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Where Personal Identity Starts

At a basic level, personal identity is formed through our thoughts, understandings, habits, and memories of experience. The conscious dimension of personality defines who we are. But there is another level of reality beneath this, equally important. That would be our genetic endowment.

Each human being is genetically unique. As living creatures, our bodies are comprised of cells infused with a unique genetic structure and code. There are three billion elements in the human genome, which is the picture of a complete gene. While many are common to other human beings, animals, and plants, some elements or combinations in the code are found only in the genes of a particular individual. From the entire genetic package comes a person’s physical type - his or her sex, hair color, bone structure, disposition to get cancer, and other characteristics of the human body. Genes are the building block of life.

We are living in a time of unusual discoveries in this area. In the mid 20th century, James Watson and Francis Crick, along with others, discovered the structure of nucleic acid (DNA and RNA) in the so-called “double helix”. Years later, teams of scientists including Watson mapped the human genome. This was a massive project aided by computers. But the work is now done. We have a general understanding of the composition of genes; and that opens up the opportunity for a wealth of other information about our genetic endowment and the consequences of that endowment, especially in the medical field.

New businesses have arisen to exploit the new knowledge. With respect to personal identity, some of these businesses are:

(1) a service called CODEme from Decode Genetics, an Icelandic firm. Clients scrape cell tissue from the inside of their cheeks and send this sample along with a check for $985 to Decode Genetics. In return, they receive information about their personal genetic endowment that includes disease risk, hair and eye color, and ancestral origins.

(2) a similar service from a firm called 23andMe that uses a smaller, custom-made analytic device. This is a company, financed by Google, which was founded by Linda Avey, a biotechnology executive, and Ann Wojcicki, who is married to Google’s cofounder, Sergey Brin. The name of the company refers to the 23 pairs of chromosomes in the human genome.

(3) A third firm, Navigenics, of Redwood Shores, California, will focus upon genes that cause disease.

The product offered by these firms makes use of devices known as SNP chips which focus on the parts of the genome that are responsible for differences between human beings. It cuts costs by ignoring most of the genetic structure in favor of analyzing the major points of difference, known as the “single nucleotide polymorphism” or SNIP, within the DNA structure.

The analysis done by such companies can assess the risk to individuals from diseases such as cancer, diabetes, and heart disease. It can determine a person’s likelihood of having a certain color of eyes or hair, skin color, or freckled skin. Additionally, this analysis can trace a person’s ancestry through the Y-chromosome back 50,000 years and through mitochondrial DNA in the genes of women. DNA analysis gives a record of past migrations as the human species left Africa and settled various parts of the earth.

There is also, however, concern that the genetic information will be misused. Insurance companies may refuse to cover high-risk individuals or people who review their own DNA record may worry about factors beyond their control. So the future-telling capability which genetic analysis gives humanity may have negative as well as positive consequences.

However, as a tool for understanding ourselves at the deepest physical level, the new techniques of DNA analysis offer an unprecedented opportunity.

Source: “$1,000 buys a genetic glimpse into your past, future” by Nicholas Wade, New York Times. Reprinted in Star Tribune, November 17, 2007, p. A3.


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