In 1865, following the publication of Darwin’s The Origin of Species, the Austrian botanist and monk Gregor Mendel published his laws of inheritance, the result of long experiments and observations. However, these laws attracted the attention of the scientific world only toward the end of the century. Not until the early 20th century did the entire scientific world accept the accuracy of these laws. This represented a major dilemma for Darwin’s theory, which sought to account for the concept of beneficial characteristics, based on Lamarck.
But Mendel opposed not only Lamarck’s model of evolution, but also Darwin’s model. As stated in an article titled “Mendel’s Opposition to Evolution and to Darwin,” published in the Journal of Heredity,Mendel was against the theory of evolution. Darwin suggested that all life had evolved from a common ancestor, while Mendel believed in creation. (SOURCE)