Will Cloning End Human Evolution?

Article excerpt

Cloning is not only less fun than sex, it would freeze evolution and destroy our chances for survival in the future.

The recent cloning of the first mammal brings the prospects of human cloning closer to reality. Now the public should ponder the implications. Among these, the most important is the effect on our future evolution.

Cloning will be attractive because of some medical uses. Genetic replicas of geniuses might also benefit society. On the other hand, ruthless and egocentric despots may replicate themselves millions of times over. Cloning on a large scale would also reduce biological diversity, and the entire human species could be wiped out by some new epidemic to which a genetically uniform population was susceptible.

Beyond these important but obvious results, cloning raises problems that go to the core of human existence and purpose. One important fact to recognize is that cloning is asexual reproduction. It therefore bypasses both the biological benefits of normal reproduction and the emotional, psychological, and social aspects that surround it: courtship, love, marriage, family structure. Even more importantly, if cloning became the main mode of reproduction, human evolution would stop in its tracks.

In sexual reproduction, some of the genetic material from each parent undergoes mutations that can lead to entirely new biological properties. Vast numbers of individual combinations become possible, and the requirements of survival - and choices of partners by the opposite sex - then gradually select which features will be passed on to the following generations.

Cloning will, in contrast, reproduce the same genetic makeup of an existing individual. There is no room for new traits to arise by mutation and no room for desirable features to compete and win by an appeal to the judgment of the opposite sex. The result: Human evolution is halted.

Is it necessary for the human species to evolve further? Absolutely! We are certainly far from achieving perfection. We are prone to diseases, and the capacity of our intelligence is limited. Most importantly, human survival will depend on our ability to adapt to environments beyond Earth - that is, in the rich new worlds of outer space.

Some people question whether we can save ourselves from man-made environmental disasters on Earth, whose resources are already pressured by human population growth. And limiting the population to one planet puts us at risk of extinction from all-out nuclear or biological warfare, climate change, and catastrophic meteorite impacts. …