nces in the right-hand column. Use each word only once. 1. High-mass main-sequence stars have a more distant and wider ___ than low-mass stars. 2. Sky surveys looking for radio signals generated by technology are part of the ___ 3. The ___ is designed as a way of estimating the number of intelligent civilizations in the Milky Way. 4. The notion that living organisms advantages that give them greater reproductive success (in some local environment) will survive while others perish is an example of what Darwin called ___. 5. One of the key premises for the ___ is that living organisms are able to produce far more offspring than their environment can support. 6. The different time periods of the ___ are defined by changes in fossils found form those time periods. 7. Incoming ultraviolet light from the Sun can cause a ___ in a living organism's DNA that can affect its ability to survive and reproduce. a. mutation b. theory of evolution c. natural selection d. geological time scale e. habitable zone f. drake equation g. search of extraterrestrial intelligence