Charles Darwin, the person who wrote "On the origin of species" is the person who personifies this scientific theory.
The American Museum of Natural History has created a significant resource bringing the scientific manuscripts of Charles Darwin together on the Internet for everyone to see.
For all those people who have no clue what this scientific theory is about, it is wonderful that they have at least the opportunity to learn what Mr Darwin said in his own time. When they object to the evolution theory, they have to appreciate that science did not abandon this theory and has amassed a wealth of additional supporting evidence not known at the time of Mr Darwin.
The significance of this new wonderful resource is that is shows the humble beginnings of a theory that is still as vibrant as it used to be. It is still as controversial as it used to be but now it is possible to learn about how this theory evolved during the lifetime of Mr Darwin. To learn what science has learned in additional knowledge, you have to study the subject itself.
Many people have opposed the evolution theory. It would be a worthy Wikisource project to accumulate the original sources of the ideas proposed against the evolution theory.