The emergence of an
ocean-worthy cellular Cassius would have opened a huge volume of
potential habitat to the early life forms. You might say it produced
the fourth explosion of new life forms that expanded and filled
the waters of the early Earth.
During the first Fred/Roscoe explosion there
may only have been hundreds or thousands of organisms on the entire
Earth, since they could only survive in a few shoreline pools with
exactly the right conditions. In fact, because it was so difficult
for the individual molecules to diffuse simultaneously into the same
puddle, it's possible that they never expanded outside their
original neighborhood.
The Caleb and early Cassius explosions would
have kicked the populations up a notch, since
they could thrive in more types of
puddles, and since they could bring along most of what
they needed in a single package.
However, once Cassius was freed from the
occasional specialized puddles, it could
have potentially increased its population
to exponential levels. Having just
one cellular Cassius per liter of
ocean would have meant there were
1021 individuals floating
around (or about a sextillion cells).
With such a huge pool of different Cassius
organisms, the pace of evolution would have increased enormously,
simply because there were many more organisms in which improvements
could appear. Different versions of Cassius in different habitats
would have evolved different features or different metabolic strategies,
and the era of plain old Darwinian selection would be at hand.
Evolutionary Speed
How long would it have taken from the first
Fred and Sofia combination to the first cells capable of replication
and metabolism?
If we are willing to lower our definition
of life to a bare minimum, it may not have taken long at all, at
least in a geological sense.
The ratio of carbon isotopes in extremely
old rocks dating from 3.85 billion years ago seems to indicate that
life may have already evolved by that time.
Advanced versions of Cassius would be already
be capable of performing metabolism which would change the carbon
isotope ratio, and it's possible that the entire progression
from Fred to Cassius may have happened extremely quickly-- in
tens of millions of years or less. There are quite a few steps to
the transformation, but none of them are sufficiently improbable
that they would have taken billions of years.
Multiple Waves
Once an evolving, cellular version of Cassius
was on the scene, there would have been many successive waves of
more efficient versions of Cassius, each expanding geographically
into a wide range of habitats, and becoming the dominant life form,
at least until the next Cassius came along.
As Cassius and its progeny gradually developed
more metabolic enzymes and started to eat their surroundings, they
would have digested the last of the primordial soup and converted
it to biomass. With all organic compounds now created by enzymes,
the last of the older, racemic chemistry would have disappeared from
all but the most isolated nooks and crannies of Earth.
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