Charles Darwin was an English naturalist born in Shrewsbury, England on February 12 of 1809. In his expedition around the world in 1831, he gathered and recorded different characteristics of the specimens and plants he found, which helped him come up with the theory of natural selection. His theory of natural selection consists of the species and its characteristics that make them survive in their environment due to their ability of adaptin. Eventually, the strongest organism will survive and will keep passing through generations to generations their helpful characteristics. Natural selection is known as"the most important evolutionary mechanism". He wrote a book about his theory called "On the Origins of Species by Means of Natural Selection", which took him about twenty years to write. His theory made a lot of sense in my opinion, but during his days, people strongly believed that the ultimate truth was what the church believed in. The church believed that God made everything from animals to plants, which explained that there is no such thing as evolution. Therefore, people thought that Darwin's theory was insulting to the church. This is why Charles Darwin kept his work to himself.Charles Darwin was anguished to finish developing his theory because he was besides her 10 year old daugher's death, he was rejected by his the people that surrounded him because of religious beliefs. He was hurting his beloved ones. He was also sick and eventually he became crazy.