> What I am trying to
> point out is that your belief is not based on anything concrete, but on
> wishful thinking.
I recognise that this is your perception of my comments.
> No one has ever denied that abiogenesis has unanswered
> questions; we simply deny that these unanswered questions are fatal,
> especially since the questions we have been able to answer convince us that
> abiogenesis did occur on the early earth.
You have taken me to task for not being specific enough. As someone
who is not convinced by the chemical evolution scenarios, I would
like to do the same to you. What are these "questions that we have
been able to answer"? If I knew what aspects of the research you
find convincing, I might be able to interact more substantially with
you.
I had written:
> >In order to demonstrate
> >the inadequacy of say 650 Ma time for abiogenesis, I need to be
> >informed about a viable mechanism.
You responded:
> You have been informed about several in the past; if memory serves, your
> usual response was simply to repeat your assertion that there would not be
> enough time to allow abiogenesis to occur, with vague references to bolide
> impacts and the supposed difficulty of creating complex biomolecules and
> metabolic systems. At no time have I ever seen you present a detailed
> testable causal explanation, backed up by concrete evidence, of why there
> would be insufficient time for any proposed mechanism of abiogenesis to
> work.
This seems to me a bit like being required to interpret
Nebuchadnezzar's dream! I admit to being inadequate to supply such a
testable causal explanation.
I had written:
> >My argument was: in the absence
> >of a viable mechanism, the prediction must be that abiogenesis cannot
> >happen on Earth - no matter how much time is available.
You responded:
> Ignoring for the moment that this is a classical example of the appeal from
> ignorance fallacy (no mechanism as been found, so abiogenesis must be
> false), ....
I like to think of it as an argument from knowledge. After many
decades of intensive research, we seem no nearer the goal. The
research shows an increasing divide between life and non-life.
> you have implied this argument even when specific mechanism have
> been proposed. As such, it seems to me that you believe the main objection
> to abiogenesis is a lack of time. So I ask again: what testable causal
> mechanism backed up by concrete evidence do you have that demonstrates that
> there would have been insufficient time for abiogenesis to occur?
No. I am not saying that the MAIN objection to abiogenesis is a lack
of time. I am saying that it is a constraint on theories.
> You don't need to know a specific mechanism to answer this question; let me
> give you three possible scenarios.
I take it that you are seeking some specific line of argument from me
along the lines of these three scenarios. I have no appetite for
this, because the logic of the argument is empty unless a specific
mechanism of abiogenesis is in mind. My original point related to
the time constraints within whiuch abiogenesis theories must operate.
I had written:
> > I have followed Crick in his assessment of the achievements
> >of the abiogenesis research - he did not find the argument vague and
> >neither do I.
You replied:
> This is another fallacy: the appeal to authority. Crick is making the same
> mistake you are; the fact that he is Francis Crick, co-discoverer of DNA,
> does not change his error into truth.
I was not so much appealing to authority as suggesting that I was in
good company with someone who is generally regarded as a leader in
science. The conclusions that I have come to are not ones that
should be referred to as an "appeal from ignorance".
> If by "solved" you mean a detailed protocol of how abiogenesis actually
> occurred, containing exact details of what happened when and how, you are
> right. In fact, I will go one better: I assert that such a protocol would
> be impossible to figure out, so the problems would in fact never be
> "solved".
Of course. We agree.
> If, however, by "solved" you mean that we have a number of viable mechanisms
> that demonstrate how abiogenesis could have occurred under certain sets of
> conditions, and that we have evidence that those conditions prevailed on the
> earth at certain points in time for certain periods of time, then you are
> wrong.
Nevertheless, this is what I mean.
> We have enough evidence to demonstrate that abiogenesis is not only
> likely, but probably inevitable, and we have good ideas as to how to
> proceeded. There are still unaswered questions, but the general concensus
> among those who do research in abiogenesis is that most of the problems have
> in fact been solved.
This is the most optimistic assessment of abiogenesis that I have
ever read! I would be interested to obtain some quotations from you
to demonstrate that this is, indeed, the way the abiogenesis research
community view things.
In exchange, I offer below some recent items from BBC online,
demonstrating that there is little consensus as to where the
solutions are to be found.
----------------------------------------------------------
Kick-start for life on earth
Molecules that nurtured the first life on Earth can form in these
interstellar dust clouds By BBC News Online Science Editor Dr David
Whitehouse
Life on Earth may have been kick-started by a meteorite and comet
bombardment of molecular "food", believe some scientists.
The theory has now received support from experiments that show that
the complex chemical compounds life needs can be made in large
quantities in the conditions found in space.
Source:
http://news.bbc.co.uk/hi/english/sci/tech/newsid_282000/282201.stm
---------------
Ocean vents were "factories of life"
The hydrothermal waters cause chimneys of minerals to grow up
A laboratory model of a deep ocean vent has convinced Japanese
scientists that life on Earth began at the bottom of the ocean more
than three and a half billion ears ago.
The team from the Nagaoka University of Technology showed that the
special conditions found in a hydrothermal vent can allow simple
molecules to join up in long chains - a crucial step in producing the
more complex life-giving molecules such as RNA and DNA.
Hydrothermal vents are powered by the heat of submarine volcanoes.
Water is drawn down into the rock, boils and then steams out again
into the cold ocean.
As these parts of the oceans are lined with many vents, particular
molecules can go through the vents many times. This repeated hot and
cold cycling of water was the vital procedure.
Source:
http://news.bbc.co.uk/hi/english/sci/tech/newsid_275000/275738.stm See
also:
http://news.bbc.co.uk/hi/english/sci/tech/newsid_167000/167863.stm
--------------
Tiny mineral test-tubes: the cradle of life?
Is it coincidence that bacteria and microscopic mineral pores are
exactly the same size?
The birthplace for life on Earth may have been labyrinthine networks
of tubes on the surface of rocks.
In these natural test tubes, the complex molecules needed for life
could have evolved in safety, taking its building blocks from the
water washing over the rock and from the minerals within.
New research argues that the pores provide the perfect sheltered
environment for the chain of chemical reactions necessary to evolve
the first bacteria. The proposal, from scientists at the Universities
of Edinburgh and Chicago, also explains how cell walls first
developed: as lids on the pores used to batten down the hatches during
droughts.
The work was welcomed by Dr Graham Cairns-Smith, an expert on origin
of life at the University of Glasgow. "It's a fascinating piece of
mineralogy and I'm all for it," he told BBC News Online.
"The idea that the critical organic reactions would take place in the
open primordial oceans is now very hard to believe."
Source:
http://news.bbc.co.uk/hi/english/sci/tech/newsid_239000/239787.stm
------------------------------------------
Best regards,
David J. Tyler.