Recent research has found the chemical signature of life in rocks
said to be 3.7 billion years, This is 200 Ma earlier than the
earliest known fossils (photosynthetic cyanobacteria). The news
report is at
http://cnn.com/TECH/science/9901/28/science.life.reut/index.html
[snip]
Last year, I participated in discussions on the alleged reducing
atmosphere of the early Earth, and posted a contribution on Archaean
oil. In the latter post, I said:
"I have found this extremely interesting, as it was not that long ago
that the Archaean was portrayed as a world unsuitable for life as we
know it. Now we find evidence that the aqueous Archaean was teeming
with life - with the possibility of using biomarkers to find out more
as to what kinds of life were represented."
This latest study is a significant step in this direction.
Furthermore, since the graphites go back almost to the time of the
great bombardment, the data further constrains theories about the
"Origin of life". The resource of seemingly unlimited time is no
longer available to the advocates of abiogenesis.
My reply:
I do not deny that researchers in the past tried to push the reducing
atmosphere out to several billion years, but as I posted a couple of months
ago, the best evidence indicates that it lasted only 500 to 800 million
years, roughly between 4.5 and 4 billion years ago. As such, this latest
research comes as no surprise to me, and actually helps to support the data
I cited.
As for the implied need for "unlimited time" I would remind everyone that
800 million years covers virtually the entirety of metazoan evolution, from
the simplest hypothetical organisms through the Cambrian explosion on up to
modern times. That is a heck of alot of evolution for so short a time.
Considering the ease with which biomolecules, including catalytic proteins
and RNA, plus vesicles with lipid bilayers, can form, I don't consider 500
million years to be any serious limitation to abiogenesis.
Kevin L. O'Brien