Genetic Engineers

Gregor Mendel, an Austrian monk, documented the basic principles of genetics in the 1860s following years of experiments breeding varieties of garden peas to demonstrate dominant and recessive traits. His work paved the way for later scientists, such as Thomas Hunt Morgan, who—fifty years later—showed that genes are located on the chromosomes present in every cell. These genes provide the blueprint for every living organism, whether animal or plant, and when these genes fail to copy themselves correctly during reproduction, genetic mutations may occur, which can cause illness, deformity, or other unexpected traits. 

The next major era in genetics began in the 1950s when James Watson and Francis Crick discovered the double helix structure of deoxyribonucleic acid (DNA), the material that contains the genetic information for living organisms. Building on this discovery, scientists sought to better understand DNA and genetics, taking a major step forward with the development of recombinant DNA techniques. These techniques allowed researchers to combine the genetic material from separate organisms to form new, unique combinations of genes using restriction enzymes. These enzymes allow scientists to separate DNA pieces and join together pieces from different sources to produce cells with specific traits which could then be cloned to spread those traits for disease-resistant plants, beneficial bacteria, and other purposes.

The Human Genome Project, launched by the United States government in 1990, further revolutionized genetics by mapping the entire sequence of the human genome. Completed in 2005, this cataloging of all the genetic material in human beings, which is still being studied, has given scientists the basis for many potential advances in medicine and other therapies to fight disease, prevent birth defects, and diminish the effects of aging.

Other major developments in genetic engineering and research include:

• the cloning of the first animal gene (1973)
• the establishment of the first genetic engineering company (Genetech, 1976)
• the development of rapid DNA sequencing methods (1975–1977)
• the discovery that genes had many interruptions in their structure (known as introns), which changed the way scientists perceived the structure of hereditary information, or a genome (1977)
• the ruling by the U.S. Supreme Court that genetically altered organisms could be patented, which prompted a petroleum company to patent an oil-eating microorganism (1980)
• the development of the first transgenic animals (mice and fruit flies, 1981–1982)
• the approval by the U.S. Food and Drug Administration (FDA) of the first genetically engineered drug, humulin, a form of human insulin produced by bacteria (1982)
• the mapping of the first genetic disease (Huntington’s disease, 1983)
• the completion of the first field tests of genetically engineered plants (tobacco, 1986)
• the approval by the FDA of the first genetically engineered vaccine for humans (for hepatitis B, 1986)
• the completion of the first field tests of genetically engineered crops (tobacco and tomato, 1987)
• the approval by the FDA of the first genetically engineered food, chymosin, which is used in cheese production (1990)
• the approval by the FDA of genetically engineered Bovine Growth Hormone, a drug that is designed to increase milk production in cows (1993)
• the cloning of Dolly the sheep (1996)
• the first human chromosome is sequenced (1999)
• the first gene-targeted drug therapy is approved (2001)
• the creation of the world’s first synthetic life form (2010)
• the discovery of the CRISPR Genome Engineering Tool (2012)
• the approval of the first human trials for CRISPR (2018)