Difficulties will occur to every one, with respect to this theory." Darwin's contemporaries were eight characters, Alfred Russel Wallace, Charles Lyell, Ernst Haeckel, Gregor Mendel, Mary Anning, Robert Chambers, Thomas Henry Huxley and Thomas Malthus, and the two potential difficulties that might have troubled darwin's contemporaries were the lack of transitional forms and insufficient time for different forms to evolve.
