It would be helpful to discuss these theoretical concepts because there could be significant practical and existential implications.
The Global Brain (GB) is an emergent world-wide entity of distributed intelligence, facilitated by communication and the meaningful interconnections between millions of humans via technology (such as the internet).
For my purposes I take it to mean the expressive integration of all (or the majority) of human brains through technology and communication, a Metasystem Transition from the human brain to a global (Earth) brain. The GB is truly global not only in geographical terms but also in function.
It has been suggested that the GB has clear analogies with the human brain. For example, the basic unit of the human brain (HB) is the neuron, whereas the basic unit of the GB is the human brain. Whilst the HB is space-restricted within our cranium, the GB is constrained within this planet. The HB contains several regions that have specific functions themselves, but are also connected to the whole (e.g. occipital cortex for vision, temporal cortex for auditory function, thalamus etc.). The GB contains several regions that have specific functions themselves, but are connected to the whole (e.g. search engines, governments, etc.).
Some specific analogies are:
1. The Broca’s area in the inferior frontal gyrus, associated with speech. This could be the equivalent of, say, Rubert Murdoch’s communication empire.
2. The motor cortex is the equivalent of the world-wide railway system.
3. The sensory system in the brain is the equivalent of all digital sensors, CCTV network, internet uploading facilities etc.
If we accept that the GB will eventually become fully operational (and this may happen within the next 40-50 years), then there could be severe repercussions on human evolution. Apart from the fact that we could be able to change our genetic make-up using technology (through synthetic biology or nanotechnology for example) there could be new evolutionary pressures that can help extend human lifespan to an indefinite degree.
Empirically, we find that there could be a basic underlying law that allows cortical neurons (the most relevant in my analogy) the same general lifespan as their human host. As natural laws are universal, I would expect the same law to operate in similar metasystems, i.e. in my analogy with humans being the basic operating units of the GB. In that case, I ask:
If, there is an axiom positing that individual units (neurons) within a brain must live as long as the brain itself, i.e. 100-120 years, then, the individual units (human brains and, therefore, whole humans) within a GB must live as long as the GB itself, i.e. indefinitely.
Humans will become deeply integrated and embedded into the GB’s virtual and real structures, that it may make more sense from the allocation of resources point of view, to maintain existing humans indefinitely, rather than eliminate them through ageing and create new ones, who would then need extra resources in order to re-integrate themselves into the GB. The net result will be that humans will start experiencing an unprecedented prolongation of their lifespan, during a process whereby the GB evolves to higher levels of complexity at a low thermodynamical cost.
It is known that that new neurons are formed during adulthood, at least in certain parts of the brain. This would be the equivalent of new babies being born to replace any human losses within the GB. However, the majority of cortical neurons are maintained in good operating condition and remain the same entities throughout life, instead of actively being replaced every few weeks (as in the case of, say, skin or blood cells).
According to some predictions, humans will increasingly embed themselves within this global brain by way of highly sophisticated digital interfaces (first examples are iphones) that can anticipate the subject’s wishes, preferences, habits etc. Eventually, there could be suitable technology that can allow direct brain to computer (GB) communication. If this is the case, I would expect that it will cost more in energy terms to replace a human brain (through creating a new one via the conventional lines) rather than maintain the existing one.
Research shows that new neurons that are not well integrated into the brain die prematurely. The same phenomenon could be true with humans: in order to survive a human brain must entirely integrate itself into the structure of the GB.
When fully operational, the GB must rely on its individual constituents i.e. individual human brains interconnected through technology. Without human input, the GB cannot exist. Furthermore, it cannot exist without technology. This is the same as in the human brain: a neuron contributes to the whole, but without suitable connections the neuron does not survive.
There is no magic involved. The sequence of events will happen naturally, based on natural laws. Human brains as individual units of the GB, will be subjected to increased pressures in order to survive longer. This is not a teleological argument. The GB does not have any intent or purpose. It is just an instrument of nature, forming part of the general direction of evolution: from simple to complex. And it is not a matter of living longer as a result of just using Facebook. It is a matter of a total, purposeful commitment to embed oneself into the GB and increase meaningful input of cognitive information of sufficient magnitude into one’s own brain. This will cause epigenetic changes, through a mechanism I describe elsewhere, that will repair and maintain somatic cells and reduce their risk of dying through ageing.