Our Future Bodies

"If we could make better human beings by knowing how to add genes, why shouldn't we?"

—James Watson, biologist

"We will be sorely tempted to engineer our kids, but it's a temptation that we need to resist."

—Bill McKibben, author

An example of a microtiter plate and multichannel pipetter, used to process DNA samples for a sequencing machine.

© AMNH / Denis Finnin

Is genetic engineering in our future?
Your DNA contains the genetic instructions for building and maintaining every cell in your body. Scientists have deciphered the entire human genome—and are developing revolutionary technologies that may enable them to alter many aspects of our bodies and behavior. In the future, you could be making decisions about whether to change your genes or select those of your children.

Modifying one person is not evolution: evolution naturally happens to populations, not individuals. But if new genes were inserted into thousands of people—and these genes were inherited by future generations—we might radically speed up evolutionary change. Today genetic engineering in the form of gene therapy has had limited success in addressing some diseases.

Looking ahead, though, advocates say that genetic engineering offers the potential to enhance your family's health, intelligence, memory, appearance and extend life span. Critics note that genetically modifying humans raises both practical and ethical concerns.

Is Gene Therapy Safe?
For Ashanti De Silva, who was born with a genetic disorder that prevents her body from producing a crucial protein, gene therapy saved her life. Doctors inserted cells containing the missing gene, enabling her to attend school and live a normal life. But critics of the technology say it's not always safe, pointing to the death of a 19-year-old college student who underwent gene therapy trials. Advocates say techniques have improved.

Is Gene Therapy Fair?
Genetic engineering raises ethical questions. Advocates argue that as DNA enhancements become cheaper, the benefits will spread to everyone. Critics worry that the technology would be limited to the few who can afford it. And who would decide how and to whom this technology is applied? What are the chances that any positive benefits would be lost due to a misguided or ill-intentioned use of this technology?

Could We Stop It If We Tried?
Some argue that we should ban human enhancements, while permitting research on curing genetic illnesses. But such a distinction is not clear. A treatment for restoring memory in Alzheimer's patients, for example, could also be used to improve the memory of healthy people.

From Mice to Men?
Over 100 individual genes have been found that extend life span in mice and other animals—and the same genes appear in humans. In addition, scientists have inserted genes in mice that increase muscle growth and reduce fat, without a change in diet or exercise. Some think humans won't be far behind.

• Our Future Bodies
• Our Future Environment
• Our Future Universe