1 in 1865 that traits do not mix like paint when they are handed down from parents to offspring, but rather are shuffled like cards. The concept of the unmixable source of a trait (say, whether peas would be smooth or wrinkled) was given the name gene, and Mendel's important observation was that the particular forms of genes usually did not change as they were passed from parents to offspring. This kind of faithful inheritance of traits, and shuffling instead of mixing of genes, allows populations to preserve diversity, instead of washing all traits out to some average form.
Darwin contemporaneously (1859) 2 had argued that the infrequent variations that do occur as traits are passed from parent to offspring need not be directed in order to enable adaptation. The greater reproductive success of individuals with better-adapted traits would be ...
