The problem with waiting until harm is demonstrated is that we don't know what form it might take. Given the current free-for-all of genetic experimentation, it

The problem with waiting until harm is demonstrated is that we don't know what form it might take. Given the current free-for-all of genetic experimentation, it's only a matter of time until something we do has a significant unintended effect on an ecosystem. Unlike DDT, we won't necessarily be able to just stop the intervention and wait for things to go back to the way they were.