liberte@uiucdcs.UUCP (08/10/84)
#R:mhuxt:-22800:uiucdcs:45500004:000:4835
uiucdcs!liberte Aug 9 18:54:00 1984
/**** uiucdcs:net.origins / js2j@mhuxt / 4:33 pm Aug 6, 1984 ****/
Why insulin? It would seem much more useful to find out how likely
the simplest kind of life form would be. Maybe we could draw up a set of
specs for an Amino Acid Motorscooter. Hopefully we could get some help from
some people who know a lot more molecular biology than I do. (none)
...
/* ---------- */
I was considering posting my "bubble" theory of origins for a long time. I
am also not a molecular biologist, or even a biologist. We are not likely to
find one on the net, so lets approach this as programmers. {hack, hack}
But first, I want to address the motive. Indeed, it is difficult to
imagine the rare conjunction of events that led to the first, simplest
organism. Even an Amino Acid Motorscooter, whatever that is, many be
too much to start with. But suppose that the first "life form" would
not be recognized as life today, but could eventually lead to a more
obvious form of life. That is what the bubble theory postulates.
We start out with billions and billions of tiny bubbles (Sagan will like
this) swimming around in the primeval soup. Where did they come from? A
collection of naturally occuring amino acids with hydrocarbon chain tails
will naturally align themselves on a surface so that the hydrocarbon part is
away from water and the amino acid is towards the water (or vise versa - it
doesnt matter here since I dont know what I am talking about anyway). Then
this membrane of lipids, as they are called, may enclose a waterless, or
less watery, interior in a bubble (in some magic step I dont understand, but
I believe has been observed). Voila! Scrubbing bubbles.
Most of these bubbles will not do much of interest and will either pop or
dry up or just float around looking pretty (to another bubble that is). But
you see the possibilities. Bubbles may join one another and mix it up.
Bubbles may collect together in a colony or become enclosed in a
superbubble. More importantly, the lipid membrane surface with its amino
acids will have different properties depending on the amino acids, allowing
some materials to pass into the bubble and others to pass out.
Consequently, the membrane (memory-brain?) acts as a filter between the
inside and outside environments of the bubble, hence the scrubbing effect.
Now imagine that out of these billions of bubbles, some of them
have the property (determined by which kind of amino acids they have
on their surface and in their innards) that they can absorb material
from the outside environment. They will consequently grow and usually
break into little bubbles as they try. This is a form of reproduction
called budding actually practiced by the yeast. (We could call these budding
scrubbing bubbles, but lets not.)
After a long time, some fairly brainy, better bubbles are working away
eating other bubbles because everyone ate everything else. Perhaps as a
consequence of this cannibalism, and certainly due to the competition, new
methods will be "discovered/invented". The cooperation of bubbles in a
colony could easily lead to specialization of function by different bubbles
within the colony. This could lead to a form similar to the present day
"cell" with its internal, specialized organelles, but with a completely
different biochemistry.
How did the step up to RNA/DNA and coded protein production take place? I
havent thought too much about that, but let me take a stab at it. Assuming
that nucleic acids are produced by some process (perhaps ejected as waste
products by some class of bubble) and that they string themselves together
in any random order in the familiar double helix structure, then we have the
raw material for the protein production process. I guess I am also assuming
that nucleic acid chains will spontaneously split and replicate, albeit
messily unless within the controlled environment of modern cells.
The coding of amino acid chains in nucleic acid chains would be done by
default, i.e., certain amino acids would tend to associate with certain
groups of nucleic acids, not by the final coding scheme necessarily. The
resulting proteins would either be beneficial or detrimental to the life of
the bubble. I expect early attempts at this would usually make a mess of
things. So there has to be some incentive to keep trying. Perhaps the
nucleic acids initially act as catalysts in protein formation thus giving
the advantage to those bubbles with the audacity to play with nucleic acids.
Does adaciously playing with this bubble concept give me any advantage
in net.origins? Until next time...
"This is Marlin Perkins with Mutual of Omaha's Wild Bubbles."
Daniel LaLiberte (ihnp4!uiucdcs!liberte)
U of Illinois, Urbana-Champaign, Computer Science
{all absolutes are false -- including this one}