THE HUMAN GENOME PROJECT.




a. What has been achieved?

b. Not in Our Genes: Richard Lewontin.




WHAT HAS BEEN ACHIEVED?



Human Genome Project also called HUMAN GENOME INITIATIVE, is an international scientific research effort to analyze and identify the human DNA in terms of the genetic code. The project began in the United States in 1990 under the sponsorship of the U.S. Department of Energy and the National Institutes of Health and was hoped to be completed in 15 years. Essentially, it has been completed in the year 2001. The project's ultimate goal was to map the chromosomal location of every human gene and to determine each gene's precise chemical structure in order to elucidate its function.

Two types of maps have been and are being constructed: genetic linkage maps and physical maps. A genetic linkage map provides the relative location of genes and other markers on the basis of how frequently genes on the same chromosome are separated by recombination. The more frequently they remain linked the closer they are to each other on the chromosome. Physical maps locate genes in relation to known nucleotide sequences that act as landmarks along the length of a chromosome. Determining the precise order of the nucleotide sequences has been the most technically challenging part of the project.

In addition to the human genome, the genetic make-up other organisms were also sequenced partly to help the progress of the human genome, and partly to assess the similarities of gene sequences in evolutionarily unrelated organisms. The mouse, a nematode worm, the fruit fly, a yeast, and the E. coli were studied and their genome mapped. Surprisingly, the counterparts of many genes found in simple organisms can also be also found in our genome.

The human genome projects has been undertaken in a number of countries including Japan, the United Kingdom, Italy, France, and Russia. These all have been coordinated with the American effort through the Human Genome Organization. The Human Genome Project has a great deal of practical potential. The information obtained will be of interest for researchers in human biology and medicine and will provide better understanding about many genetic disorders and their treatments.

Partially modified from "Human Genome Project" Encyclopædia Britannica Online. Copyright © 1994-2001 Encyclopædia Britannica, Inc.




NOT IN OUR GENES: RICHARD LEWONTIN.



The purpose of this section is to examine the motivation behind the human genome project. It seems that many people got carried away by the promises of the project thinking that by knowing the genes we know the organism. This is far from being so. It has been proven by many researchers that genetic determinisim has no real foundation in experience. Of course, genes do contribute to the development and maintenance of each and every living organisms but there are other factors as well. Notably, the organism itself, the environment, and a number of random factors also contribute to the outcome that we encounter. We may think of such contributions from the various factors as parts or components of a larger process and then come to a rather mechanistic conclusion about life. These factors do not simply make contributions in an additive manner but also interact in ways which are often not independent from each other.

Richard Lewontin in a book Human Diversity, published in 1982 in the Scientific American Library series, in chapter six presents a powerful example of interdependence between the genotype and the environment. The example refers to the two variants of the enzyme glucose-6-phosphate dehydrogenase. Measuring the population distribution of enzyme activity at two different substrate concentrations we find that the distribution is similar in one case and completely different in another. In other words, the distribution of genetic effect in enzyme activity has been changed by simply changing the environmental conditions. This and many other examples indicate that the contribution of genes to the phenotype is interactive and not determinant. Lewontin further explains the idea of complex interactions between gene, organism and environment in a delightful book The Triple Helix, Harvard University Press, 2000. The book is highly recommended.

Arthur Jensen in an article that appeared in the Harvard Educational Review in 1969 How Much Can We Boost IQ and Scholastic Achievement? maintained that the differences in intelligence between races as it is measured by IQ tests is genetically determined, and comes up in favor of whites. In practical terms this was a highly racist statement, and it did a great deal of damage because the Nixon administration being in position at the time found in it an good enough excuse for cutting funds previously supporting welfare and education. There was a strong outcry against Jensen among scientists criticizing both his data and his conclusions. That was the time when Richard Lewontin, Steven Rose and Leon Kamin published the book Not In Our Genes in response to Jensen’s report, and provided a much more balanced view.

And then it happened again. Richard Herrnstein and Charles Murray brought to light the book The Bell Curve. Intelligence and Class Structure in American Life, the Free Press, 1994. The authors followed pretty much the same line of thought in genetic determinism as Jensen did. The retaliation was practically immediate. In the January issue of Scientific American, 1995, Tim Beardsly wrote a powerful essay against the contents of the book with the title for Whom the Bell Really Tolls. A month later in the same periodical Leon Kamin briefly but sharply debunked The Bell Curve. Similarly, Stephen J. Gould in Natural History’s February issue of 1995, in This View of Life, under the title Ghosts of Bell Curves Past strongly objected to the ideas and conclusions of Herrstein and Murray saying: “IQ is a helpful device for identifying children in need of aid, not a dictate of inevitable biology.”

The real scope of the Human Genome Project is not to overemphasize the impact of genes on human life, but to come closer to understand the connection between gene products, disease and treatment. To discriminate against people based on their genetic endowment is clearly an unfounded and intolerable abuse.


Further resource: R. Lewontin, It Ain’t Necessarily So. The Dream of the Human Genome and Other Illusions. New York Review Books, 2000.

 

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