----- Original Message -----
From: "leaking pen"
why WOULDNT have early aneaorbic life had oxygen as a waste
product?
pretty simple really -- they cannot live on the surface of ice.
The ice surface, then as now, is inhospitable to chlorophyl based
plants or algae and the ice was so thick that the tiny amounds of
O2 which they did make was 'de minimis.'
chlorophyl based plants do, and the compounds involved in
photosynthesis have been shown to occur naturally under certain
conditions.
Again, on an ice covered planet there is simply no place for
chlorophyll based plants or single celled organisms to flourish,
so the O2 content of air was small until the glaciers started to
melt and the HOOH process ensued. Once there was open ocean, then
chlorophyll based life could thrive, but not before that time -
nada.
Perhaps Richard is correct that the reason the ice began to melt
at all was related the thermodynamics of a hot core. That core
could have been heated-up by several possible methods - including
the possibility that earth had a small second moon ... at one
time.
