Wallace

The theory of evolution by natural selction was proposed independently and at the same time by Darwin and Wallace. Any other scientific  theory discovered by two author would  be named wallace-darwinism, but we speak simply of darwinism. Darwin, that was rather ambitious, did all the possible to obscue his fellow, and Wallace - he was socialist - from his part didnt'care. But apart from the human weaknesses, there was a slight difference in accent in the presentation of Darwin and Wallace. Darwin spoke of survival of the fittest and was overtly malthusian. This appealed to the readers of the time, and rapidly led to social darwinism (that I dare say is still with us). Wallace spoke of tendency of varieties to depart indefinitely from the original type, a statistical approach implying shifts in frequencies and extremely modern, but less intuitive to readers of the day.