THE mere mention of human cloning is enough to make the hairs on many a neck stiffen. But clones do not have the exact genetic material of their donor, because a key bit of DNA actually lives outside the cell nucleus, and is not removed when the cloning procedure takes place. This is the mitochondrial DNA which is passed down by the mother. Of course, environment also plays a key role in how people turn out, and while the nature-nurture debate continues, we will not be able to say for certain how great each role is. Since recent reports have stated that the estimated number of genes is only about 30,000, what really shapes us is probably how our genes interact with one another and the environment, something which would be impossible to duplicate.
Clones also face considerable health risks, with most animal clones dying even before they are born.
This could be because when the same specimen is cloned repeatedly, errors in genetic material tend to accumulate in the cells, making the clone weaker. The survivors often face a wide range of abnormalities, including heart or lung ailments, and even so-called healthy specimens risk aging prematurely because the cells could inherit the age of their genetic mothers. That is why a mad scientist would never be able to create another Hitler by cloning. Apart from the fact that he would need some frozen or preserved cells from the man himself, differences in the womb environment, as well as the clone's upbringing, would mean that the clone would not act, think or even look like the original. People who reject the idea of cloning as alien or playing God may be surprised to learn that Mother Nature does it all the time.