What Darwin Never Knew

Charles Darwin “The father of evolution” is famous for his theory of evolution. Darwin came up with this theory by observing finches and tortoises on the Galapagos islands. By studying the finches and tortoises, Darwin realized that species change. He theorized that organisms with traits that helped them live in their environment would live longer and reproduce, passing the advantageous trait down to their offspring. He called this survival of the fittest.

However, Darwin didn’t know the mechanism for how these traits were passed on. Genetics and DNA weren’t discovered until 1953, 71 years after Darwin died. DNA proved that Darwin’s theory was correct that species change over time because DNA doesn’t stay the same, it mutates. With the discovery of mutation, we know that genes are responsible for evolutionary change. Without mutation, everything would stay the same from generation to generation, which we know is not the case.

The discovery of DNA also changed how we view evolution. Before the discovery of DNA, we knew roughly how evolution worked, but now we know that mutation in genetic code is what leads to different traits in species. For example, a mutation in the human jaw muscle is what allows humans to have bigger brains, a key difference between humans and chimps. We also now know that small differences in our genetic code make a huge difference, with there being only a 1 percent difference in DNA between humans and chimps. We also know that a huge part of evolution has to do with switches, which control what genes are “turned on” and what genes are “turned off”.

Lastly, the discovery of DNA changes how we research evolution in the future. To identify differences in species, we know to look for mutations in genes, then compare that gene to other organisms to see what differences the mutation makes. We also know that evolution doesn’t just happen in DNA that codes for a protein, but also in the switches that control those genes. Instead of wondering if there is a mutation in the gene that makes a protein, we can look for a mutation in the switch that controls that gene.

Overall, the discovery of DNA not only proved that Darwin’s theory was correct but opened several new ways to look at and research evolution. Instead of making hypotheses based on observable traits, we can now look at the genetic code of organisms. Not only that, we know where specifically we can look for mutations, whether that be in switches or the gene itself.

Sources:

Than, Ker. “What Is Darwin’s Theory of Evolution?” Livescience.Com, 17 May 2021, www.livescience.com/474-controversy-evolution-works.html.

Ramanujan, Krishna. “Genetic Switches Play Big Role in Human Evolution.” Cornell Chronicle, 13 June 2013, news.cornell.edu/stories/2013/06/genetic-switches-play-big-role-human-evolution.

“NOVA.” What Darwin Never Knew – NOVA PBS Documentary, 27 Dec. 2009, www.pbs.org/wgbh/nova/video/what-darwin-never-knew.