Complexification of life [was: Selfishness]

From: Robert Bradbury (
Date: Sun Jan 23 2000 - 15:26:55 MST

On Sat, 22 Jan 2000, Joe E. Dees wrote:

> I believe Robert Owen wrote:
> >
> > The basic question asked is: why is their not nothing but unicellular life
> > on earth? Why are we not all bacteria?
> >
> > What needs to be explained, in this view, is what would cause quint-
> > essentially successful unicellular organisms to form communities and
> > eventually a differentiation of labor in the development of multicellular
> > organisms such as ourselves. Whatever the cause, the effect obviously
> > had survival value.

Precisely. Forming multicellular organisms changed the scale at
which you could operate, therefore opening up new ecological niches.
Consider the race to "get big" in trees. The higher you go, the
more sun you get. Now, the transition to complex cells was driven
mostly likely by the difficulty of transfering large gene complexes
of naked DNA between bacteria. Better for one bacteria to "get big"
and engulf another one in its entirety (leading to mitochondria
and chloroplasts). The problem is that once you are "big" you
have to develop better partitioning systems or active transport
to keep the diffusion of molecules in a very large space from
slowing down your growth rate. Even then the added complexity
gives you headaches (bacteria replicate in an hour or less, eukaryotic
cells take 18-24 hours).

I think calling all of this "cooperation" may be stretching it
a little. We would have to nit pick on the difference between
cooperation and symbiosis. Particularly when the symbiosis
may be required for the survival of both "organisms", while
cooperation perhaps is not.

Generally, I would agree that the rise of social cooperation has
some similarities (cooperation between people changes the scale at
which you can "operate", opening up new niches in which you can survive).


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