Evolutionary development is sometimes thought of as exhibiting an inexorable trend towards higher, more complex, and normatively worthwhile forms of life. This paper explores some dystopian scenarios where freewheeling evolutionary developments, while continuing to produce complex and intelligent forms of organization, lead to the gradual elimination of all forms of being that we care about. We then consider how such catastrophic outcomes could be avoided and argue that under certain conditions the only possible remedy would be a globally coordinated policy (...) to control human evolution by modifying the fitness function of future intelligent life forms. (shrink)