[ExI] Maximum biological lifespan

Anders anders at aleph.se
Fri Aug 12 20:48:35 UTC 2016

On 2016-08-12 13:10, David Lubkin wrote:
> It seems to me there could be a planet where there only has ever been 
> one organism of one species. That "evolved" not through our 
> competitive pressures but through that one organism's adaptation to 
> external environmental pressures: climate, weather, radiation, seismic 
> events, bombardment, etc.
> Or, the biosphere had an evolution much like ours until a combination 
> of external events killed off enough other life for one species to 
> supplant all others. Say one fungus that covered the whole planet, 
> that needed no other species, that then potentially develops further 
> as in the previous paragraph. That can be considered a unitary 
> metabolism.

These are low probability cases. The first one is like the creationist 
canard, having to self-organize out of a random assembly of chemicals 
into a perfectly stable and functional form. Sure, in an infinite 
universe this happens at some rate.

The second one is more likely, but it is not stable. Cells mutate and 
diverge genetically, and before you know it symmetry-breaking gives rise 
to speciation. You need somewhat peculiar conditions to keep it from 
splitting into subspecies.

Just consider Tom Ray's classic experiment with the Tierra simulator, 
where overnight a single hand-written replicator turned into an ecology 
including other replicators, parasites and hyperparasites. Real life is 
way more adaptable than that code.

Dr Anders Sandberg
Future of Humanity Institute
Oxford Martin School
Oxford University

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