The physical, biological infrastructure that supports our minds is hamped by any number of shortcomings beyond the simple fact of aging - but you have to accept that any system will age and wear. The trick will be repair that wear and damage sufficiently well, economically and often to ensure prevention of problems and infrastructural failure. Such failures are neither pleasant, nor pretty - we'd all like to avoid that fate if at all possible.
In effect, we're all riding around in cars, but without the services of car mechanics. The first wave of technologies to meaningfully impact the great limitation of aging will center around dramatic improvements in our ability to repair biochemical wear and tear - it will be the advent of mechanics in a world filled with failing automobiles. In comparison, attempts today to rework our mechanisms - our metabolism - to lead to a tougher, more efficient biological engine with a longer mean time to failure are unlikely to have anywhere near as much impact on the same timescale. It's a great deal easier to build a garage and staff to service automobiles than it is to build a shop of specialists capable of machining up new cars from near-scratch.
But in the longer term, with more decades of biotechnology under our belts, reworking our bodies right down to the genetic level becomes a very viable possibility. Early explorations are already underway:
The public and even many scientists are unaware of how close science is to making germ line engineering a reality, said Dr. Michael Rose, who studies the genetics of ageing at the University of California at Irvine and who was a speaker at the meeting. He said the meeting would bring public attention to "one of the most important questions for the human species: the extent to which it will direct its own evolution."
Today, obstacles to germ line engineering are practical, not theoretical. Scientists have the ability to add desired genes - snapping gene cassettes onto artificial chromosomes and injecting the chromosomes into newly fertilised eggs. Because every cell in the body is a descendant of that first fertilised egg, every cell would have a copy of the artificial chromosome once inserted.
Artificial chromosomes, even human artificial chromosomes, have already been created and patented, the scientists reported, and companies have sprung up to exploit the technology. Dr. Leroy Hood, chairman of the department of molecular biotechnology at the University of Washington in Seattle, said he has now developed a way to create an entire custom chromosome on a computer chip containing DNA.
If we have developed SENS or similar repair-based medical technologies to hold aging at bay, and we have a low-cost biotechnology base to work with, all sorts of limitations are open to removal. Vulnerability to viruses, genetic disease, the quirky, evolved weaknesses and imperfections of biology; with sufficient understanding, it's all open to modification and improvement. The focus on the germ line is something of a red herring, however: mature, future gene therapy will mean an ever-expanding array of upgrades, fixes, cures and modifications that you can choose for yourself as an adult.
But it would be a shame if we all missed out on that, aged to death because we didn't focus on accomplishing the defeat of age-related degeneration that is presently just arriving in the realm of the possible:
My point here is that widespread complacency will be an undoing for us all - it's a common failure mode for those who look towards a better future, but never manage to engineer it. Massive assignment of time and resources is required for the goal of healthy life extension in our lifetimes. Engineering this use of resources is a huge task in and of itself. But supporters become enthusiastic, overestimate the degree of progress and the number of people helping make a better future, and stop making their own contributions. That scenario repeated en mass would mean that no progress is made - that healthy life extension technologies will not become effective enough to reach actuarial escape velocity within our lifetimes. Thus, game over; oblivion or taking your chances with cryonics.