Prior to Darwin
Prior to Darwin’s theory of evolution, there were many varied ideas about how life as we know it came to be. Visionaries in Ancient Greece some 2600 years ago had already reasoned that humans could not have appeared on Earth in their current form, and must have originated from some previous ancestor. Some proposed that humans were born from other creatures entirely, while others suggested that various combinations of species (for example, cattle with human heads) originally existed on Earth and competed with one another until only some species remained.
Jumping ahead to 1830, a famous debate took place in Paris, where two famous scientists argued about whether or not organisms could change over time, to explain the oddly coincidental similarities between some species. Many other discussions and proposed ideas existed, and as you can see, some of these ideas began to touch on something similar to what we now understand as “evolution”, although they were not totally correct and/or failed to explain how evolution could have occurred.
In the next short reading, you'll read more about the observations and conclusions Darwin made in his work. As with all scientists, though, his work did not exist in a vacuum. Darwin was influenced by a variety of different ideas and people, including the following:
James Hutton
A geologist who proposed the concept of "deep time", which proposed that Earth was shaped by geological forces over extremely long periods of time (suggesting that Earth was millions of years old!)
Charles Lyell
Another geologist who popularized "uniformitarianism", the idea that geological processes that we see shaping Earth today also likely existed throughout Earth's ancient history (and shaped it back then, too!)
Jean-Baptiste Lamarck
A naturalist (like Darwin!) who proposed the Inheritance of Acquired Characteristics. This states that an existing organism undergoes change during its lifetime based on use or disuse of a trait/body part. Those traits could then be passed down to their offspring.
Thomas Malthus
An economist who argued that there was a "struggle for existence", because human population growth eventually outpaces the available food and other resources. Eventually, population growth would lead to food scarcity and overcrowding.
Alfred Russel Wallace
Another naturalist who also sailed around the world to study nature like Darwin, at roughly the same time as him. He actually came up with the same general ideas (evolution by natural selection) as Darwin, completely independently, based on his own observations and conclusions. We'll talk more about him together in class! :)
