Evolution: Not Inevitable After All?
The theory of evolution is based on the concept of genetic variation and random mutation. Without the combination of different traits and genes it would be impossible for the world to exist as it does today with so many different populations, species, and environments.
In his book, What Evolution Is, Mayr writes, “evolution is inevitable” (5). However, humans have risen to a level of intelligence higher than that of any other organism, and have been able to manipulate nature into science. One of the most famous and recent debates in the science community is on the topic of cloning, and what people can achieve using it. Cloning was first viewed as something probable in 1997 when Scottish scientists produced the clone of a sheep, “Dolly,” the first clone of a mammal. Since then, the concept of cloning animals and humans has been debated in the media, the scientific community, receiving both applause and criticism.
Sometimes clones are created naturally, like in the circumstance of identical twins, both of which contain the exact same genetic information (2). Cloning, however, is the process of synthetically creating a genetically identical duplicate of an original organism by copying its nucleic DNA structure. The topic of cloning is brought up rather generally in the media, and usually focuses on organism cloning; but there are actually two other types of cloning: molecular, and genetic. Molecular cloning refers to the extracting of pieces of DNA from and organism and copying it within that organism. Genetic cloning is used mainly in vitro procedures where a whole group of cells is produced from just one original cell. Organism cloning is the process of creating an entirely new organism with the exact same genetic information as the original organism. In this sort of reproduction, only one “parent” is involved and is known as a type of agamogenesis or asexual reproduction (4).
Dolly, the sheep clone, was produced by means of organism reproductive cloning technology, involving a process called somatic cell nuclear transfer (SCNT). Ian Wilmut, a Scottish scientist at Roslin Institute made his discovery public on February 23, 1997, stating his success of the SCNT method. SCNT involves replacing the nucleus of a sheep egg with that of an adult sheep somatic cell and then shocking the cell with an electric current or chemical treatment to initiate cell division. SCNT is not just used for the cloning of organisms but also can be used for medical purposes such as producing cartilage cells for knee injuries and gene therapy (1, 2).
Because of some of the remarkable successes in animal cloning, the suggestion has risen that there should be a way to clone human beings as well. Being able to successfully clone humans or parts of humans would dramatically improve and catalyze biomedical research and especially stem cell research. Stem cells are particularly important to the body because they are used to repair damaged or diseased tissues and organs in the body. Scientists have been trying to use cloning as a way of reproducing stem cells so that they can be used in medical purposes to repair the tissues of people who are lacking stem cells or have an injury to an organ that will not naturally repair, such as a spinal cord injury. Obviously, with the changes it would make to the medical world, cloning could change lives for many people. For example, cloning could make it possible for infertile couples to have children or to replace a deceased child (3). It is possible that in the future therapeutic cloning technology can be used to grow entire healthy organs to replace diseased ones in patients with degenerative diseases. (1).
Despite the claims the scientific community is making that cloning can and may assist in the development of medical advances, cloning is radically going against the grain of natural evolution. One of the main hopes is for cloning to improve the farming of animals, by cloning the best and strongest animals, instead of just breeding them randomly or somewhat selectively. However, this new technique is contrary to the course of evolution. Through natural selection, genetic variation and random mutation evolution will continue to change the genetic makeup of any given species, naturally making them better off than any clone. While the farmers are looking to improve their herds based on phenotypes, or physical attributes, the genotypes, or the genetic makeup, of their clones may become more and more susceptible to certain diseases or limitations that otherwise could have been survived by animals that were not cloned.
Mayr says in his conclusion that evolution is “considered as something unexpected” (5). Cloning is not unexpected. With cloning, we know exactly what the outcome will be. It will be the same as before, as will the next clone, and the next. If humans are able to clone successfully, will certain aspects of evolution be eliminated, making it not so inevitable any more?
1. "Cloning Fact Sheet." Human Genome Project Information. 10 Feb. 2007
2."learn.genetics.utah.edu/units/cloning/whatiscloning/." Genetics Science
Learning Center. 10 Feb. 2007 <http://learn.genetics.utah.edu/units/
3. "Why Clone?" Genetics Science Learning Center. 10 Feb. 2007
4. "Cloning." Wikipedia. 10 Feb. 2007 <http://en.wikipedia.org/w/
5. Mayr, Ernst. What Evolution Is. New York: Basic Books, 2001.