Why did Charles Darwin talk about pigeons (how breeders produced many shapes, sizes, and colors of pigeons, all starting from a wild pigeon) in his book On the Origin of Species?
http://www.nhm.ac.uk/nature-online/collections-at-the-museum/museum-treasures/charles-darwin-pigeons/
Charles Darwin talked about pigeons in his book, "On the Origin of Species," because they provided tangible evidence for his theory of natural selection and the process of evolution. Pigeons were a prime example of how artificial selection, or selective breeding by human breeders, could lead to significant variations in a species.
By studying pigeons, Darwin aimed to demonstrate how breeders had successfully produced diverse breeds over centuries, all descending from a common ancestor, the wild rock pigeon. He noticed that breeders selectively bred pigeons for specific traits, such as size, shape, and color, and observed that these traits were then passed down to subsequent generations. This process mirrored the natural mechanisms of variation, inheritance, and selection that occur in the wild.
Darwin used pigeons as proof that if humans could intentionally shape the characteristics of a species through selective breeding, nature could accomplish similar changes through the natural selection of heritable traits. This provided a valuable analogy to explain how species could evolve over time in response to their environment, leading to the diversity of life we see today. The pigeon example showed that the principles of variation and selection were not limited to domesticated animals but could be applied to all living organisms.