[ 26/July/21 ]
What exactly does the question ask?
Lifespan is the length of time a person actually functions (lives).
Does the question mean – of those who have been reliably measured in the recent past? – Then about 133 years.
Does the question mean – of those currently alive? – Then probably somewhat less than that.
Does the question mean – using the best technology currently available today, then how long might an individual alive today live? – Then the answer is probably of the order of 150 years.
If however, one takes the much more interesting question, which is, if one is taking a deep systems view of existence, of the evolution of life, of the evolution of systems of understanding, and of the evolution of technology; and one looks at those trends over time; then what is the projected maximum life span of some subsets of individuals currently alive? – Then the answer is probably some approximation to indefinite.
I write the latter answer as an autistic spectrum geek who completed undergraduate biochemistry in 1974, and who understood enough about systems even back then to see that age related loss of function is not a general characteristic of cellular life, but it is a characteristic of most complex cellular life. Understanding exactly why that is so is far more than a post like this can convey, but the necessary corollary of that was, that the default mode for cellular life is indefinite (if you think about it, there is an unbroken chain of cellular life going back from you to the first cell somewhat over 3 billion years ago – you resulted from an egg from your mother merging with a sperm from your father, as did they, as did their parents, …. , lots of cell divisions and mergers, and all cellular life), and that once we understand it at a sufficient level of detail, then indefinite life extension was possible.
The last great technical roadblock to building such an understanding was being able to determine protein structure from RNA sequence. Alpha-fold2 has essentially solved that problem (last year – at least with sufficient accuracy to allow significant work towards indefinite life extension for all who want it).
Eliminating the risk of death from biological aging does not eliminate all risks of death, and it is a necessary step towards indefinite life extension.
The next greatest risk of death comes from the activities of other humans. That needs to be substantially reduced. That requires most people understanding several major errors in commonly believed dogma.
Perhaps most important is the idea that evolution is all about competition.
Certainly competition is often a major factor in biological systems, but if one actually does the math and builds a systems understanding of the emergence of complexity, then it is clearly true that all new levels of complexity are the result of new levels of cooperation, and stabilizing cooperative systems requires emerging ecosystems of cheat detection and removal systems – nothing simple there.
As human beings are the most complex thing we currently know of in the galaxy, then it is necessarily true that we are the most cooperative things in the galaxy; and our survival is actually predicated on us recognizing that it is cooperation (not competition) that is fundamental to our emergence and our long term survival. Nothing wrong with a bit of competition, provided that it is firmly and securely contained within a cooperative base. Any unrestrained competition is necessarily destructive of complexity – that is proven beyond any shadow of reasonable doubt.
So most of modern public political and economic dogma is necessarily false; and it is accurate to describe most of the current economic, political, legal and educational institutions as cheating strategies on the cooperative that is human society (however many great and cooperative individuals there are contained within them).
Once this is clearly recognized, and people also recognize that any and all centralized systems are high risk; and that, in complex systems, security necessarily requires diversity and redundancy at all levels; then some reasonable approximation to reliable long term security becomes possible.
Such security cannot be achieved by any sort of central control; it must emerge from cooperation between multiple levels, classes and sets of diverse independent agents. World wide cooperation is required, one world government is not (it is actually the antithesis of ).
Being extremely clear about that distinction is critical to long term survival – all levels.