Is there
Intelligent Life on the Earth
What Can we Conclude from the Above Graph:
- Increase in Relative EL exhibits a well defined pattern
over the last 200 million years
- Fastest growth was from 600--250 million years ago when species
first emerged on the land
- Mass extinctions clearly are important as they substantially
alter the rate of growth
- Unaltered rate would have produced current human level of EL
about 60 million years ago
- Continental rate is much higher than the oceanic rate
- Smooth extrapolation backwards from last few million years of
continental data suggests it takes 20 billion years for intelligence
to emerge
It seems likely than when terrestrial ecosystems developed, the flow
of nutrients to the oceans became impaired which served to suppress
that ecosystems growth rate over the rest of geologic time.
Factors that might contribute to rate of growth of intelligence:
- Temperature: Many species function/learn best in a constant
temperature environment. Large temperature variations are then not
conducive to learning (this applies mostly to reptiles)
- Time - clearly EL evolves slowly upwards with time. Doubling time
appears to be about 2 million years
- Biogenic Environmental Diversity --> the more diverse the ecosystem
the more competition for scarce resources (food) there is --> could be
strong environmental stimulus for growth of intelligence. Suppression
of diversity by environmental disaster, climate change, or nutrient
depletion would then reduce this growth
- Trophic Level is importan --> where you are in the food chain -->
does this favor growth in predator or prey?
- Adaptation: Species defense mechanisms are a signature of of
evolution of intelligence. For instance, Coral defends itself statically
but glue-secreting frogs have ingenious method for fending up predators.
- Metabolism: --> large metabolism of mammals demands larger brain and
hence establishes initial capacity for evolution of intelligence in mammals
But clearly the role of mass extinction is paramount and allows the
survivors to fill the newly opened ecological
niches
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___________________________________________________________________
The Electronic Universe Project
e-mail: nuts@moo.uoregon.edu
