Matt Ridley
Author of Genome: The Autobiography of a Species in 23 Chapters
One of the most far-reaching developments will be the discovery of the genes that cause us to age. Once we understand those genes, we will be able to counteract them. Then we will slow down the aging process dramatically. My great-grandchildren might live to 150 and not look very old at the end of it.

The social and economic consequences will be striking. Careers would potentially go on forever, and there's no particular reason why people should retire. People would delay having children in order to keep their career and mating options open. If you could quite happily have your first child in your 50s or 60s, a lot of people would do that, and population growth would start to fall very rapidly.

Lee Silver
Professor, Department of Molecular Biology, Princeton University
Fifteen years ago, I would have put limits on what we would ever be able to do to alter our genes. Now I believe there are no limits—no technical limits anyway. Within the next half-century, and probably much sooner, we will have a complete understanding of what every gene does. We will also be able to repair individual genomes by replacing defective genes. This so-called germ-line genetic engineering is currently viewed with horror, but that will change as people realize that fixing the faulty gene that causes Huntington's disease in all future generations, for example, is a good thing. It's also hard to imagine forbidding people to give their children the gene that currently protects about 1% of the population from developing aids when infected with HIV. Where it gets trickier is when we figure out what are the naturally occurring genes that put some people at the upper end of the statistical bell curve for intelligence or talent of some kind. It's human nature to give your kids any advantage you can, and once this becomes theoretically possible, the pressure to allow it will become enormous. I suspect it won't be cheap, even in 50 years, but it might be on a par with buying a car, which means it will become widespread through the middle class, at least in rich countries like the U.S.

Ray Kurzweil
Inventor and author of The Age of Spiritual Machines
Within a quarter-century, we will have completed the reverse engineering of the human brain and will understand its principles of operation. We can then implement similar "biologically inspired" methods of information processing using far more powerful computational technology. This will combine our human strengths in pattern recognition and emotional and artistic intelligence with the speed, capacity and knowledge sharing of machines.

The emergence in the early 21st century of this new form of intelligence, one that can compete with and ultimately significantly exceed human intelligence, will have profound implications for all aspects of human endeavor, including the nature of work, learning, government, warfare, the arts and our concept of ourselves. Our biological intelligence is for all practical purposes fixed, whereas nonbiological intelligence is at least doubling in power every year, so by 2053, it will dominate.

French Anderson
Director, Gene Therapy Laboratories, University of Southern California
Few present-day medicines heal anything. We treat the body's symptoms while the body heals (or does not heal) itself. By 2053, there will be a gene-based treatment for essentially every disease. Cancer, heart disease, and other modern-day scourges will be vastly reduced. Aging and trauma will be the major causes of death, and society will need to adjust to a significant increase in the average life span.

Kary Mullis
Biochemist and inventor of the Polymerase Chain Reaction
It's not hard to imagine where we'll be in 50 years; you and I will probably be dead. But that doesn't mean things won't advance. You could conceivably start mapping DNA in babies shortly after they're born and then do RNA testing monthly. This could reveal all sorts of disease states. More important than the scientific questions though will be the moral, social and economic problems associated with having all this information. I suspect in 50 years we'll have figured out how to do this testing scientifically, but we'll still be arguing about whether we should be doing it. The tests will be much more complicated than current ones, but they'll be hellaciously more informative too.

Stanley Prusiner, M.D.
Professor of Biochemistry, University of California, San Francisco
When people who are 60 years old today ask me what they can expect from medical science for the rest of their lives, I tell them we have no idea because science moves so fast. What will things will be like in 50 years? Those very 60-year-olds may be here to see it. If people do start living that long, it won't be because their genes keep them going; it will be because medical science does.

Hamilton Smith
Nobel Laureate & Scientific Director, Institute for Biological Energy Alternatives
Fifty years from now, most everyone will have their total genomic sequence determined at birth, and we will have extensive catalogs of correlations of individual genotypes (or haplotypes) with disease susceptibilities, drug responses, talents, and abilities in so far as they are determined by inheritance. Laws will be enacted to protect privacy and many, if not most people, will not want to know such information except in limited circumstances.  On a bright note, most mental diseases will be fully understood at the genetic and biochemical level, and most will be fully treatable.  Mental disease will be largely conquered.  In general, I am optimistic that genetic information will be used for the good.

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