Re: Biogenesis question

Hi Jim

> That leads me to an admittedly not-too-well-articulated question: Do
> you know of any line of reasoning that considers biogenesis for
> creature-kind a transition from veggie life to animal life, as opposed
> to inanimate to animate?

I'm not sure I really understand your question here.
In the science perspective, what people speculate
(here there is really little proof but some reasonable
conjecture) is that something like blue-green algae was
first. There are some stromatolites deposits in Australia
(as I recall) that resemble similar things we see today and
are about 2.5 Gyr old. As far as I know, that is the
most solid piece of evidence we have of life that far back.

Naturally, the problem here is that single celled organisms
would be difficult to fossilize and even more difficult
to find even if they were.

However, there are the banded iron formations around 2 Gyrs
ago. These _could_ reflect the metabolism of FeO (Fe(2+))
to Fe2O3 (Fe(3+)). So one can _speculate_ (we don't have
the cells or anything like them now as far as I know), one
can speculate that this represents a transition region
between plants and animals. This is because the blue-green
algae would use photosynthesis and could do this conversion
by themselves. They probably didn't need oxygen. So something
was burning he FeO, and that would be cells that couldn't do
photosynthesis. They would need to metabolize O2 and they
need a source of energy to do it. So it is a plausable conjecture
that this is reflecting the beginnings of animal life, but of course
not proof.

There is lots of iron on the earth, like oil today. If we buy into
some version of this conjecture, when there was a lot of FeO,
perhaps cells could make a living this way, but eventually, the FeO
ran out (like oil will), and the cells need to find a better way (or
at least different way) to make a living.

There are many proteins that are common to both plants and
animals: cytochrome C for example. Of course, ribosomal RNA
 is very similar between all life. The universal codon table is
_almost_ universal. So the critical machinery for basic function
does appear in both kingdoms. The differences lie mostly where
they are --- well --- different.

Hope this helps
.... and we are here only by His Grace to think about this...
Wayne

 
Received on Thu Feb 3 18:51:48 2005