How did the discovery of DNA prove that Darwin’s theory of evolution was correct and how does it change the way we view evolution today and into the future?

During the 1800’s scientists started to believe that species were changing and modern organisms came from ancient organisms but it wasn’t until Charles Darwin proposed a revoluntionary theory of evolution by natural selection. He suggested that organisms change in either physical, heritable or behavioural traits. He also proposed that organisms who do such develop higher fitness, meaning the changes in physical traits and behaviours allowed them to become more adapted in their environment, thus, increasing the chances of survival and reproduction rate. Darwin’s theory also stated that populations increase at a geometric rate meaning they multiply rapidly, resulting in a struggle for existence. There is also variation in each species, and the more favourable ones get passed on to the offspring. Darwin theory was high in accuaracy but lacked evidence. Then almost 100 years later, after many try’s to prove his theory, DNA properties were discovered. This allowied scientists to expand on Darwin’s theory and justify it. In the movie “What Darwin Never Knew” we explored many examples of how the discovery of DNA proved Darwin’s theory and changed how we view evolution today and into the future. DNA and genes is what makes us all so different on earth. Every organism has a different set of genes, this is caused by mutations. For example mutation occurs when one of the nitrogenous bases accidentally gets replaced by another which can either be fatal or helpful in some cases.

Images showing evolution:

How did the discovery of DNA help prove Darwin’s theory? And how does it change the way we see evolution into the future? 

Let us look at the genetic comparison between chimpanzees and humans, tikaalik, Hox genes and embryology. Darwin came up with a theory that humans descendened from monkeys, he was mocked at the time for coming up with such a thought. But after the discovery of DNA, scientists found that there is only a 1% difference in the DNA of a chimpanzee and a human. The difference is in some switches in genes that involve the human brain. This shows how just a slight change in DNA can cause such a massive effect. Tikaalik shows transition from fish to amphibians. This shows that since much varied vertebrates did once exist, but this animal evolved on land instead. Another massive discovery was of the “switches” that turn specific genes on and off. An example would be Hox genes that are a group of genes that control the body plan of embryos. They were found in many complex animals going back to 600 million year worms to modern day humans. This idea of switches is proven though embryology; the study of organisms in their early stages that change over the course of time. Switches explain how one creature can become more like another. An excellent example would be the Galapagos finches, and how the same genes are responsible for the different types of beaks. The only different is which gene is switched on or off. “Darwin’s finches speciated into 14 different species in under 2 million years and they are the best-known example of vertbrate evolution and the most recent example of adaptive radiation.” All these examples can be used to verify Charles Darwin’s theory of evolution and his idea of the tree of life. The discovery DNA established a solid foundation for evolution and caused researchers to start focusing more on genetics. It has answered some very complex questions we have such as where we came from, what makes us up and what sepereates us from all other creation. There is still much to be discovered out there, but DNA was the first step in the process.

Sources:

http://www2.nau.edu/lrm22/lessons/bird_lab/bird_lab.html

Documentary: What Darwin Never Knew. Produced by Matthew Barrett. 2011. DVD -Nova

https://earthwatch.org/Scientific-Research/Our-Scientists/Sonia-Kleindorfer