The theory of natural selection was popularised by the book ‘Origin of Species’, which was written by

The book 'The Origin of Species' was written by Darwin. Lamarck gave the theory of inheritance of acquired characters, which was initially opposed. Later, this theory was supported by both Darwin and Alfred Wallace. At that time, the book 'The Origin of Species' gave a strong evidence to support Lamarck’s theory. Mendel, on the other hand, worked only on genetics and traits. But the theories of Mendel and Darwin unfortunately were never mixed; else the evolution and its genetic basis may have been understood much before.