Re: [asa] SC Morris piece "Darwin was right. Up to a point."

From: Murray Hogg <muzhogg@netspace.net.au>
Date: Thu Aug 20 2009 - 20:49:02 EDT

Hi Bernie,

I've lent my copy of "Life's Solution" to somebody so can't give the exact quote, but in essence SCM's position is that the origin of first life is highly unlikely but once it begins, the outcomes are predictable.

So he thinks alien life is enormously improbable but that, should it exist, it will closely equate to that found on earth (same problems = same evolutionary solutions).

The full title of his book is, accordingly, "Life's Solution: Inevitable humans in a lonely universe"

This means that (3) below should be qualified along the following lines: "Human life was not unlikely" ***once life has formed***

Or to put it really bluntly: either you get no life at all, or (if you do) you eventually get something essentially identical to humans.

Blessings,
Murray

Dehler, Bernie wrote:
> Does option 3 imply that we should easily find life on other planets too, since life isn't all that special (unlikely)? Seems like 1 and 3 may be able to make a prediction regarding finding life outside our planet.
>
> ...Bernie
>
> -----Original Message-----
> From: asa-owner@lists.calvin.edu [mailto:asa-owner@lists.calvin.edu] On Behalf Of Nucacids
> Sent: Thursday, August 20, 2009 3:43 PM
> To: Austerberry, Charles; asa@lists.calvin.edu
> Subject: Re: [asa] SC Morris piece "Darwin was right. Up to a point."
>
> Here is a short paper that would seem very relevant to this topic: "How much
> of protein sequence space has been explored by life on Earth?"
>
> http://rsif.royalsocietypublishing.org/content/5/25/953.full
>
>
>
> Let me quote the short discussion:
>
>
>
> "Protein sequence space is often viewed as a limitless desert of maladjusted
> sequences with only a few oases of working sequences linked by narrow
> pathways (Axe 2000, 2004). The navigation over this space by natural
> selection is difficult and could take many different routes thus resulting
> in organisms with largely different protein compositions. This idea of
> contingency, if taken at the level of species, led Gould to suggest that if
> one was to rerun the 'tape of life' then evolution would take a totally
> different path and we, as a species, would only appear as a highly
> improbable accident (Gould 1991; Luisi 2003; de Duve 2007a,b). However, if
> there is any merit to our simple calculation then protein sequence analysis
> provides no support for the idea of contingency at a molecular level and it
> provides strong support for the ideas of convergence (Conway Morris 2000,
> 2004; Dawkins 2005; Vermeij 2006; de Duve 2007a,b). If one was to rerun the
> tape, then the protein composition of organisms would be similar. Our
> calculation removes the almost impossibly unrealistic pressure on natural
> selection to navigate through protein sequence space avoiding the vast
> number of functionless sequences by simply indicating that most sequences
> have been tried are useful in some way, and that there are many possible
> routes to obtain proteins with desirable functions (Nagano et al. 2002;
> Anantharaman et al. 2003; Holliday et al. 2007).
>
>
>
> Finally, we conclude that the number 20100 and similar large numbers (e.g.
> Salisbury 1969; Maynard Smith 1970; Mandecki 1998; Luisi 2003; Carrier 2004;
> de Duve 2005) are simply 'straw men' advanced to initiate discussion in the
> same spirit as the 'Levinthal paradox' of protein folding rates (Levinthal
> 1969; Zwanzig et al. 1992). 20100 is now no more useful than the approximate
> 2101?834?097 books present in Borges' (1999) fantastical 'Library of Babel'
> and has no connection with the real world of amino acids and proteins.
> Hence, we hope that our calculation will also rule out any possible use of
> this big numbers 'game' to provide justification for postulating divine
> intervention (Bradley 2004; Dembski 2004)."
>
>
>
> It would thus seem we have three basic positions that can be represented in
> the following crude formulations (using human origins as an illustrative
> example):
>
>
>
> 1. Human life was so unlikely that natural causes cannot account for it (DI
> view).
>
> 2. Human life was very unlikely, but not so unlikely that natural causes
> cannot account for it ("Darwinist" view).
>
> 3. Human life was not unlikely (SCM view).
>
>
>
> 1 and 2 would unite against 3 in denying that human life was likely (both
> play the "big numbers game"). 2 and 3 would unite against 1 in maintaining
> natural causes are not insufficient. 1 and 3 cannot unite against 2 on the
> basis of these positions as stated.
>
>
>
> And there ya go.
>
>
>
> Mike

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Received on Thu Aug 20 20:49:50 2009

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