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? 

“Darwinism is a theory of biological evolution developed by the English naturalist Charles Darwin (1809–1882) and others, stating that all species of organisms arise and develop through the natural selection of small, inherited variations that increase the individual’s ability to compete, survive, and reproduce.”- Wikipedia. Charles Darwin is the well-known developer of the ideas of natural selection- the way that life-forms change. He also thought of the idea of “fitness” when regarding organisms, noting that most have physical traits and behaviours that allow them to survive and reproduce in their environment.

In 1859 Darwin published The Origin of Species, which has since acted as the basis for evolution and DNA discovery and development. Darwin hypothesized that species changed, and said change in nature started with variation. He believed that over many generations, tiny variations allow the fit to get fitter and the unfit to vanish. He described this process as evolution by natural selection. Darwin, in The Origin of Species, also stated that modern organisms have been produced through evolution from pre-existing organisms: that each species has descended from other species. And if you look back far enough you will see that all species have shared a common ancestor. Darwin called this principle “common descent”, believing that all organisms were related to each other- the first time someone had hypothesised such an idea. An incredible scientist, he knew his ideas were strong but had no true way to prove them. Fast-forward to the present-day, the discovery of DNA has been able to concur with Darwin’s theories. DNA now tells us that we truly are simply descendants of a common ancestor, like any other organism, and we share 99% of our DNA with apes. However, if our DNA is so similar, how are we so different from apes? How did the evolution we see, actually happen? Dr. Hansell Stedman (University of Pennsylvania School of Medicine), was able to discover the answer to said questions while searching for a cure for muscular dystrophy. He discovered, when comparing DNA of humans to apes, that one of the only things that set us apart in our DNA was a mutation coding for the jaw muscle. The mutation meant that humans didn’t need as much muscle mass in order to chew- their jaw muscles didn’t need to grow as large as apes’ do. The idea that the jaw muscle didn’t need to grow as much, meant that in a human skull, there was more room for the brain to grow: giving us the brain complexity and size that sets us apart from most organisms (including apes). This goes to show that evolution occurs from mutations in DNA. DNA has been able to prove Darwin’s theories: it proves that we are all from a common ancestor (which can also be shown through embryo structure and development) and it proves that change also starts with variation- and mutations! Tiktaalik is a good example of how DNA proves Darwin’s theories. Tiktaalik would have been one of the first organisms that mutated to have fins fleshy enough to support their weight. A prey in predator-filled waters, Tiktaalik emerged onto land in order to protect itself. It was only able to do so because of the mutation in its’ fins. It would have gone on and ended up reproducing, passing on the mutation to its’ offspring, creating a slightly different species than before. What may have been a small mutation changed Tiktaalik and it’s offspring into a completely different organism, one of the beginnings of land-bound animals, including humans. DNA has been able to show us that Tiktaalik, as well as others, would have continued to reproduce, and mutations would have continued to occur (as well as natural selection) for the entirety of the 365 million years that have passed since then until we get to where we are today. Until we get the organisms that we have today.

The work of Charles Darwin changed the way people viewed evolution and existence forever. For the first time, he hypothesized that all life was related. He believed that we all came from the same thing, the same common ancestor. Before Darwin, most people believed that everything was created at once, that God himself had made humans the way they were, in order to be better than the other organisms.  Darwin and the discoveries made off of his work have changed people’s beliefs and thoughts towards evolution. Without Darwin, and the discovery of DNA, we would still believe that we simply popped into existence one day, unknowing that we all came from the same ancestor millions of years ago. DNA has also been able to change the way we view medicine today. When Dr. Hansell Stedman discovered the mutation in humans that sets our minds apart from those of apes, he was searching for a cure for muscular dystrophy. Without the discovery of DNA, the research done on microcephaly wouldn’t have been possible either- scientists were searching strands of DNA to find which gene or genes were responsible for microcephaly, in order to inform families whether or not their child would have the mutation as well. Due to the work of Charles Darwin, and the discoveries made in DNA, life today is viewed as ever-changing. Evolution is now known as responsible for the variation in life on earth, and we can now study how all organisms change through time, including ourselves.

While there may have been enormous discoveries in the fields of evolution and DNA, there is still so much left to be discovered. The “switches” in DNA are only now being explored, previously unknown and unrecognized as the controls of DNA. We know now that switches are responsible for the paint-spot genes on fruit flies that give them their black spots, whether the switch is on or not dictating whether or not they get black spots. While “switch” discoveries have certainly been made, there is equally as certainly many more discoveries to come with the switches, and how they related to evolution and DNA. Overall, there is still so much unknown about DNA and evolution that the perspective is bound to change within both the next couple years and the next couple millions of years. New species could develop, and old ones can disappear- mayhap even humans as we know them will have developed until they would be unrecognizable to us today. The discovery of both evolution and DNA may not be finished, but it has clearly laid the path for the future. Without Darwin, it’s possible DNA as we know it would never have been explored or discovered, and the natural and scientific world as we know it would not exist to us. Hopefully DNA will lead to the discovery or evolution away from certain illnesses, like cancers, however, there’s currently no true way to know right now. All we can do is wait until more discoveries towards DNA and evolution are made until the evolved future appears. But we do know this: Charles Darwin has changed the basic view of human and natural life, changed the thought process towards DNA and evolution for forever, and even in the future he will probably still be known as the “father of evolution”.

 

Works Cited: 

Tiktaalik Image:

News Staff. “New Fossils of Tiktaalik Roseae Amaze Scientists.” Sci News, Sci News, 14 Jan. 2014, www.sci-news.com/paleontology/science-new-fossils-tiktaalik-roseae-01686.html

Dr. Hansell Stedman Image:

“Hansell Stedman, MD.” DuchenneXchange, www.duchennexchange.org/people/hansell-stedman-md/

Microcephaly Image:

“Facts about Microcephaly | CDC.” Centers for Disease Control and Prevention, Centers for Disease Control and Prevention, www.cdc.gov/ncbddd/birthdefects/microcephaly.html

Spotted Wing Drosophila (fruit fly) Image:

Colorado State University Extension. “Spotted Wing Drosophila.” Colorado State University Extension, wci.colostate.edu/shtml/SpottedWingDrosophila.shtml.