My AP Biology Thoughts

Episode #3

Welcome to My AP Biology Thoughts podcast, my name is Nidhi and I am your host for episode 3 called Unit 7 Evolution: Darwin’s Early Influences. Today we will be discussing what led Darwin to researching and creating his theory of evolution.

Segment 1: Introduction to Darwin’s Early Influencers

• Our current belief of evolution is that species change in characteristics over several generations and this can be caused by natural selection. These characteristics are the expressions of genes that are passed on from parent to offspring during reproduction. Natural selection is the process where organisms better adapted to their environment tend to survive and produce more offspring. As a result, the traits that help the organisms survive will be passed down and the gene pool will shift causing evolution. 
• Darwin’s theory of evolution stemmed from the idea of natural selection. Darwin’s early life can be broken up into 2 parts. The first was his education and influence of his father and the 2nd was his voyage aboard the HMS Beagle. 

Segment 2: More About Darwin’s Influencers

• One of Darwin’s early influences was his father. His father, Robert Waring Darwin’, had made Medical observations that Darwin would read to learn about human psychology. He was sent by his father to study medicine at Edinburgh University when he was 16. He described this experience as formative. And He believed he received the best science education he could have at a British university. Edinberg was where he was first exposed to the belief that animals share all of humans mental capabilities. This is an early belief that evolved into his research of evolution and the connection between species. He began to research this and was accompanied by his mentor Robert Edmond Grant when he learned about sponges in an effort to unlock the mysteries surrounding the origin of more complex creatures. 
• Darwin formulated his theory of evolution in private from 1837-1839 after returning from a voyage around the word aboard the HMS Beagle. On his journey aboard, he spent 5 years along the coast of South America exploring the continent and the Galapagos Islands. He filled many notebooks with observations on animals, plants, and geology and collected many specimens he sent home to study. Later in his life, he called the Beagle voyage the most important event in his life, saying it determined his whole career. Before the voyage he was planning a career as a clergyman but when he returned he was well known in London for the specimens had sent home. His beagle voyage is credited for providing him with the seeds for his evolution theory that he would spend the rest of his life working on. 
• Darwin was also influenced by 3 earlier thinkers. The first is Jean Lamarck who was one of the first scientists to propose that species change over time. However, he was wrong about how species change with his belief that traits an organism develops during its own lifetime can be passed onto offspring. Additionally, Charles Lyell’s book Principles of Geology was taken by Darwin with him on the Beagle. In the book, Lyell claims that the Earth is much older than people believed. Lastly, Thomas Malthus wrote an essay titled On population. In this he argues the population is kept in check by killing off the weakest members when a population gets too large and there aren't enough resources. The ideas of these 3 thinkers greatly influenced Darwin when he was forming his theory of evolution. 

Segment 3: Connection to the Course

• Darwin’s theory of evolution by natural selection became the foundation of modern evolutionary studies. He is best known for his published book On the Origin of Species. His research of the Galapagos Finches is often cited in class as evidence for evolution by natural selection. He had observed while on his voyage that beak shape varies among finch species. This caused him to theorize that the beak of an ancestral species had adapted over time to equip the finches to acquire different food sources. 

Thank you for listening to this episode of My AP Biology Thoughts. For more student-ran podcasts, make sure that you visit www.hvspn.com. Thanks for listening!

Music Credits:

"Ice Flow" Kevin MacLeod (incompetech.com)

Licensed under Creative Commons: By Attribution 4.0 License

http://creativecommons.org/licenses/by/4.0/

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