Planets are commonplace, and life may be as well. It seems only reasonable to conclude that intelligent life will also be widespread. He is well known for proposing the Drake Equation. The Drake Equation gives a means for estimating how many communicating civilizations may be out there. The results can vary widely, depending on the optimism of the numbers you yourself plug in.
Evolutionists are no exception.
Evolutionists tend to believe that whenever a civilization has evolved to the point where it has the technology to destroy itself, it will. Or maybe life is common, but too often destroys itself as technology becomes too powerful to handle. Once life does exist, however, it is quite evident from our own evolutionary history that it is quite adaptable and tenacious. The jury is still out, however, on how long species survive once they have developed intelligence and powerful technology. 6 Technology, they believe, is deadly.