In 1831, a young scientist named Charles Darwin sailed around the world on a ship called the Beagle. The trip lasted five years. On the Galapagos Islands near South America, Darwin noticed something strange about the finches. Each island had finches with different beak shapes. Some had thick beaks for cracking seeds. Others had thin beaks for catching insects. Darwin spent twenty years thinking about what he had seen. He concluded that animals slowly change over many generations. The ones best suited to their environment survive and have babies. Those babies inherit the helpful traits. Darwin called this process natural selection. He published his ideas in a book called On the Origin of Species in 1859. Many scientists praised the book. Others were angry because it challenged old beliefs about how life began. Darwin continued his research quietly at home in England. He studied earthworms, orchids, and barnacles with the same careful observation he had used on the Galapagos. He died on April 19, 1882. Was buried in Westminster Abbey alongside some of the greatest scientists in British history.