reproduce and pass down their genetics. Another example according to the video is that finches from different islands of the Galapagos have different beaks depending their island even though they are the same species. Additionally, even different species have similar traits like the archaeopteryx fossil having features of both birds and dinosaurs.
How does it change the way we view evolution today?
Before scientists discovered DNA, they could only discover the evolutionary tree of life using a comparison of bodies and cells of different species. However, now it is not only possible for them to identify the genes but also they can identify the individual bases. Not to mention, they are able to compare genetic codes down to the deepest branches of life from billions of years ago. As mentioned in the video, without mutation everything would stay the same but since that is not the case we are now able to find the specific genes responsible for evolutionary change. The closer the relation in species, the more DNA will overlap with one another. However, all species have some sort of overlapping and like that scientists can discover how near or distantly each species has evolved from the other and their relations.
…and into the future?
What the future holds will always be unknown. Scientists are discovering new things everyday so it is more than likely that the beings of the future will look back and think of us as fools for not making certain connections earlier. Who knows, perhaps humans will evolve into another species and so will animals, creating another way of living amongst each other. It is certain that the discovery of DNA is only another stepping stone to endless possibilities.
Sources
https://youtu.be/ov00SrBwjKQ
DNA, the Language of Evolution: Francis Crick & James Watson
https://www.thoughtco.com/dna-and-evolution-1224567
