What Darwin Never Knew Blog post
Written by Raihan Chung
Introduction:
Charles Darwin was a naturalist that was born in the United Kingdom in the year of 1809. He always had a love for the natural world, and barely focused on other subjects. His father, who was a successful doctor, wanted young Charles to enroll in medical school, but Charles had other plans. When Charles was 22 years old, he was offered a spot on the HMS Beagle, a ship that was going to the Galapagos islands to do research, as the ships naturalist. They sailed around the majority of South America, and Darwin was amazed by the vast variety of life. When he arrived at the Galapagos Islands, he made his first discovery that would change the ideology of evolution forever. He noticed that the wide range of species that lived on the islands had specific traits that arose from which island they originated from. Darwin thought that this was due to the different habitats and food found on each island, and came the conclusion that these species transformed over time due to specific survival traits and climate.
How did the discovery of DNA prove that Darwin’s theory of evolution was correct?
DNA was one of the most ground-breaking genetic discoveries to this date. According to sciencehistory.org, the concept that all animals consist of DNA and genes, each with different bonds and mixes, arose around the year of 1953, when scientists James Watson and Francis Crick developed the idea of a double helix deoxyribonucleic acid. They discovered it was what held the hereditary traits and created proteins that each had different uses. This discovery proved that Darwins theory of evolution was correct because DNA shows how related some species of animals are, and how DNA hold all ancestral traits. It also shows how all species have one common ancestor, based on the traits being handed down over generations. DNA shows the more closely related species are to each other, the more similar the strands of DNA are, showing they have a common ancestor. In “What Darwin Never Knew”, a program from NOVA flims, Darwins theory of evolution shows how organisms adapt and acquire traits that help them survive based on their DNA and ancestors. Darwin called the idea that all organisms share a common ancestor the “principle of common descent”, meaning each organism has some sort of common DNA being passed down. In most cases, a certain species and their common ancestor share traits that have helped them survive and exist while also removing traits over generations that did not help them survive and flourish.
How did the discovery of DNA change how we view the concept of evolution today?
According to independent.co, after the discovery of the double helix DNA, scientists and naturalists all over the world took a deeper dive into the vast seas of evolution. It is now possible for scientists to identify individual genes of an organism, as well as the different base pairings. Using this knowledge, they can compare different species to one another and see how similar or different they are. DNA can show how humans lived in the past, and when they met up with different cultures, which is the main reason we have so many mixed backgrounds. Evolution shows the way organisms grow and adapt to their environment, and DNA can show us why they adapted the way they did, as well as how they chose which traits to keep and discard. For example, in the video “What Darwin Never Knew”, the tortoises that lived on the Galapagos Islands each had a unique trait on their shell. This trait showed Darwin which island the tortoises were from, and why they had developed certain traits like thicker shells, smaller legs, or large, domed shells. Each one of these tortoises had these adaptations due to the food source, environment, and predators that lived on the island they did. The discovery changed how we view evolution today because it paved the way for scientists to take a closer look at the genes and base pairings within different organisms to see concrete evidence on how they are related to each other.
– the different tortoise types on the Galapagos islands
How does the discovery of DNA change the way we view evolution going into the future?
DNA was the ultimate discovery as it can diagnose humans and other organisms on specific diseases, or traits that may be passed down from their ancestors. We can use this data to predict different adaptations that future generations will have based on patterns in the DNA and organism ancestors. With more advanced technology and research being created and found, DNA can be used to find out what species may look like in the future. We could also look further back along the timeline to see if the organisms’ ancestors grew and evolved from even older ancestors, which will broaden our understanding on how life came to be and why it is so diverse and unique to specific environments. For example, in “What Darwin Never Knew”, program by NOVA flims, the finches, which is a type of bird, on the Galapagos islands each had different beak sizes and shapes, to help to survive on its island. Darwin noticed that certain beak shapes were less common then others, which meant that shape and size was not a “desirable” trait as the finches were dying off. Darwin came to conclusion that all finches had grown and acquired the beak sizes based on the island, and their common ancestor. All the finches were unique in their own way, whether it was different feather patterns, longer or stronger wings, which is evidence that even though they had a common ancestor, over the years, their DNA has changed to develop different adaptations which will help them be better suited for their environment. DNA will help the future to predict different adaptations that humans will undergo and help discover diseases that could be possible in the future. This is know DNA can help in the future.
– Tree of life showing all life forms from a common ancestor
Sources:
https://www.sciencedirect.com/science/article/pii/B9780128175545000058
https://www.independent.co.uk/news/science/23-ways-that-dna-changed-the-world-5352712.html