Darwin’s Theory

Charlize Jacobsen

Mireau

Biology

March 4, 2023

Darwin’s Theory

Darwin’s theory of evolution was called On the Origin of Species that was published in 1859. “…The best idea anyone has ever had.” (0.24) The theory was that species can change over time and adapted to their environment, that each species come from pre-existing species and that all species come from a common ancestor. Darwin’s theory was the start of evolution research and was the foundation for scientific growth. DNA was discovered long after Darwin passed away in 1953. How DNA proves that Darwin’s theory of evolution was correct is because he knew about the changes in species and why they would change to be the fittest and for survival, but he could not pinpoint why. Once scientists were able to look deeper into DNA and read the coding this proved that Darwin was correct. Darwin was correct because a piece of DNA called a switch was able to turn off or on. This then showed visible differences in the species. Three theories that prove Darwin was correct are the Galapagos finches, the chimps compared to humans and Tiktaalik fossil.

 

The Galapagos finches were evidence that Darwin’s theory of evolution was correct. The Galapagos finches had changed over time and adapted to their surroundings. The unique aspect about them is that throughout the island the same type of finch had different beaks. When Darwin visited the Galapagos, he did not realize at first that all these finches were the same type until he got back home. This was one of the species that took off is theory. When scientists later visited the Galapagos, they went throughout the island and studied the embryos of the finches. Then they would use a light to shine through the egg just before they would hatch and see that the different beaks started when they’re in eggs and not after they were born. This spark the idea that the changes were because of DNA. After, discovering it is because of DNA they had to look through different codes and see the differences between each finch that was found on different parts of the island. Why all these finches had different beaks were because they used them as tools. This was all due to natural selection.

 

The chimpanzees compared to humans is proof of Darwin’s theory because species come from pre-existing species. The difference of genes between chimpanzees and humans are 1%. How we are so different, is the mutation humans had over time. The characteristics that we developed to make us the fittest. As humans have smaller jaw bones to make room for a bigger brain. Whereas chimps have very large jaws that they use for eating hard veggies but that large jawbone means that the brain cannot grow larger. Another, that makes us different is our thumbs and hands. The main difference between humans and chimps is two gene letters that are missing in chimps. This is called a DNA switch same thing that happened with the Galapagos finches

Lastly, is the Tiktaalik fossil this fossil proves that all species come from a common ancestor. The Tiktaalik is a flat head species that almost resembles an alligator. When scientists first found this fossil, they noticed that it had a tail, but it had arms at the front to lift its head up onto land to flee predators. This showed that this species was prey and needed to leave the water to survive. Scientists then looked at whales and snakes that still have hip bones passed down from their ancestors. This proves that species that we see in our world today have evolved to be the fittest. Many scientists believe that every species came from a tree of ancestors and that humans can be connected to a fish. Tiktaalik arms/fins had bone stretcher of every four limed animal. So, Tiktaalik could have been one of our first ancestors.

 

How Darwin’s theory changes the way we view evolution today and the future is because we know so much more about how DNA is involved in evolution. If we were able to look into the future humans can evolve to look different then we do today, to be the fittest humans they can be in their environment. How it helps us today is to best understand why species of the same type change because of the switches in DNA. Proving that Darwin’s theory was correct with DNA changed evaluation. Now we can predict changes in the future or understand why changes happen today.

Works Cited

Public Broadcasting Service. (2009). What Darwin Never Knew. PBS. Retrieved March 5, 2023, from https://www.pbs.org/wgbh/nova/evolution/darwin-never-knew.html.

Admin. (2022, August 1). Darwin’s contribution-The theory of evolution & natural selection. BYJUS. Retrieved March 5, 2023, from https://byjus.com/biology/darwins-contribution-theory-evolution/