Basic life extension occurs simply through good medicine, keeping a healthy personal environment, antioxidant supplements, broad spectrum antibiotics, gene therapy and the ability to grow new organs from cloned cells. It allows bioids to live up to their natural lifespan (around 120 years in baseline humans). This level is achievable by even low-technological societies such as the Information Age Earth.
More advanced life extension extends the maximum biological lifespan. The lifespan is determined due to genetic factors, and to extend it either total gene therapy (adding genes to every cell in the body, a technique requiring mature nanotechnology), germline genetic engineering before birth or other profound genetic modifications are needed. Early methods could double or triple the lifespan, and for bioid clades with sufficiently well mapped biology it is now possible to totally remove the aging process beyond maturation.
Even when the aging process has been regulated the organism is not immune to wear and tear. Joints, teeth, eye lenses and some other tissues wear out and have to be replaced. The brain needs replenishing the neuron pool. Cancers have to be continually removed. The immune system and other dynamical systems in the body will need occasional retunings. Often this is done through the nanotechnological medical support systems ("nanoimmune systems") that are ubiquitous in well developed regions, although rejuvenation treatments are also common.
The main problem is mental aging. Even when the body and brain is working efficiently, the psychology of the profoundly old tends to change. The biologically caused decline in mental plasticity can be treated using neurotrophics, but there is a problematic trade-off between too much and too little: too much new plasticity makes the person adaptable, but also means that old memories will gradually fade and the personality drift over time. Too little plasticity will mean the person gets trapped in the same mental patterns and has an ever harder time adapting to anything new, ending up as a habitual "struldbrug".
There are many different solutions. One is simply acceptance of constant identity drift, a fairly common view especially in the NoCoZo that has been famously expressed in the (continuing) documentary My Lives by Anato Kau Kommo. Another is rejuvenation treatments, essentially adolescences marking the end of one way of living and the start of a new. This is perhaps the most common method. A third approach involves mental disciplines (or advanced neuronics) to sustain and maintain core memories and personality while discarding irrelevant information over time. Especially citizens of Keter and the Negentropy Alliance favors this. A fourth form, Template Rejuvenation, uses brain scanning methods to store personality and memories before rejuvenation treatments and then mildly re-inprints them afterwards through continuity implants. This tends to be expensive, and is mainly used by a few clades who for various reasons do not opt for full virtualisation.
It should be noted that biological life extension is fundamentally limited due to the finitude of bionts. Beside the always finite chance of being killed in an accident, the total repertoire of experience and thought of a biont brain is finite and will eventually be filled or forced to repeat itself in an eternal return. Although this is a minor problem due to the extreme timescales involved, any true form of indefinite lifespan will by necessity involve a gradual extension of the being through new biology, nanotechnology, cyborgisation or virtualisation.
- Immortality - Text by M. Alan Kazlev
While literal physical immortality remains a contentious point in a universe that, although vast, is still finite, the wonders of modern medical nano mean that all citizens of the Civilized Galaxy, to say nothing of the higher toposophic ai, are potentially immortal; at least on angelnetted worlds. See also life-extension, afterlife.
- Lazarus Longidae - Text by Steve Bowers and Michael Capriola
Tweak clade known to live for thousands of years. Named after a fictional character created by the Information Age novelist Robert A. Heinlein, who told Long's story as a series of memoirs. The Lazarus Longidae clade write all their long term memories down in very small thin leaved notebooks, use tiny shorthand ideogrammatic writing, and keep the notebooks in hundreds of small pockets in their overalls, moving all the notebooks around sequentially each time they fill one and throwing the oldest one away.
- Technological Afterlife
- Universal Immortalism - Text by M. Alan Kazlev after R. Michael Perry in Anders Sandberg's Transhuman Terminology
The belief that death can be overcome completely, even for people already dead (including bringing back those "dead" who were not placed into biostasis) through a rational, scientific approach. Although popular with some religions and eschatologists, and even a few cliologists, it is not a widely held memeticity.