i dont think this in the right section, but o well.
i think Some people are against it cause it 'interferes with nature'
a potential advantage is that you can insert it into bacteria and get the bacteria to make the protein product of the gene (which could be things like insulin)....
Yeah i agree, there have been ethical issues. Religious beliefs also. Many people believe that interfering with nature means that we are changing the natural things of how god wanted everything to be. When the desired gene is obtained there will advantages for the organisms that have the trait.
Another concerns is genetically modified food and organisms that may have a long term impact on our society.
Genetic engineering has also been debated in our society today due to an organism having advantages over another.