[extropy-chat] Easter Island not a human-created disaster?

Keith Henson hkhenson at rogers.com
Tue Jan 9 06:35:29 UTC 2007

At 05:38 PM 1/8/2007 +0000, BillK wrote:


>Jared Diamond made Easter Island the main plank in his book about
>collapsing societies. So if it is removed, then his case is certainly
>much weaker.

The strong point Hunt makes is that the settlement happened much later, 
around 1200 AD and that rats kept the palm tree from regenerating.

And he makes a much weaker case that the population only reached about 3000 
before being somehow limited.

I buy into his first point.  Assuming 20 people settled and a 3 % growth 
rate that's a bit over 4 doublings per century.  20,000 is 10 exp 3 times 
this much or 2 exp 10.  So by 1450 there could have been 20,000.  I ran 
this calculation a long time ago and could not figure out how the 
population had grown so slowly.  And I agree with him about the rats.

He doesn't say what limited the population.  Azar Gat makes the case that 
wars over resources generally limit historical hunter gatherer and 
primitive farming populations.

The only big question is was there a population overshoot and decline, even 
an undershoot.  That depends to a considerable extent on the maximum 
potential of the local ecosystem and if over exploiting it reduced its 
ability to support human population leading to a crash.  Such models as I 
have seen indicate that's rather possible, in fact, the models suggest that 
the population had recovered from a low of about half what was there when 
Europeans arrived.

There is no doubt that European contact was a disaster for the natives, but 
that does not have anything to do with the deforestation disaster which 
Hunt places before contact.

None of these relatively minor details undermines Diamond's work.

>The effect of climate changes (drought, floods, plagues, disease,
>etc.) on early human societies is a hidden history that is only now
>gradually being revealed. Ancient history recorded wars, revolutions,
>invasions, as written by the victors, recording their achievements.
>But they rarely commented on the environmental factors that often
>drove people to these desperate measures, or weakened the losing
>opponents in the war.
>In some cases the society just disappeared..

True.  A combination of bad weather and an inappropriate human response to 
war was lethal over a huge area in the American Southwest.  Go here:


and search for "corn farmer."

Incidentally, one early human caused ecological disaster was in 
Greece.  They mitigated it with boats.  Virtually the same thing wiped out 
the Myans.

Keith Henson

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