a organisms for most of the next one
a much higher rate than the beings thatgave it birth. The transformation time from tree-shrew, to ape, to human far exceeds the timefrom analytical engine, to calculator, to computer. But science, in the past, has always remaineddistant. It has allowed for advances in production, transportation, and even entertainment, butnever in history will science be able to so deeply affect our lives as genetic engineering willundoubtedly do. With the birth of this new technology, scientific extremists and anti-technologists have risen in arms to block its budding future. Spreading fear by misinterpretationof facts, they promote their hidden agendas in the halls of the United States congress. Geneticengineering is a safe and powerful tool that will yield unprecedented results, specifically in thefield of medicine.
It will usher in a world where gene defects, bacterial disease, and even agingare a thing of the past. By understanding genetic engineering and its history, discovering itspossibilities, and answering the moral and safety questions it brings forth, the blanket of fearcovering this remarkable technical miracle can be lifted. The first step to understanding genetic engineering, and embracing its possibilities forsociety, is to obtain a rough knowledge base of its history and method. The basis for altering theevolutionary process is dependant on the understanding of how individuals pass oncharacteristics to their offspring. Genetics achieved its first foothold on the secrets of nature’sevolutionary process when an Austrian monk named Gregor Mendel developed the first “laws ofheredity.” Using these laws, scientists studied the characteristics of organisms for most of the next one hundred years following Mendel’s discovery. These early studies concluded that eachorganism has two sets of character determinants, or genes (Stableford 16).
For instance, inregards to eye color, a child could receive one set of genes from his father that were encoded oneblue, and the other brown. The same child could also receive two brown genes from his mother. The conclusion for this inheritance would be the child has a three in four chance of havingbrown eyes, and a one in three chance of having blue eyes (Stableford 16). Genes are transmitted through chromosomes which reside in the nucleus of every livingorganism’s cells. Each chromosome is made up of fine strands of deoxyribonucleic acids, orDNA. The information carried on the DNA determines the cells function within the organism. Sex cells are the only cells that contain a complete DNA map of the organism, therefore, “thestructure of a DNA molecule or combination of DNA molecules determines the shape, form, and function of the organism’s offspring ” (Lewin 1).
DNA discovery is attributed to the researchof three scientists, Francis Crick, Maurice Wilkins, and James Dewey Watson in 1951. Theywere all later accredited with the Nobel Price in physiology and medicine in 1962 (Lewin 1). “The new science of genetic engineering aims to take a dramatic short cut in the slow process of evolution” (Stableford 25). In essence, scientists aim to remove one gene from anorganism’s DNA, and place it into the DNA of another organism. This would create a new DNAstrand, full of new encoded instructions; a strand that would have taken Mother Nature millionsof years of natural selection to develop. Isolating and removing a desired gene from a DNAstrand involves many different tools.
DNA can be broken up by exposing it to ultra-high-frequency sound waves, but this is an extremely inaccurate way of isolating a desirable DNA section (Stableford 26). A more accurate way of DNA splicing is the use of “restrictionenzymes, which are produced by various species of bacteria” (Clarke 1). The restrictionenzymes cut the DNA strand at a particular location called a nucleotide base, which makes up aDNA molecule. Now that the desired portion of the DNA is cut out, it can be joined to another strand of DNA by using enzymes called ligases.
The final important step in the creation of anew DNA strand is giving it the ability to self-replicate. This can be accomplished by usingspecial pieces of DNA, called vectors, that permit the generation of multiple copies of a totalDNA strand and fusing it to the newly created DNA structure. Another newly developed method, called polymerase chain reaction, allows for faster replication of DNA strands and doesnot require the use of vectors (Clarke 1).
The possibilities of genetic engineering are endless. Once the power to control theinstructions, given to a single cell, are mastered anything can be accomplished. For example,insulin can be created and grown in large quantities by using an inexpensive gene manipulationmethod of growing a certain bacteria. This supply of insulin is also not dependant on the supplyof pancreatic tissue from animals.
Recombinant factor VIII, the blood clotting agent missing inpeople suffering from hemophilia, can also be created by genetic engineering. Virtually allpeople who were treated with factor VIII before 1985 acquired HIV, and later AIDS. Beingcompletely pure, the bioengineered version of factor VIII eliminates any possibility of viral infection. Other uses of genetic engineering include creating disease resistant crops, formulatingmilk from cows already containing pharmaceutical compounds, generating vaccines, andaltering livestock traits (Clarke 1). In the not so distant future, genetic engineering will becomea principal player in fighting genetic, bacterial, and viral disease, along with controlling aging,and providing replaceable parts for humans. Medicine has seen many new innovations in its history.
The discovery of anestheticspermitted the birth of modern surgery, while the production of antibiotics in the 1920sminimized the threat from diseases such as pneumonia, tuberculosis and cholera. The creation of serums which build up the bodies immune system to specific infections, before being laid lowwith them, has also enhanced modern medicine greatly (Stableford 59). All of these discoveries,however, will fall under the broad shadow of genetic engineering when it reaches its apex in themedical community. Many people suffer from genetic diseases ranging from thousands of types of cancers, toblood, liver, and lung disorders. Amazingly, all of these will be able to be treated by geneticengineering, specifically, gene therapy.
