Ever since the Soviet Union shocked the world in 1957 by launching Sputnik, the first human-made satellite, the rate of scientific progress in medicine, computer technology, telecommunications and biology has been astounding. Nowhere are advances more spectacular than in genetics. My daughter, a third-year student in university, is doing experiments in her genetics course with DNA, the genetic material, that I never dreamed would be possible in my lifetime when I graduated with a PhD in genetics in 1961. The great science writer, Isaac Asimov, once remarked in the 1970s that to estimate how far science will advance by the end of the century, take the wildest estimates, then double that and double it again.
Nothing illustrates it better than cloning.
The concept is very simple. At fertilization, an egg and a sperm unite to form a cell containing all the information needed to make a complete individual. That cell will then divide numerous times, faithfully duplicating and passing on to all cells, all of the genetic information in the original fertilized egg. In a human adult, this comes to some 60 trillion cells, each one of which carries the entire genetic blueprints that were in the sperm and egg. Thus, in principle, every cell in our bodies contains all the genes needed to turn it into a full human being.