Scientists in the UK have applied for a three-year license to create embryos by fusing cow eggs with human DNA. 
      The hybrid embryos would be used for stem cell research and wouldn't be allowed to develop for more than a few days. But there are some critics who are saying that this process is "unethical and potentially dangerous." 
      Stem cell research is considered one of the most promising areas of medical science. Scientists need to harness stem-cells to treat diseases such as Parkinson's disease, strokes and Alzheimer's disease. In order to do this they need to have access to thousands of embryos for their research. But there is a shortage of human eggs for research and in order for them to obtain them women would have to undergo surgery. So scientists want to use cow eggs as a replacement.
      They would insert human DNA into a cow's egg which has had its genetic material removed. Then create an embryo in the same way that scientists produced Dolly the Sheep. The embryo created would be 99.9% human.
      The goal is to remove stem cells from the embryo when it is about six days old and then destroy it.