The basis of gene therapy is to supply a functional geneto cells lacking that particular function, thus correcting the genetic disorder or disease. Thereare two main categories of gene therapy: germ line therapy, or altering of sperm and egg cells,and somatic cell therapy, which is much like an organ transplant. Germ line therapy results in apermanent change for the entire organism, and its future offspring. Unfortunately, germ linetherapy, is not readily in use on humans for ethical reasons. However, this genetic methodcould, in the future, solve many genetic birth defects such as downs syndrome.
Somatic celltherapy deals with the direct treatment of living tissues. Scientists, in a lab, inject the tissueswith the correct, functioning gene and then re-administer them to the patient, correcting theproblem (Clarke 1). Along with altering the cells of living tissues, genetic engineering has also provenextremely helpful in the alteration of bacterial genes. “Transforming bacterial cells is easier than transforming the cells of complex organisms” (Stableford 34).
Two reasons are evident forthis ease of manipulation: DNA enters, and functions easily in bacteria, and the transformedbacteria cells can be easily selected out from the untransformed ones. Bacterial bioengineeringhas many uses in our society, it can produce synthetic insulins, a growth hormone for thetreatment of dwarfism and interferons for treatment of cancers and viral diseases (Stableford 34). Throughout the centuries disease has plagued the world, forcing everyone to take part in avirtual “lottery with the agents of death” (Stableford 59). Whether viral or bacterial in nature,such disease are currently combated with the application of vaccines and antibiotics. These treatments, however, contain many unsolved problems. The difficulty with applying antibioticsto destroy bacteria is that natural selection allows for the mutation of bacteria cells, sometimesresulting in mutant bacterium which is resistant to a particular antibiotic.
This nowindestructible bacterial pestilence wages havoc on the human body. Genetic engineering isconquering this medical dilemma by utilizing diseases that target bacterial organisms. these diseases are viruses, named bacteriophages, “which can be produced to attack specific disease-causing bacteria” (Stableford 61). Much success has already been obtained by treating animalswith a “phage” designed to attack the E. coli bacteria (Stableford 60). Diseases caused by viruses are much more difficult to control than those caused bybacteria.
Viruses are not whole organisms, as bacteria are, and reproduce by hijacking the mechanisms of other cells. Therefore, any treatment designed to stop the virus itself, will alsostop the functioning of its host cell. A virus invades a host cell by piercing it at a site called a”receptor”. Upon attachment, the virus injects its DNA into the cell, coding it to reproduce moreof the virus. After the virus is replicated millions of times over, the cell bursts and the newviruses are released to continue the cycle. The body’s natural defense against such cell invasionis to release certain proteins, called antigens, which “plug up” the receptor sites on healthy cells.
This causes the foreign virus to not have a docking point on the cell. This process, however, isslow and not effective against a new viral attack. Genetic engineering is improving the body’sdefenses by creating pure antigens, or antibodies, in the lab for injection upon infection with aviral disease. This pure, concentrated antibody halts the symptoms of such a disease until thebodies natural defenses catch up. Future procedures may alter the very DNA of human cells,causing them to produce interferons. These interferons would allow the cell to be abledetermine if a foreign body bonding with it is healthy or a virus.
In effect, every cell would beable to recognize every type of virus and be immune to them all (Stableford 61). Current medical capabilities allow for the transplant of human organs, and evenmechanical portions of some, such as the battery powered pacemaker. Current science can evenre-apply fingers after they have been cut off in accidents, or attach synthetic arms and legs to allow patients to function normally in society. But would not it be incredibly convenient if thehuman body could simply regrow what it needed, such as a new kidney or arm? Geneticengineering can make this a reality.
Currently in the world, a single plant cell can differentiateinto all the components of an original, complex organism. Certain types of salamanders can re-grow lost limbs, and some lizards can shed their tails when attacked and later grow them again. Evidence of regeneration is all around and the science of genetic engineering is slowly masteringits techniques.
Regeneration in mammals is essentially a kind of “controlled cancer”, called ablastema. The cancer is deliberately formed at the regeneration site and then converted into a structure of functional tissues. But before controlling the blastema is possible, “a detailedknowledge of the switching process by means of which the genes in the cell nucleus areselectively activated and deactivated” is needed (Stableford 90). To obtain proof that such aprocedure is possible one only needs to examine an early embryo and realize that it knowswhether to turn itself into an ostrich or a human. After learning the procedure to control and activate such regeneration, genetic engineering will be able to conquer such ailments asParkinson’s, Alzheimer’s, and other crippling diseases without grafting in new tissues.
Thebroader scope of this technique would allow the re-growth of lost limbs, repairing any damagedorgans internally, and the production of spare organs by growing them externally (Stableford90). Ever since biblical times the lifespan of a human being has been pegged at roughly 70years. But is this number truly finite? In order to uncover the answer, knowledge of the processof aging is needed. A common conception is that the human body contains an internal biologicalclock which continues to tick for about 70 years, then stops. An alternate “watch” analogy couldbe that the human body contains a certain type of alarm clock, and after so many years, thealarm sounds and deterioration beings.
