[lennytheduck]

Something that people don't realize is that cloning has been going on in laboratories for a lot longer than when Dolly first came on the scene courtesy of Wilmut and Co. The large difference is that it was done with bacteria and other microorganisms, nothing on a scale so large as a sheep.

What came along with Dolly, and the reason it was such a significant breakthrough, is of course that sheep are fairly large mammals and if you can do it in one of them, you could almost certainly do it in a human too right? But the researchers responsible for Dolly took years and years to do it with a whole bunch of tries (for some reason the number 40 comes to mind but I can't recall for sure).

A "clone" is an exact (almost) genetic replica, meaning that is has the same chromosomes, genes, codons, nitrogenous base sequence, etc. Genes code for proteins, which are really responsible for everything that happens in the body in one way or another. Each gene codes for a protein which has its own specific structure, which in turn is directly related to its structure. For example, people with Cystic Fibrosis have a genetic mutation which does not allow them to produce a functional protein that is responsible for transporting chloride ions across plasma membranes. Cl- ions are very important in the movement of water going across the membrane, and without them water and other solutes tend to stay within the cell when they should be transported out. Without the water, mucus cannot be washed away and instead builds up, which is why people with CF have problems have such large pulmonary problems.

So lets you had CF and you were cloned. Now your clone has to go through a whole life cycle (infancy, toddler, child, pre-adolescent, teenager, young adult, adult) before he will be anything even like you. He will have "inherited" the same alleles for the gene that codes for CF function as you. But he may have CF much worse than you. He may die at the age of 5 from it. He may never have serious problems and be able to exist on some simple meds alone. His symptoms may also be very similar to your own.

Within the genome exist genes known as transposons, or in layman's terms, "jumping genes." They bounce around throughout the genome, often copying themselves in random positions or sometimes moving to completely new spots. Also, the protein responsible for DNA replication, RNA Polymerase III, makes an error every 10*8 nitrogenous base, in many cases causing a point mutation that will change an amino acid, the monomeric unit of proteins. A single AA change can cause a protein to function differently, or even to lose function completely. Sickle cell anemia is one example of this, where a Valine AA residue is found in normal hemoglobin while a Glutamine AA residue replaces it in those who have the sickle trait (though, mind you, hemoglobin is inherited and is absurdly unlikely to change during your lifetime, but its the idea that counts).

All of this said, when your liver finally kicks it at the age of 68 and X number of scotches on the rocks, even if you have been cloned there is no assurance that your clone will be able to give you a transplant. There is also a very slim chance that your clone will have worked successfully on teh first try, not to mention the surrogate mother that would have to birth it. I don't know what goes on in the dark recesses of the world, but even when I search the depths of my imagination, it is hard for me to fathom that a human has been successfully cloned. There are just too many variables working against its happening. That said, we are very much a product of our environment, and even if it was successful, the chance of the clone being like its original is miniscule at best.