Can Genetically Altered DNA be Identified?

I spent a while researching this question and tried rewording it many different ways and still had trouble finding the information I was hoping to find. You may be familiar with DNA sequencing, which allows the genetic code of an organism to be mapped out with the help of a computer. This process allows scientists to sequence the entire genome of an organism. These genetic maps would allow trained professionals to find specific genes of interest or to identify mutations. Many organisms have molecular markers that can be found at specific locations on their genome. Molecular markers are specific fragments of DNA that can be identified with the whole genome of an organism. These molecular markers often stay linked to particular characteristics during genetic crosses which allows scientists to use these markers to identify the genetic makeup of organisms. So scientists can tell if the genome of a particular organism has been altered by looking for markers of traits that may have been added. These markers are also used to select individual plants or animals that carry a particular gene that affects the expression of an economically important characteristic. Scientists can tell if an organism has been genetically modified but the average consumer has no way of telling. There has been much debate over whether genetically modified organisms that are sold for human consumption should be labeled. I believe that they should be labeled, if they are safe to eat, why would companies not want to label their products?

“Scientific Facts on Genetically Modified Crops.” GreenFacts. FAO, 2004. Web. 10 Apr. 2011. <http://www.greenfacts.org/en/gmo/gmo-greenfacts-level2.pdf>