One of the most common arguments against cloning and gene manipulation is that humans should not "play God." Such arguments presume It is for God to give life and not for man to alter the direction of it. The often overlooked fact, however, is that we are already "giving life" and altering genes and manipulating the future species of mankind--just not for the better. Technology and medicine have been extremely invaluable in the survival of many people, but that is exactly the problem. The concepts of Natural Selection (not referring to evolution at this point) are completely defiled by technology. By preventing the deaths or aiding the survival of persons less gifted genetically, we continue the propagation of those genes and further create such people who are similarly less gifted.
We are currently manipulating the gene pool and "playing God" by interfering with the natural processes of life that would otherwise keep a species strong and healthy. This is ironically both fortunate and unfortunate but it will continue to get worse if we don't devise a plan of action to correct it. More cancer, more loss of vision, more deformities, more ailments, more allergic reactions, and so on will continue to plague our populations such that it will become routine to have surgeries every few years starting from birth. It is already occurring but we mostly ignore it because it is such a slow transition. It's like the frog in the pot. Even if we can cure cancer, that will not stop people from getting cancer. If we can regrow a limb, that won't stop children from being born limb-deficient. We now completely rely on technology to aid us in the ways we've shaped, directed, and corrupted our gene pool. There is no survival of the fittest among humans; there is merely survival for all.
So what is the solution here? I'm certainly not one for ethnic cleansing. It's not about ethnicity anyway. We need to "cleanse" the gene pool but that doesn't mean we have to do so unethically. We are already playing God with who should live; now we need to play God and decide who and what we want our future species to be. Either that or let nature do the job, but that is rather crude. Do we want our future species to be obese, depressed, wheel-chair-ridden individuals where machines fulfill their every need and surgery keeps them alive every 2 years? Or do we want people who are strong, intelligent, healthy, compassionate, loving, and so on? Forget all the sci-fi horror stories and negative hype. Researching genes and manipulating them for the better is not going to end in world-wide killing machines who have no sympathy for their "lesser" counterparts. Rather, they'll probably be extremely grateful that we prevent them from suffering so many similar plights as ourselves.
Education and research are the key. We can educate people to make decisions that are beneficial to mankind. We can educate people to research, identify, and manipulate genes for the better. Couples would be able to learn whether or not their genes have certain deficiencies and decide for themselves if they want to have children, adopt someone else's, or modify their genes to prevent their children from suffering unnecessarily. It doesn't have to be like the movie Gattaca. If we really wanted, we can ensure that manipulations only occur on a health basis and not to change personality or physical attributes. Personally, however, I look forward to improving life and not merely keeping it alive. We could do so much good in the world and for our future children if we put aside the complaint that it is not for us to decide. We are already deciding but we are making it worse. Let us now make it better. Without trying to be cliché, literally think of the children! I'm sick of the suffering and early death of children. I'm sick of children being born limb-deficient like my own. I'm sick of brutes controlling the world with violence because they lack intelligence. It's time we take some responsibility for our future. Let us benefit mankind rather than merely keeping it alive.