In early 1970, Bob Lewis and Gerald Casale formed the idea of the "devolution" of the human race after Casale's friend Jeffrey Miller was killed by Ohio National Guardsmen firing on a student demonstration. Casale joined Devo in 1973, after being recruited by his brother Gerald. After the band underwent a few line-up changes, Bob Casale became part of the most popular five-piece incarnation, which consisted of two sets of brothers, the Mothersbaughs (Mark and Bob) and the Casales (Gerald and Bob), along with drummer Alan Myers. Casale later claimed that they formed the band because "it was a more immediate way of self-expression that required less money and no outside permission."