Genes that control the timing of organ formation during development also control timing of aging and death, and provide evidence of a biological timing mechanism for aging, Yale researchers report in the journal Science.
"Although there is a large variation in lifespan from species to species, there are genetic aspects to the processes of development and aging," said Frank Slack, associate professor of Molecular, Cellular and Developmental Biology and senior author of the paper. "We used the simple, but genetically well-studied, C. elegans worm and found genes that are directly involved in determination of lifespan. Humans have genes that are nearly identical."
A microRNA and the developmental-timing gene it controls, lin-4 and lin-14, affect patterns of cellular development at very specific stages. . .
According to Slack, [there is] strong evidence of an "intrinsic biological clock" that runs for aging as well as for normal organ development.
"This microRNA is conserved in humans leading to the enticing idea of being able to beneficially affect the results of aging including diseases of aging," said Slack. Work is under way to identify other microRNAs regulators and genes they target, to determine where they function and whether they behave the same way in mice, and to see if they are altered in human diseases of aging.
Genetic therapy holds great promise for treating several serious health problems, as well as possibly stopping natural deterioration altogether. However, the current state of the art can also cause problems, including cancer. Eventually, with the use of advanced nanotechnology, scientists may be able to directly edit the DNA of living cells in the body.
But even without that level of sophistication, massively parallel scanning -- made possible with tools built by molecular manufacturing (MM) -- may enable the sorting of cells modified outside the body. The ability to inject only non-cancerous cells would make some kinds of genetic therapy much safer. Microsurgical techniques could allow the implantation of modified cells directly into the target tissues.
Health improvement and life extension do not depend on MM, but it certainly will make them accessible to more people. Any treatment that can be automated can be applied to any number of people at low cost; such efficient research will speed the development of cures for complex problems such as aging.
What about the common objections to radical life extension?
If everyone were healthy and lived a long time, we'd overpopulate the earth.
Once infant mortality is minimized, birth rate contributes far more to population than lifespan, because children grow up to have children of their own. But as people get healthier, richer, and better educated, they have fewer kids. The birth rate is already below the replacement level in several rich countries.
Overpopulation is a centuries-old problem. Traditionally, it's been solved by infanticide, plague, and vicious war. MM will allow us to develop far more sustainable lifestyles and figure out better solutions for living in greater numbers on and beyond the Earth.
Life extension is immoral and we should resist it.
Smallpox vaccination, anesthesia, and blood transfusions also were said to be immoral. Today it's obvious that that's crazy. No one wants to be sick, and life extension is a natural result of health extension. Anyone who visits the doctor is working to improve their health and often trying to increase their lifespan as well.
Death is a natural part of life and it shouldn't be shunned.
Since when does natural equate with good? Tooth decay is natural -- should dentistry be outlawed? Polio is natural -- should we ban the Sabin vaccine? Cholera is natural -- should we allow epidemics to rage unchallenged?
In response to these questions, which I posed in The Scientific Conquest of Death, TechNewsWorld's Sonia Arrison writes:
It is an entirely human response to try to fix problems that are harming people -- including death. Some 150,000 people die globally every day. In the U.S., it's about 200,000 a month (6,500 a day). Given these numbers, it does seem rather odd that we aren't demanding a solution now. Perhaps one reason is that we live in a culture of death -- a culture that has convinced us that death is natural, good, and impossible to fight against, so we shouldn't even try.
But we should try, and as this book shows, some very smart people are currently engaged in finding the solutions. In the Bible, people were said to have lived for upwards of 900 years, and it would be nice to get back to that kind of run on life. As Rabbi Neil Gillman once said, "There is nothing redemptive about death. Death is incoherent. Death is absurd."