The term “biological immortality” doesn’t mean what you may think – it doesn’t mean living forever, but merely “the absence of a sustained increase in rate of mortality as a function of chronological age.” That is, you’ve reached biological immortality if your “personal death odds” – your chance of dying during a given random day, month or year — has stopped increasing.
This can be a pretty depressing sort of “immortality” – after all, if you have a 90% chance of dying on any random day, do you really care that this number isn’t increasing day after day? You’re almost sure to die pretty soon anyway!
But biological immortality is an important concept in aging research, even so. For instance, two of our speakers at the upcoming Humanity+ @ CalTech conference (Dec 4/5 – register today if you haven’t already!!) have dramatically different understandings regarding the importance of biological immortality, and this ties in closely with their different approaches to the practical problem of ending agins
Professor Michael Rose from the University of California at Irvine suggests that humans and other animals generally reach a plateau of biological immortality after a certain age – after this point, they’re not really “aging” any more, as their personal death odds remains constant. He hypothesizes that by following appropriate practices such as a properly-defined “Paleolithic” diet and lifestyle, one can reach the immortality plateau earlier, thus stabilizing one’s personal death odds at a lower level, and having a longer expected healthy lifespan. Further, he suggests that via doing research combining experimental evolution on model organisms (such as fruit flies and mice), genomic data analysis and artificial intelligence, one may be able to figure out personalized medicines and other therapies that will help one reach the plateau even sooner. [Full disclosure: I am currently collaborating with Dr. Rose on research in this vein, via my company Biomind LLC’s relationship with his lab at the University of California, Irvine, and the firm Genescient Corp. that he co-founded. I’ll also briefly discuss my own role in the work at the upcoming conference.]
On the other hand, Dr. Aubrey de Grey from the SENS Foundation (SENS = Strategies for Engineering Negligible Senescence) is unsure that the biological immortality concept is all that relevant to human aging. Like many biologists, he suspects that the data apparently supporting an immortality plateau in humans can actually be explained via the heterogeneity of data regarding aging and death from different populations. This is a subtle statistical issue, but it has practical implications. Dr. de Grey suggests that a large percentage of aging is due to accumulated damage in the body, and he describes an impressive variety of methods for alleviating or preventing this damage.
If accumulated damage is the main culprit behind aging, then one would not expect to see an immortality plateau – naively, one would probably expect to see the individual’s personal death odds keep increasing, as damage accumulated. So de Grey’s focus on accumulated damage fits perfectly with his skepticism about the relevance of biological immortality to human aging.
In spite of their conceptual differences, the practical work the two researchers and their teams are pursuing is largely complementary. If de Grey comes up with methods for repairing damage to the body, this will be useful regardless of whether he is right regarding the centrality of accumulated damage or the irrelevance of biological immortality. And if Rose comes up with therapies to decrease the personal death odds of the individual, this will be helpful regardless of whether he’s right about the immortality plateau.
But still the issue of biological immortality is an important one. Is Rose or de Grey correct? I don’t expect either of these scientists to convince the other one during their intersection at the Humanity+ @ CalTech conference – but it will be interesting to hear their back-and-forth in the panel discussion at the end of the Saturday afternoon session on “Radically Increasing the Human Healthspan.” If you can make it to CalTech for the conference, there are still seats available – otherwise be sure to catch it via live streaming video at http://humanityplus.org.