Introduction
One of the most important, if not the most important concepts in modern biology is evolution. The idea that organisms change with time and are all related back to a common ancestor was revolutionary, and important for understanding pretty much every aspect of biology. The history of the theory of evolution was long and complicated, and evolutionary thought had been a thing for hundreds of years, but perhaps the most revolutionary thinker was Charles Darwin, who was born on this day, February 12th, 215 years ago.
Darwin’s Early Life
Charles Robert Darwin was born in Shrewsbury England on February 12th, 1809. He was born into a wealthy family with 5 siblings, with his father and mother, though his mother died when he was young. On his fathers side, there was a history of scientists, with his father, Dr. R. W. Darwin being a medical doctor, and his grandfather, Erasmus Darwin being a well known botanist.
His father hoped his son would go down the path of medicine as well, but Darwin was more interested in natural history. After graduating from Christ’s College in 1831 with a bachelor degree of arts, a botany professor, John Stevens Henslow, recommended Darwin take a naturalist’s position on the HMS Beagle, a trip that would not only change his life, but would change the history of science as a whole.
The ship, captained by Robert Fitzroy, embarked on its 5 year journey in December of 1831 when Darwin was 22 years old. His role on the boat was to study the discoveries made on the journey, but also to provide companionship to the captain.
In total, he spent about 1,200 days on land during the voyage, where he would study many different animals, plants, and fossils. Most famously during the journey, the Beagle spent 5 weeks on the Galapagos islands. It was on these islands where his observations would form his famous theory of evolution by natural selection.
On the Galapagos islands, he studied geology and wildlife. Most famously, he studied the birds of the islands. Though commonly called Darwin’s finches, these birds weren’t actually finches, and were likely more closely related to blackbirds or mockingbirds. Regardless, the observations Darwin made about these birds were crucial for the development of the theory of natural selection.
These birds proved to be an incredible example of adaptive radiation, speciation, and natural selection.
Darwin’s Research and Work
The environmental occurrences on the islands led to a great variation in the birds, such as variation in beak size, body size, plumage, etc.., as they adapted to the different environments of the different islands.
The beaks were some of the most prominent examples, as each bird species adapted to different food sources. The geographic isolation across the different islands led to allopatric speciation, as gene flow between the different populations was stunted.
It wasn’t completely stunted however, as genetic research shows that there was interspecific gene flow across the species, resulting in hybridization, making this a good example of the arbitrary nature of ‘species’.
Genetic analysis also showed the different genes that affected the adaptation observed in the finches. The ALX1 and HMGA2 genes for example have been shown to affect the shape of the beaks across the different species. His observations on the Galapagos, along with his expedition of the Beagle as a whole, inspired Darwin to write On the Origin of Species, one of the most significant works of scientific literature. This book would be published in 1859.
In this book, Darwin proposed his theory of evolution by natural selection, along with the theory of common descent, two crucial ideas in modern biology. This book sparked many, often religious debates, but was more widely accepted due to the evidence and arguments he provided.
Darwin would go on later to publish several other books, including The Descent of Man, and Selection in Relation of Sex. He covers multiple topics in this book, including sexual selection, but more importantly, he addresses the topic of human evolution.
He talks about embryology in the first chapter as a way to study human evolution. In a time without hominin fossils and genetics, he had to pull from what he had.
He made several predictions that would later be proven, such as the idea that humans evolved in Africa, but also made several problematic claims about race and sex, proposing that human social organization follows a straight path from savagery to more advanced cultures.
However, this doesn’t mean that all of Darwin’s views on these topics were wrong.
Most famously, Darwin strongly criticized and disliked slavery, and strongly supported abolition. Darwin was a product of his time, just like everyone is, so it’s understandable that he had views that today we view as controversial today, because they were normal back then. That is how society functions. We cannot critique his scientific theories purely on the basis of these specific views. Rather, we should view them with a critical and most importantly scientific lens, and understand the many things he got wrong and right about evolution.
Conclusion
Darwin would die April 19th, 1882, at the age of 73, in Kent England. He lived a long and successful life, had many kids, and many scientific achievements. His ideas were revolutionary, and much of them we know today were spot on, but not all. He got things right, he got things wrong, but what he got right was incredibly important for our modern understanding of biology.
It is important to note that scientists do not praise Darwin. They did not and do not follow his every word and idea. A good scientist should recognize what he got wrong and right, and understand the significance of his ideas on evolution and the history of life on this planet. Darwin was a normal man, but a man who had many ideas that have been shown again and again to this day to be correct. Happy Darwin Day!
Sources
- “Charles Darwin”. Biography, 03-29-21. https://www.biography.com/scientists/charles-darwin
- Mcnamara, Robert. “Biography of Charles Darwin, Originator of the Theory of Evolution”. ThoughtCo, 07-29-21. https://www.thoughtco.com/who-is-charles-darwin-1224477
- Lotzof, Kerry. “Charles Darwin: History’s most famous biologist”. Natural History Museum (ND). https://www.nhm.ac.uk/discover/charles-darwin-most-famous-biologist.html
- Scoville, Heather. “Charles Darwin’s Finches and the Theory of Evolution”. ThoughtCo, 06-26-19. https://www.thoughtco.com/charles-darwins-finches-1224472
- “Adaptive Evolution in Darwin’s Finches”. Harvard University (ND). https://scholar.harvard.edu/sangeet/adaptive-evolution-darwins-finches
- “On the Origin of Species”. Harvey Cushing/John Hay Whitney Medical Library (ND). https://library.medicine.yale.edu/about/adopt/darwin
- “The Reception of Darwin’s On the Origin of Species”. The Humanist.com, 01-29-15.
- Pyne, Lydia. “Charles Darwin’s Descent of Man, 150 Years Later”. JSTOR Daily, 02-20-21. https://daily.jstor.org/charles-darwins-descent-of-man-150-years-later/
- “Darwin and slavery”. Darwin Correspondence Project (ND). https://www.darwinproject.ac.uk/learning/11-14/darwin-and-slavery#:~:text=Darwin%20believed%20that%20the%20enslavement,family%2C%20supported%20the%20abolition%20movement.
- “Charles Darwin (1809-1882)”. Internet Encyclopedia of Philosophy (ND). https://iep.utm.edu/darwin/
- “About Darwin Day”. International Darwin Day (ND). https://darwinday.org/
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