With that frame of thinking, the human body does notbegin to age until a particular switch is tripped. In essence, stopping this process would simplyinvolve a means of never allowing the switch to be tripped. W.
Donner Denckla, of the RocheInstitute of Molecular Biology, proposes the alarm clock theory is true. He provides evidencefor this statement by examining the similarities between normal aging and the symptoms of ahormonal deficiency disease associated with the thyroid gland. Denckla proposes that as we getolder the pituitary gland begins to produce a hormone which blocks the actions of the thyroidhormone, thus causing the body to age and eventually die. If Denckla’s theory is correct,conquering aging would simply be a process of altering the pituitary’s DNA so it would never beallowed to release the aging hormone.
In the years to come, genetic engineering may finallydefeat the most unbeatable enemy in the world, time (Stableford 94). The morale and safety questions surrounding genetic engineering currently cause this newscience to be cast in a false light. Anti-technologists and political extremists spread falseinterpretation of facts coupled with statements that genetic engineering is not natural and defiesthe natural order of things. The morale question of biotechnology can be answered by studyingwhere the evolution of man is, and where it is leading our society. The safety question can be answered by examining current safety precautions in industry, and past safety records of manybioengineering projects already in place.
The evolution of man can be broken up into three basic stages. The first, lasting millionsof years, slowly shaped human nature from Homo erectus to Home sapiens. Natural selectionprovided the means for countless random mutations resulting in the appearance of such humancharacteristics as hands and feet. The second stage, after the full development of the humanbody and mind, saw humans moving from wild foragers to an agriculture based society. Naturalselection received a helping hand as man took advantage of random mutations in nature and bredmore productive species of plants and animals. The most bountiful wheats were collected andre-planted, and the fastest horses were bred with equally faster horses.
Even in our recenthistory the strongest black male slaves were mated with the hardest working female slaves. Thethird stage, still developing today, will not require the chance acquisition of super-mutations innature. Man will be able to create such super-species without the strict limitations imposed by natural selection. By examining the natural slope of this evolution, the third stage is a naturaland inevitable plateau that man will achieve (Stableford 8).
This omniscient control of ourworld may seem completely foreign, but the thought of the Egyptians erecting vast pyramidswould have seem strange to Homo erectus as well. Many claim genetic engineering will cause unseen disasters spiraling our world intochaotic darkness. However, few realize that many safety nets regarding bioengineering arealready in effect. The Recombinant DNA Advisory Committee (RAC) was formed under theNational Institute of Health to provide guidelines for research on engineered bacteria forindustrial use. The RAC has also set very restrictive guidelines requiring Federal approval if research involves pathogenicity (the rare ability of a microbe to cause disease) (Davis, Roche69).
“It is well established that most natural bacteria do not cause disease. After many years ofexperimentation, microbiologists have demonstrated that they can engineer bacteria that are just as safe as their natural counterparts” (Davis, Rouche 70). In fact the RAC reports that “there hasnot been a single case of illness or harm caused by recombinant engineered bacteria, and theynow are used safely in high school experiments” (Davis, Rouche 69).
Scientists have alsodevised other methods of preventing bacteria from escaping their labs, such as modifying thebacteria so that it will die if it is removed from the laboratory environment. This creates a shieldof complete safety for the outside world. It is also thought that if such bacteria were to escape itwould act like smallpox or anthrax and ravage the land. However, laboratory-created organismsare not as competitive as pathogens. Davis and Roche sum it up in extremely laymen’s terms,”no matter how much Frostban you dump on a field, it’s not going to spread” (70).
In factFrostbran, developed by Steven Lindow at the University of California, Berkeley, was sprayed ona test field in 1987 and was proven by a RAC committee to be completely harmless (Thompson104). Fear of the unknown has slowed the progress of many scientific discoveries in the past. The thought of man flying or stepping on the moon did not come easy to the average citizens ofthe world. But the fact remains, they were accepted and are now an everyday occurrence in ourlives. Genetic engineering too is in its period of fear and misunderstanding, but like every greatdiscovery in history, it will enjoy its time of realization and come into full use in society. Theworld is on the brink of the most exciting step into human evolution ever, and throughknowledge and exploration, should welcome it and its possibilities with open arms.
Works Cited Clarke, Bryan C. Genetic Engineering. Microsoft (R) Encarta. Microsoft Corporation, Funk ; Wagnalls Corporation, 1994.Davis, Bernard, and Lissa Roche.
“Sorcerer’s Apprentice or Handmaidento Humanity.” USA TODAY: The Magazine of the American Scene GUSA 118Nov 1989: 68-70.Lewin, Seymour Z. Nucleic Acids.
Microsoft (R) Encarta. MicrosoftCorporation, Funk ; Wagnalls Corporation, 1994.Stableford, Brian. Future Man.
New York: Crown Publishers, Inc., 1984.Thompson, Dick.
“The Most Hated Man in Science.” Time 23 Dec 4 1989:102-104