Life is a condition that distinguishes organisms from inorganic objects, i.e. non-life, and dead organisms, being manifested by growth through metabolism, reproduction, and the power of adaptation to environment through changes originating internally. - Wikipedia

 

Personally, I think that the answer is yes. Life is quite probably the most powerful force ever known to man, and life as a while can't be destroyed. Sure, maybe a few million species could be wiped out, but there are, what, another billion that are still thriving and continuing to adapt to their environment. The simple fact is that life is built to survive, and no matter how hard you try, you might get rid of a small chunk, but the rest will just keep on going.

Seriously. The worst that can be done is everything up till the amoebic level could be destroyed, and then evolution starts all over again. >_>

Yup - evolution & natural selection are processes that automatically pick out those who are best suited to their environment.

 

One example is that if you use an antibiotic on a bunch of bacteria, there might be one or two of those bacteria that are antibiotic resistant. Since you killed all the rest of the bacteria, those ones are free to reproduce and you end up with a whole bunch of antibiotic resistant bacteria.