Re: The young age of Earth

Kevin O'Brien (
Sat, 13 Mar 1999 10:21:33 -0700

>I suspect, Kevin, that we are not communicating effectively here. I
>do not think I have made a vague assertion.

Actually, I have never doubted that you believe this. What I am trying to
point out is that your belief is not based on anything concrete, but on
wishful thinking. 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. When I gave you the opportunity
to provide some definate, concrete support for your assertion, however, all
you simply did was repeat your assertion. Assertions that lack necessary
explanatory detail and supporting evidence are both vague and purely

>In order to demonstrate
>the inadequacy of say 650 Ma time for abiogenesis, I need to be
>informed about a viable mechanism.

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

>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.

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), 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?

You don't need to know a specific mechanism to answer this question; let me
give you three possible scenarios.

Scenario 1: Since it would most likely take longer than a million years for
abiogenesis to create suitably complex biomolecules and metabolic systems, a
bolide impact large enough to force abiogenesis to begin again from scratch
occurring once every million years for at least 600 million years (we need
some time for the aliens to work their magic, after all) would prove an
impossible impediment to overcome. Fortunately, the evidence seems to
suggest that impacts that large occurred far less frequently, and that most
such impacts would not have been that hideously catastrophic in any event.
In fact, bolide impacts might have even boosted abiogenesis rather than
destroyed it.

Scenario 2: Had the surface of the earth remained molten until roughly 3.9
GYA, the remaining 100 million years probably would not have been long
enough, especially if the resulting atmosphere and the oceans had the wrong
chemical makeup. However, the current evidence suggests that the surface of
the earth had been cool enough to be solid for at least 500 MY, if not

Scenario 3: Had the entire surface of the earth been covered with ice until
say about 4.0 GYA, this would have severly limited the abiogenetic
mechanisms that could have occurred, which would have increased the time
necessary for integrated metabolic systems to have appeared. Again,
however, the current evidence indicates that the earth had not been
completely covered with ice for any significant period of time.

It is these kinds of scenarios, not ones based on specific mechanisms, that
you would have to present to demonstrate that there would have been
insufficient time for abiogenesis to work.

>In this, my
>argument is essentially the same as Francis Crick ("Life Itself") who
>sought to revive panspermia as a way out of the apparently insoluble
>problem. 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.

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.

>My assertion was ambiguous - sorry. I do not deny that a large
>number of mechanisms have been proposed! Nevertheless, I continue to
>think that the consensus in the research community is that the
>problems have not been solved.

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

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. 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.

Kevin L. O'Brien